Institute of Theoretical and Applied Mechanics, v.v.i.Czech Academy of Sciences
Book of AbstractsXVII th Youth Symposium on Experimental Solid Mechanics
Faculty of Transportation SciencesCzech Technical University in Prague
University Centre Telč, Telč, Czech Republic
June 6 th June 8th, 2019
Institute of Theoretical and Applied Mechanics, v.v.i., Czech Academy of Sciences
Faculty of Transportation Sciences, Czech Technical University in Prague
Book of Abstracts
XVIIth Youth Symposium on Experimental Solid Mechanics
University Centre Telc, Telc, Czech Republic
June, 6th - June, 8th 2019
supported by:
Czech Academy of Sciences
Czech Technical University in Prague
under auspices of:
International Measurement Confederation (IMEKO)
Editors: Daniel Kytyr, Tomas Doktor, Petr Zlamal
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
Book of Abstract
Youth Symposium on Experimental Solid Mechanics 2019
Editors: Daniel Kytyr, Tomas Doktor, Petr Zlamal
Publisher:
Institute of Theoretical and Applied Mechanics
Prosecka 809/76
190 00 Prague 9
Acknowledgment:
The conference was supported by Grant Agency of the Czech Technical University in Prague (grant no.
SVK 44/19/F6) and by Czech Academy of Sciences in program “Support for research and educational
activities for youth researchers from abroad” (project no. VVAM-19-04). All the financial support is
gratefully acknowledged.
Sponsored by:
VUZ a.s.
40 pages, issue No. 1
ISBN: 978-80-86246-45-1
DOI: 10.21495/45-1
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YSESM 2019, June 6th – June 8th, Telc, Czech Republic
About YSESM 2019
The YSESM symposium provides a forum for young researchers and engineers, PhD students and students
dealing with subjects of experimental mechanics. The Symposium concentrates on current work in all areas
of experimental research and its application in solid and fluid mechanics. The topic will particularly concern
to:
• Conventional and Advanced Experimental Methods in Solid and Fluid Mechanics
• Non-Destructive Testing and Inspection
• Measurements in Material Science
• Computer Assisted Testing and Simulation
• Engineering Design Simulation
• Hybrid Methods, Experimental Techniques Numerical Simulation
• Optical Methods and Image Processing
• Measurements in Biomechanics
• Sensor Techniques for Micro- and Nano-Applications
YSESM 2019 - Local Organizing Committee:Tomas Doktor, Jan Falta, Ivana Kumpova, Daniel Kytyr, Michaela Neuhauserova, Petr Zlamal
YSESM 2019- Scientific Committee:Lajos Borbas, Matej Borovinsek, Tomas Doktor, Marc Gutermann, Stephen Hall, Daniel Kytyr, Dagnija
Loca, Zoltan Major, Giangiacomo Minak, Martin Reiter, Sascha Senck, Jacek Tarasiuk, Petr Zlamal
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YSESM 2019, June 6th – June 8th, Telc, Czech Republic
Symposium Programme
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YSESM 2019, June 6th – June 8th, Telc, Czech Republic
Schedule of Lectures
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YSESM 2019, June 6th – June 8th, Telc, Czech Republic
Contents
EVALUATION OF HOPKINSON BAR EXPERIMENTS USING SEVERAL DIGITAL IMAGE
CORRELATION TOOLS 9
M. Adorna, J. Falta, P. Zlamal, T. Fıla
A TEST BENCH FOR THE EXPERIMENTAL CHARACTERIZATION OF SOLID TRUCK
WHEELS: DESIGN, PROTOTYPE, AND VALIDATION 10
C. Barone, D. Castagnetti, A. Spaggiari, E. Dragoni, F. Ascari, F. Monica, A. Perrone
MECHANICAL AND OPTICAL INVESTIGATION OF LASER WELDED STRUCTURAL STEEL
PMMA HYBRID JOINT STRUCTURES 11
T. Csiszer, T. Temesi, L. Molnar
MULTIAXIAL INVESTIGATION OF PVC FOAMS AND ANALYSIS OF THE DEFORMATION
MECHANISM BY 3D-DIC 12
F. Concas, S. Diebels, A. Jung
HIGH STRAIN-RATE COMPRESSIVE TESTING OF FILLING MATERIALS FOR INTER-
PENETRATING PHASE COMPOSITES 13
T. Doktor, T. Fıla, P. Zlamal, P. Koudelka, D. Kytyr, O. Jirousek
IMPACT RESISTANCE OF COMPOSITES WITH DIFFERENT TYPES OF INCLUSIONS 14
K. K. Dudek
NUMERICAL MODELLING OF WAVE SHAPES DURING SHPB MEASUREMENT 15
R. Dvorak, P. Koudelka, T. Fıla
DIRECT MEASUREMENT OF REACTION FORCES DURING FAST DYNAMIC LOADING -
APPLICATIONS FOR SHPB AND ITS MODIFICATION 16
J. Falta, M. Adorna, T. Fıla, P. Zlamal
CUSTOM-MADE RHEOMETER FOR THE EXPERIMENTAL STUDY OF POLYURETHANE
RESIN PU9010 17
L. Fissore, S. Diebels
ADDITIVE MANUFACTURING PROCESS PARAMETER INFLUENCE ON MECHANICAL
STRENGTH OF ADHESIVE JOINTS, PRELIMINARY ACTIVITIES 18
M. Frascio, L. Bergonzi, F. Moroni, A. Pirondi, M. Avalle, M. Monti, M. Vettori
IN-SITU COMPRESSION TEST OF ARTIFICIAL BONE FOAMS IN CONTROLLED ENVI-
RONMENT USING X-RAY MICRO-COMPUTED TOMOGRAPHY 20
J. Glinz, D. Kytyr, T. Fıla, J. Sleichrt, A. Schrempf, D. Furst, J. Kastner, S. Senck
REFRACTIVE-INDEX-CORRECTED 3D SUPER RESOLUTION MICROSCOPY OF CELLS 21
F. Hauser, J. Jacak
EXPERIMENTAL INVESTIGATION AND SIMULATION OF 3D-PRINTED LATTICE STRUC-
TURES 22
E. Heiml, A. Kalteis, Z. Major
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YSESM 2019, June 6th – June 8th, Telc, Czech Republic
COMBINED APPROACH OF TOPOLOGY AND PARAMETER OPTIMIZATION FOR THE
DESIGN OF LIGHTWEIGHT MULTICOPTER DRONES 23
F. Kiehas, M. Reiter
MECHANO-BIOLOGICAL DEFORMATION RESPONSE OF MESENCHYMAL STEM CELLS
ADHERED TO POLYDIMETHYL-SILICONE MEMBRANES 24
B. Kronsteiner, M. Pasztorek, E. Rossmanith, M.B. Fischer, W. Baumgartner
STRAIN MEASUREMENT ON 2124-T851 ALUMINUM NOTCHED BAR SPECIMENS BY DIG-
ITAL IMAGE CORRELATION METHOD 25
M. Lutovinov, J. Papuga, J. Kuzelka
DEFORMATION RESPONSE OF POLYDIMETHYLSILOXANE SUBSTRATES SUBJECTED
TO UNIAXIAL QUASI-STATIC LOADING 26
F. Martino, V. Vinarsky, J. Sleichrt, D. Kytyr
INVERSE COMPUTATIONAL DETERMINATION OF JOHNSON-COOK PARAMETERS US-
ING THE SHPB TEST APPARATUS 27
A. Mauko, B. Necemer, Z. Ren
A PENDULUM ELECTROMAGNETIC ENERGY HARVESTER 28
M. Mistrulli, D. Castagnetti
LIGHTWEIGHT AUXETIC METAMATERIALS DESIGNED THROUGH TRUSS NETWORKS 29
L. Mizzi, A. Spaggiari
STRAIN RATE DEPENDENCY OF COMPRESSIVE BEHAVIOUR OF 3D PRINTED SS316L
BULK SPECIMENS WITH RESPECT TO PRINTING DIRECTION 30
M. Neuhauserova, P. Koudelka, J. Falta, M. Adorna, T. Fıla, P. Zlamal
MECHANICAL AND STRUCTURAL PROPERTIES OF COLLAGEN NANOFRIBROUS LAY-
ERS UNDER SIMULATED BODY CONDITIONS 31
J. Rıhova, T. Suchy, L. Vistejnova, L. Horny, M. Supova
DESIGN AND VALIDATION OF A MINIMALLY INVASIVE ADJUSTABLE TITANIUM PROS-
THESIS AS A VERTEBRAL BODY REPLACEMENT 32
A. Sorrentino, D. Castagnetti, F. Taddei, E. Schileo
DEVELOPMENT OF AN INJECTION MOULDING SIMULATION ALGORITHM TO CON-
SIDER THE EFFECT OF SEGREGATION DURING INJECTION MOULDING 33
T. Temesi, L. Szabo
WIND TUNNEL TESTS FOR LIFETIME ESTIMATION OF BRIDGE AND MAST CABLES
EXPOSED TO VORTEX INDUCED VIBRATIONS 35
A.Trush, S.Pospısil, S. Kuznetsov
FEASIBILITY STUDY: MULTIPHOTONLITHOGRAPHY 36
M. Wimmer
SIMULATION AND OPTIMIZATION OF POROUS BONE-LIKE MICROSTRUCTURES WITH
SPECIFIC MECHANICAL PROPERTIES 37
A. Wit, S. Wronski, J. Tarasiuk
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YSESM 2019, June 6th – June 8th, Telc, Czech Republic
EVALUATION OF HOPKINSON BAR EXPERIMENTS USING SEVERAL DIGITAL
IMAGE CORRELATION TOOLS
M. Adorna 1 , S. Bronder 2 J. Falta, P. Zlamal, T. Fıla
Keywords: Digital Image Correlation, Hopkinson Bar, impact loading, high-speed imaging
Abstract
In this paper, several different tools for Digital Image Correlation (DIC) were used for evaluation of dynamic
experiments performed using custom Open Hopkinson Pressure Bar (OHPB) apparatus. High strain-rate
measurements were performed on specimens of advanced cellular materials with predefined structure and
negative Poissons ratio (so called auxetic structures). These specimens were manufactured by electrodepo-
sition of a nickel coating on a base structure produced by 3D printing of polymer (coating layer thickness
of approx. 60µm and 120µm). Low impedance polymethyl methacrylate (PMMA) bars instrumented with
both foil and semiconductor strain-gauges were used for dynamic loading of the specimens. Experimets were
observed using a pair of high-speed cameras (frame rate set to 270 kfps) for imaging of loading process in suf-
ficient quality. Precise synchronisation of the high-speed cameras and the strain-gauge record was achieved
using a through-beam photoelectric sensor. Custom developed evaluation DIC tool [1] implemented in Mat-
lab, open-source Matlab tool [2] and commercial DIC software (ISTRA 4D) were all used for evaluation of
image sequences recorded by high-speed cameras. Coprarison of results obtained using all three different
DIC tools and results of complementary strain-gauge measurement are shown in this paper. Verification of
prescision and reliability of custom made DIC software tool is presented.
Acknowledgment
The research was supported by the Czech Science Foundation (project no. 19-23675S) and the internal grants
of the Czech Technical University in Prague (projects no. SGS18/153/OHK2/2T/16 and
SGS18/154/OHK2/2T/16). All the financial support is gratefully acknowledged.
References
[1] Jandejsek, I. et al. Optimization and Calibration of Digital Image Correlation Method. Experimentalni
analyza napeti 2010, 121-126, 2010.
[2] Blaber, J. et al. Ncorr: Open-Source 2D Digital Image Correlation Matlab Software. Experimental
Mechanics 2015, 55(6), DOI: 10.1007/s11340-015-0009-1. ISSN 0014-4851.
1Ing. Marcel Adorna, CTU in Prague, Faculty of Transportation Sciences, Department of Mechanics and Materials, Konviktska
20, 120 00 Prague 1, Czech Republic, email: [email protected] des Saarlandes, Institute of Applied Mechanics, Campus A4.2, Saarbrucken, 66123, Germany
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YSESM 2019, June 6th – June 8th, Telc, Czech Republic
A TEST BENCH FOR THE EXPERIMENTAL CHARACTERIZATION OF SOLID
TRUCK WHEELS: DESIGN, PROTOTYPE, AND VALIDATION
C. Barone, D. Castagnetti, A. Spaggiari, E. Dragoni 1 F. Ascari, F. Monica, A. Perrone 2
Keywords: solid truck wheels, experimental characterization, operating conditions test
bench, design, prototype, predictive model
Abstract
Solid wheels are extensively used in automated and manual industrial trucks for goods movimentation, thanks
to their versatility. They have a composite structure: a metal body, which provides structural support, coated
with elastomeric polyurethane o rubber, giving grip and resilience. Elastomeric polyurethane, being ex-
tremely versatile, abrasion resistant and available in a wide range of hardnesses, is preferred over rubber in
applications that require a more durable coating, and a stiffer wheel for an accurate motion control. The
aim of this work is to design, develop and validate a test bench for the experimental characterization of solid
wheels, simulating the real behaviour in exercise, and consequently diagnose and reproduce the causes of
failure. The test bench must be able to manage and reproduce the typical operating conditions of the wheel,
for example: the load carried by the wheel, the speed, the type of pavement, the ambient temperature, and the
contaminants. The design of the test bench was performed according to the Quality Function Deployment
procedure, and organized in the following steps: identification of the customer needs and technical specifica-
tions, concepts generation and design implementation. The test bench features a rotating circular plate, 5 m in
diameter, on which four different pavements can be installed: steel, concrete, ceramic, asphalt. Four simple
frame structures, angularly equispaced, support the wheels close to the outer radius of the circular plate. On
each frame, an actuator loads the wheel against a plane pavement, as in real conditions, with a maximum
load on the wheel equal to 100 kN, either static or dynamic. The maximum speed of the wheel is 5 m/s and
both idle wheels or drive wheels can be tested: in case of idle wheels, an external drive acts the circular plate
which consequently drive the wheels; in case of drive wheels, the actuation of the wheels causes the rotation
of the circular plate. The test bench, able to accommodate wheels ranging from 200 mm up to 600 mm in
diameter, will allow to develop a predictive model of the wheel response in typical operating conditions and
to describe either the abrasion, the mechanical fatigue or the thermomechanical fatigue of the wheels.
1Department of Sciences and Methods for Engineering - University of Modena and Reggio Emilia Via G. Amendola, 2 - 42122
Reggio Emilia - Corresponding Author Calogero Barone, Univ. of Modena and Reggio Emilia, Via G. Amendola 2, 42122 Reggio
Emilia, Italy. E-mail:[email protected] Via G. Marconi, 23 42030 Viano (RE) Italy
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YSESM 2019, June 6th – June 8th, Telc, Czech Republic
MECHANICAL AND OPTICAL INVESTIGATION OF LASER WELDED STRUCTURAL
STEEL PMMA HYBRID JOINT STRUCTURES
T. Csiszer 1 T. Temesi 2 L. Molnar 3
Keywords: laser welding, metal-polymer hybrid structures, poly(methyl-methacrylate)
Abstract
The reduction of costs, both in the manufacturing processes and throughout the lifespan of a vehicle is an
important aim of the vehicle industry. One possible method to achieve this is to use materials with lower den-
sity, such as using aluminum, or even polymers and polymer composites instead of steel. Modern, productive
welding processes that can easily be automated (such as friction stir welding, laser welding and ultrasonic
welding) are gaining popularity in joining metal-polymer hybrid structures [1]. In all of these processes, the
polymer material is heated until it is able to bond to the metal surface, however the procedure and cause of the
bonding process itself is not yet well-discussed in scientific publications. This field of science is intensively
studied around the globe, as a dependable, productive joining method that directly produces structurally sound
joints between a metal and a polymer structure could unleash unforeseen potential and possibilities in the ve-
hicle industry [2, 3]. In our experiments, we manufactured hybrid steel-poly(methyl-methacrylate) (PMMA)
joints with laser welding, using the 2p design of experiment method. We measured the shear strength of the
joints, the effect of welding parameters and cellulose fibres (in varying weight percentages) on the mechani-
cal properties of the joint and the degradation of the PMMA material and examined the seam with scanning
electron microscopy.
Acknowledgment
This research was supported by the grant No. EFOP-3.6.1-16-2016-00009.
References
[1] Amancio-Filho S. T., Blaga L.: Joining of polymer-metal hybrid structures - principles and applications.
John Wiley and Sons, Inc., Hoboken, New Jersey, USA, 2018.
[2] Amend P., Pfindel S., Schmidt, M.: Thermal joining of thermoplastic metal hybrids by means of mono-
and polychromatic radiation. Physics Procedia, 41, p. 98-105, 2013.
[3] Chen, Y.J., Yue, T.M., Guo, Z.N.: A new laser joining technology for direct-bonding of metals and
plastics. Materials and Design, 110, p. 775-781, 2016.
1Tamas Csiszer PhD, Engineering Institute, Edutus University, Studium ter 1., Tatabanya, H-2800, Hungary and Rejto Sndor
Faculty of Light Industry and Environmental Protection Engineering, buda University, Doberdo ut 6, H-1034, Budapest, Hungary,
email: [email protected] Temesi, PhD student, Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of
Technology and Economics, Muegyetem rakpart 3, Budapest, H-1111, Hungary, email: [email protected] Molnar, Engineering Institute, Edutus University, Studium ter 1., Tatabanya,, H-2800, Hungary,
email: [email protected]
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YSESM 2019, June 6th – June 8th, Telc, Czech Republic
MULTIAXIAL INVESTIGATION OF PVC FOAMS AND ANALYSIS OF THE
DEFORMATION MECHANISM BY 3D-DIC
F. Concas 1 , S. Diebels 2 , A. Jung 3
Keywords: polymeric foams, multiaxial testing, three-dimensional digital image correla-
tion
Abstract
Closed-cell polyvinychloride (PVC) foams are widely used as core for sandwich composites, especially for
the construction of marine vessels and wind turbine blades. In the above-mentioned applications, the foam
core undergoes multiaxial loading conditions. The investigation of the multiaxial mechanical properties
of PVC foams has been the main topic of several works. Nevertheless, there is a lack of analysis on the
multiaxial response of high performance PVC foams, particularly in the case of simultaneous tensile and
torsional loading. The present work gives a contribution in this field through the application of a wide range
of uniaxial and multiaxial experiments on a high performance PVC foam with the trade name of Divinycell
HP100 (DIAB AB, Sweden). The conducted experiments included: pure tension, pure compression and pure
torsion, simultaneous tension-torsion as well as simultaneous compression-torsion. All experiments were
performed on the same cylindrical geometry. Failure data for each experiment were collected and depicted in
the invariants plane. The yield function proposed by Bier et al. [1, 2] was successfully adapted to failure data
of the foam. The occurrence and the evolution of deformation bands of PVC foams during multiaxial loading
were also analysed by three-dimensional digital image correlation (3D-DIC) with an 8-camera system, which
allows the monitoring of 360◦ of the specimen surface. Despite of the simple specimen geometry. The usage
of an 8-camera system was essential for the observation of the deformation mechanism, especially for pure
compression, pure torsion and combined axial-torsional loading cases. In the aforeseen experiments, the
arising of deformation bands is affected by buckling and by the orthotropy of the foam, respectively.
References
[1] Bier, W. et al. A finite strain constitutive model for metal powder compaction using a unique and convex
single surface yield function. European Journal of Mechanics-A/Solids 25 (6), p. 1009-1030 (2006).
[2] Bier, W. et al. Die compaction of copper powder designed for material parameter identification. Inter-
national Journal of Mechanical Sciences 49 (6), p. 766-777 (2007)
1Dr. Francesca Concas, Chair of Applied Mechanics, Saarland University, Campus A4.2, 66123 Saarbrucken, Germany,
email: [email protected]. Dr.-Ing. Stefan Diebels, Chair of Applied Mechanics, Saarland University, Campus A4.2, 66123 Saarbrucken, Germany,
email: [email protected] Dr.-Ing. Dr. rer. nat. Anne Jung, Chair of Applied Mechanics, Saarland University, Campus A4.2, 66123 Saarbrucken,
Germany, email: [email protected]
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YSESM 2019, June 6th – June 8th, Telc, Czech Republic
HIGH STRAIN-RATE COMPRESSIVE TESTING OF FILLING MATERIALS FOR
INTER-PENETRATING PHASE COMPOSITES
T. Doktor, T. Fıla, P. Zlamal, P. Koudelka, D. Kytyr, O. Jirousek 1
Keywords: interpenetration phase composite, SHPB, strain energy density
Abstract
Cellular materials or open cell metal foams pose favourable impact energy absorption properties [1] which
may be enhanced when their porous structure is equipped with a suitable filling material to form inter-
penetrating phase composite (IPC). The filling has to provide a good strain energy absorption with acceptable
increase of the overall density of such IPC. In this study behavior of selected types of filling material were
tested in compressive loading mode at low and high strain rates.
Three types of filling material were tested, (i) ordnance gelatin, (ii) low expansion polyurethane foam, and
(iii) thixotropic polyurethane putty. To evaluate their impact energy absorption bulk samples of the selected
materials were tested in compression loading mode at strain rates 1000 s−1 to 4000 s−1.
The high strain rate compressive loading was provided by Split Hopkinson Pressure Bar (SHPB) [2]
which was equipped with PMMA bars to enable testing of cellular materials with low mechanical impedance.
From the records of strain-gages signal stress-strain diagrams of tested materials were obtained and subse-
quently, their plateau stress, plateau strain and strain energy density was evaluated and compared with results
of quasi-static tests.
Based on the comparative measurement response to compressive loading at both low and high strain rates
in three types of materials were analysed. The obtained results show a significant strain rate sensitivity in
ordnance gelatin and in polyurethane putty. Strain rate effect in polyurethane foam was not observed in the
investigation.
Acknowledgment
The financial support of the Czech Science Foundation (project No. 19-23675S).
References
[1] Qiao, P., Yang, M., Bobaru, F. Impact Mechanics and High-Energy Absorbing Materials: Review.
Aerospace Engineering 21, 235248 (2008).
[2] Hopkinson, B. A Method of Measuring the Pressure Produced in the Detonation of High Explosives or
by the Impact of Bullets. Phil. Trans. R. Soc. Lond. A 213, 437-456 (1914).
1Ing. Tom Doktor, Ing. Tom Fıla, Ing. Petr Zlamal, Ph.D., Ing. Petr Koudelka, doc. Ing. Daniel Kytyr, Ph.D., prof. Ing. Ondej
Jirousek , Ph.D., Czech Technical University in Prague, Faculty of Transportation Sciences, Department of Mechanics and Materials,
Konviktska 20, 120 00 Prague 1, Czech Republic, email: [email protected]
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YSESM 2019, June 6th – June 8th, Telc, Czech Republic
IMPACT RESISTANCE OF COMPOSITES WITH DIFFERENT TYPES OF INCLUSIONS
K. K. Dudek 1
Keywords: composites, impact resistance, mechanical metamaterials
Abstract
In this work, through numerical studies, I investigate the effect that the use of different types of inclusions
has on protective properties of a particular type of an elastic composite. As a result of my studies, I show
that the use of a certain class of inclusions may significantly enhance impact resistance of a given material.
I also show that depending on the properties of the implemented inclusions, the response of the material to a
collision with an external body may be very different which allows to choose a specific type of inclusions for
a given type of an application. Finally, it is shown that the use of the concept proposed in this work may be
used in order to increase the efficiency of the conventional protective devices.
Acknowledgment
K.K.D. acknowledges the financial support from the program of the Polish Minister of Science and Higher
Education under the name Regional Initiative of Excellence in 2019 - 2022, project no. 003/RID/2018/19,
funding amount 11 936 596.10 PLN.
1Institute of Physics, University of Zielona Gora, ul. Szafrana 4a, 65-069 Zielona Gora, Poland, email: [email protected]
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YSESM 2019, June 6th – June 8th, Telc, Czech Republic
NUMERICAL MODELLING OF WAVE SHAPES DURING SHPB MEASUREMENT
R. Dvorak 1 , P. Koudelka 2 , T. Fıla 3
Keywords: SHPB, pulse shaping, FE simulation
Abstract
The paper aims at the theory and a numerical simulation of the wave propagation through one-dimensional
continuum represented by the SHPB apparatus. The work focus mainly on SHPB principles, optimisation of
a numerical model and techniques of pulse shaping [1]. The parametric model of the typical SHPB configu-
ration developed for LS-DYNA environment is introduced and optimised (distribution and refinement of the
mesh) using the sensitivity study. Then, a parametric analysis of a geometric properties of the pulse shaper
is carried out to reveal of their influence on a shape of the incident pulse [2]. The analysis is algorithmized
together with the processes involved, and thus, automated processing of results and a comparison with the
experimental data is enabled. Results of the parametric analysis and the amount of the influence of geometric
properties of the pulse shaper on the incident wave are demonstrated as well as automation procedure for
creating models, rendering the simulations, and evaluation of outcomes.
Acknowledgment
The research has been supported by Czech Science Foundation (research project No. 19-23675S).
References
[1] Chen, W.W.: Split Hopkinson (Kolsky) bar: design, testing and applications. Springer, New York, 2011.
Mechanical engineering series. ISBN 978-1-4419-7981-0.
[2] Naghdabadi et al. Experimental and numerical investigation of pulse-shaped split Hopkinson pressure
bar test. Material Science and Engineering A.(539), p.285-293 (2012).
1Bc. Radim Dvorak, Czech Technical University in Prague, Faculty of Transporation Sciences, Konviktska 20 Prague 1, 110 00,
email: [email protected]. Petr Koudelka, Czech Technical University in Prague, Faculty of Transporation Sciences, Konviktska 20 Prague 1, 110 00,
email: [email protected]. Tomas Fıla, Czech Technical University in Prague, Faculty of Transporation Sciences, Konviktska 20 Prague 1, 110 00,
email: [email protected]
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YSESM 2019, June 6th – June 8th, Telc, Czech Republic
DIRECT MEASUREMENT OF REACTION FORCES DURING FAST DYNAMIC
LOADING - APPLICATIONS FOR SHPB AND ITS MODIFICATION
J. Falta, M Adorna, T. Fıla, P. Zlamal 1
Keywords: force transducer, SHPB, dynamic loading, instrumentation
Abstract
The presented paper is focused on embedding of the serially manufactured piezo-electric impact load-cell into
Split Hopkinson Pressure Bar (SHPB) for a direct force measurement during dynamic loading. Convention-
ally, during the SHPB test dynamic force equilibrium is investigated by a comparison of the transmitted signal
wave and the difference between the incident and reflected signals waves to the incident bar, measured by
strain gauges [1]. However, in the experiments with specimens with low
mechanical impedance, a major portion of the incident wave is reflected back on the boundary between the bar
and the specimen. Comparison between two-large amplitude incident and reflected pulse and
a small-amplitude transmitted pulse can be influenced by large error and resulting force equilibrium can
be inaccurate. Therefore, a piezo-electric quartz impact force transducer was used to directly measure the
axial forces in the vicinity of the specimen end surfaces, allowing to analyze the force equilibrium which
is an essential characteristic for reliable measurement. Measured values from strain gauges were compared
with values obtained from force transducer, to verify the validity of the acquired signals which will increase
the reliability of the measured data. The presented solution will help to determine the mechanical properties
of advanced materials which is necessary for investigation of complex modern material structures behaviour.
Acknowledgment
The research was supported by the Czech Science Foundation (project no. 19-23675S) and the internal grants
of the Czech Technical University in Prague (project no. SGS18/153/OHK2/2T/16 and
SGS18/154/OHK2/2T/16). All the financial support is gratefully acknowledged.
References
[1] Fıla, T. et al. Testing of Auxetic Materials Using Hopkinson Bar and Digital Image Correlation. DYMAT
2018 - 12th International Conference on the Mechanical and Physical Behaviour of Materials under
Dynamic Loading, EPJ Web Conf. Volume 183, 2018.
1Ing. Jan Falta, Czech Technical University in Prague, Faculty of Transportation Sciences, Department of Mechanics and Mate-
rials, Konviktska 20, 120 00 Prague 1, Czech Republic, email: [email protected]
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YSESM 2019, June 6th – June 8th, Telc, Czech Republic
CUSTOM-MADE RHEOMETER FOR THE EXPERIMENTAL STUDY OF
POLYURETHANE RESIN PU9010
L. Fissore 1 , S. Diebels 2
Keywords: rheology, curing, dynamics
Abstract
Polymers are extensively studied and used due to their high versatility, high specific properties and wide-range
applications. Polyurethane resins are well-known examples in aerospace industry, electronics and automo-
tive as an adhesive or coating because of their broad spectrum of properties. The polymeric system PU9010
is obtained by mixing diisocyanate (Desmodur VP.PU 1806), a diol (Baygal K55) and a triol (Desmophen
3600Z). They are obtained by a process called curing, where in the initial uncured state the mixture exhibits
a viscous behavior and at the end of the polymeric reaction, a solid with viscoelastic properties is formed.
The shrinkage due to cross-linking and the temperature applied to the system cause the generation of residual
stresses which often result in broken adhesive layers. Therefore, the reduction of such problems is of utmost
importance. Hence, studying changes in mechanical properties during curing is important. The mentioned
phase transition can be studied applying an oscillatory strain or stress during the chemical reaction.
In this study, a rheometer capable to conduct such oscillatory-strain-controlled experiments was built in order
to apply large deformations not only to the sample at the beginning of the reaction but also to the cured, solid,
adhesive without changing the device. The design of the machine makes this possible using a Crank - Slider
- mechanism attached to a lever in order to reduce the needed force and therefore be able to apply high torque
at high frequency. Given the fact that the chemical reaction is highly sensitive to moisture in air and fast,
the polymeric system also influences the design of the machine. For this reason, the rheometer as well as the
working place must fit inside a box with controlled atmosphere.
The effect of using Slider - Crank mechanism increases the dynamic forces on the sample but they were
reduced to low values using a lever arm capable of changing the distance of force application. As a conse-
quence, a same deformation can be applied but with smaller amplitude. The testing device works as expected
and the design allows to use small motors to generate big torques.
1Ing. Luciano Fissore, Chair of Applied Mechanics, Universitat des Saarlandes, Campus A4.2 66123, Saarbrucken, Germany,
email: [email protected]. Dr.-Ing. Stefan Diebels, Chair of Applied Mechanics, Universitat des Saarlandes, Campus A4.2 66123, Saarbrucken,
Germany, email: [email protected]
17
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
ADDITIVE MANUFACTURING PROCESS PARAMETER INFLUENCE ON
MECHANICAL STRENGTH OF ADHESIVE JOINTS, PRELIMINARY ACTIVITIES
M. Frascio 1 , L. Bergonzi 2 , F. Moroni 3 , A. Pirondi 4 , M. Avalle 5 , M. Monti 6 , M. Vettori 7
Keywords: additive manufacturing, FFF, bonded joints, surface characterization
Abstract
The work illustrates how building parameters of the Additive Manufacturing (AM) process fused filament
fabrication can affect not only the mechanical properties [1] but also the surface wettability and morphology.
Wettability and morphology are relevant factors in bonded joints performance [2]. Advantages of polymeric
AM are to allow a re-design of components with locally controlled properties [3] and integrated functions.
Major limitations are related to the lack of material testing standardization and constraints due to the build
volume and to the object orientation for printability: the latter problem can be addressed with the use of
bonded joints that allow to create bigger assemblies from smaller parts optimally designed to take advantage
of the anisotropy of the material and without the structural drawbacks due to other joining method, such as
stress concentration in bolted joints. As for the Mechanical properties, they are obtained with uniaxial tensile
tests using MaCh3D [4], an innovative cost effective solution for materials testing. The as built surface
properties are investigated quantitatively and qualitatively using a plate specimen of 15 × 15 × 1.2mm.
Roughness parameters are measured by surface scanning with a CCI Taylor-Hobson 3D optical profilometer
while contact angle values between specimens and a drop of Milli-Q water are measured in order to evaluate
wettability. Different materials, such as ABS and PLA, are characterized at different combinations of nozzle
temperature, print speed and layer thickness. The analysis of the collected data provide information on how
building parameters can modify two fundamental aspects in adhesive joints such as surface roughness and
wettability in order to maximize joint performance.
Acknowledgment
This research was supported by Universit degli studi di Genova, Universit degli studi di Parma, MaCh3D srl.
References
[1] Frascio, M. et al. Fatigue strength of plastics components made in additive manufacturing: first experi-
mental results. Procedia Structural Integrity 12, S32-S43, (2018).
1Ing. Mattia Frascio, Universit degli studi di Genova, Via Opera Pia 15a, email: [email protected]. Lorenzo Bergonzi, Universit degli studi di Parma, MaCh3D srl, email: [email protected]. Fabrizio Moroni, PhD, Universit degli studi di Parma, email: [email protected]. Ing. Alessandro Pirondi, PhD, Universit degli studi di Parma, email: alessandro.pirondi@unipr5Prof. Ing. Massimiliano Avalle, PhD, Universit degli studi di Genova, Via Opera Pia 15a ,email: [email protected]. Margherita Monti, PhD, Universit degli studi di Genova, Via Opera Pia 15a, email: [email protected]. Matteo Vettori, PhD, MaCh3D srl, email: [email protected]
18
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
[2] Arenas Reina, J.M. et al. Influence of the Surface Finish on the Shear Strength of Structural Adhesive
Joints and Application Criteria in Manufacturing Processes. The Journal of Adhesion 6, S324-S340
(2008).
[3] Li, L. et al. Composite Modeling and Analysis for Fabrication of FDM Prototypes with Locally Con-
trolled Properties. Journal of Manufacturing Processes 4, S129-S141 (2002).
[4] Bergonzi, L. et al. Numerical and experimental validation of a non-standard specimen for uniaxial
tensile test. Procedia Structural Integrity 12, S392-S403, (2018).
19
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
IN-SITU COMPRESSION TEST OF ARTIFICIAL BONE FOAMS IN CONTROLLED
ENVIRONMENT USING X-RAY MICRO-COMPUTED TOMOGRAPHY
J. Glinz 1 , D. Kytyr 2 , T. Fıla2, J. Sleichrt2, A. Schrempf 3 , D. Furst3, J. Kastner1, S. Senck1
Keywords: x-ray micro-computed tomography, artificial bone foams, in-situ testing
Abstract
X-Ray Micro-computed tomography (XCT) has already become a standard method for investigations of bone
and bone replacement materials in medical research. For an in-depth characterization of histomorphometric
features, digital volume data acquired by XCT can be processed and visualized three dimensionally to deter-
mine parameters such as bone volume fraction, cortical thickness and porosity. In this study, we investigated
specimens of artificial bone foams, developed by the research group for surgical simulators at the UAS Linz,
which are used to mimic the haptic feedback of physiologic and pathologic bone for more realistic surgery
training. Similar specimen of artificial bone foam in a dry state have already been characterized precisely
in [1]. However, since physiological bone typically is in a wet state, the main purpose of this study was the
investigation of the influence of environmental conditions on artificial bone foams of varying composition.
Thus, specimens with two kinds of mineral filler material as well as different amounts of foaming agent were
prepared and tested in an in-situ loading stage developed by the ITAM CAS. In this stage, specimens can
be immersed in liquid and tested under temperature-controlled conditions. Consequently, a total amount of
12 specimens was subjected to compression loading; half of them immersed in water at 36.5◦C and half in
dry condition. Results showed that there is no significant influence of liquid immersion to the compression
outcome. However, foams with less amount of foaming agent appeared to have smaller pores resulting in
higher compression strength. Different types of mineral filler material also showed no significant influence
on compression strength. Furthermore, a time-lapse in-situ investigation with XCT scans in-between the load
steps was performed for one specimen immersed in water to investigate behavior during load. Despite of the
open porous morphology of the foam, water immersed only partially into the foam, leaving pores closer to the
center unfilled. Concluding, the usage of the artificial bone foams investigated is despite their physiologically
wet condition also valid in a dry state since environmental differences are nonessential for their mechanical
properties.
Acknowledgment
This work is supported by the project Competence Center for High-Resolution 3D X-ray Imaging (Com3d-
XCT) and the European Regional Development Fund (EFRE) in the framework of the Interreg V program
’Austria-Czech Republic’.
References
[1] D. Furst, S. Senck, M. Hollensteiner, B. Esterer, P. Augat, F. Eckstein, A. Schrempf, Characterization
of synthetic foam structures used to manufacture artificial vertebral trabecular bone, Materials Science
and Engineering C 76, p1103-p1111 (2017).
1University of Applied Sciences Upper Austria, Stelzhamerstrae 23, 4600 Wels, Austria, email: [email protected] of Theoretical and Applied Mechanics of the Czech Academy of Sciences, Proseck 76, Prague 9, Czech Republic3University of Applied Sciences Upper Austria, Garnsionstrasse 21, 4020 Linz, Austria
20
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
REFRACTIVE-INDEX-CORRECTED 3D SUPER RESOLUTION MICROSCOPY OF
CELLS
F. Hauser 1, J. Jacak2
Keywords: 3D super resolution microscopy, phase retrieval, tomography
Abstract
Conventional microscopy allows robust imaging of cells used in many laboratories. Relatively large cell
features such as the nucleus and some organelles are observable, but not clearly distinguishable. Best contrast
is possible via fluorescence microscopy by labeling of individual proteins with fluorescent dyes. However,
only a resolution of about 250 nm is possible due to the diffraction limit and details like the actin cytoskeleton
cannot be resolved. Single Molecule Localization Microscopy (SMLM) based on direct Stochastic Optical
Reconstruction Microscopy (dSTORM) overcomes this limitation and allows a resolutions down to 15 nm
[1]. By mounting a cylindrical lens in the optical detection pathway, dSTORM can be extended to the third
dimension. Nevertheless, for imaging of the whole cell or even cell clusters the astigmatic point spread
function (PSF) is insufficient in the axial direction and the sample has to be scanned axially at defined steps.
Thereby, the sample is divided in multiples slices consisting of 10 000 - 20 000 frames of stochastically
blinking single molecules at a defined axial step. However, due to the refractive index mismatch between
sample medium and objective, the PSF is asymmetrically axially distorted due to spherical aberration. These
aberrations cause large gaps between observed and real axial positions, especially for large image depths.
We developed software tools for correction of these aberrations which allows the application of standard
software for astigmatic 3D Super Resolution Microscopy analysis (e. g. RapidSTORM, ThunderSTORM, 3D
STORM Tools). The calibration needed for z-position determination based on the elliptical distortion of the
PSF is recalculated using an enhanced modeling of the PSF which accounts for the refractive index mismatch.
The PSF model is determined by phase retrieval of the original calibration stack of single molecules using
algorithms based on ZOLA-3D [2]. The calibration PSF for each slice is simulated using the information
from the phase retrieval and applied to create refractive-index-corrected calibrations at the specific axial
height. Therefore, a reconstruction of the whole sample with less artifacts is yielded.
Acknowledgment
This work was done within the FFG founded project Tomo3d (project number 845419).
References
[1] Sandra Mayr et al. Localization microscopy of actin cytoskeleton in human platelets. International Jour-
nal of Molecular Sciences 19.4 (2018).
[2] Andrey Aristov et al. ZOLA-3D allows flexible 3D localization microscopy over an adjustable axial
range. Nature Communications 9.1 (2018), p. 2409.
1Dipl. Ing. Fabian Hauser, University of Applied Sciences Upper Austria, School of Applied Health and Social Sciences,
Garnisonstr. 21, 4020 Linz, Austria, email: [email protected]. Ing. Dr. Jaroslaw Jacak, University of Applied Sciences Upper Austria, School of Applied Health and Social Sciences,
Garnisonstr. 21, 4020 Linz, Austria, email: [email protected]
21
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
EXPERIMENTAL INVESTIGATION AND SIMULATION OF 3D-PRINTED LATTICE
STRUCTURES
E. Heiml 1, A. Kalteis 2, Z. Major 3
Keywords: lattice structures, additive manufacturing, mechanical testing, finite element
analysis
Abstract
Lattice structures are currently of high interest especially for lightweight design. They generally have bet-
ter structural performance per weight than parts made of bulk material. With conventional manufacturing
techniques they are difficult to produce, but with additive manufacturing fabrication is quite easy. To better
understand their behaviour under various loading conditions two lattice structures in different configurations
were observed. For each structure three different test specimens were designed and manufactured using se-
lective laser sintering. To investigate the mechanical performance under large deformations the specimens
were made of a thermoplastic polyurethane, which shows a hyperelastic material behaviour. The diameter
of the trusses and the overall dimension of each structure were adapted, so that the volume fraction stayed
the same for each specimen. Beside the experimental observations also finite element simulations were con-
ducted. Therefore, the deformation behaviour of the structures could be investigated in more detail and the
results of the experiments and simulations could be compared.
1Eva Heiml, Institute of Polymer Product Engineering, Altenberger Straße 69, 4040 Linz, email: [email protected] Anna Kalteis, Institute of Polymer Product Engineering, Altenberger Straße 69, 4040 Linz, email: [email protected]. Dr. Zoltan Major, Institute of Polymer Product Engineering, Altenberger Straße 69, 4040 Linz,
email: [email protected]
22
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
COMBINED APPROACH OF TOPOLOGY AND PARAMETER OPTIMIZATION FOR
THE DESIGN OF LIGHTWEIGHT MULTICOPTER DRONES
F. Kiehas 1 , M. Reiter 2
Keywords: FEM-Simulation, parameter optimization, topology optimization, drone, multi-
copter, 3D-printing, injection moulding
Abstract
Due to the possibility of being completely electric driven, the ability for vertical take offs and simple rotor
mechanics for flight control, the most advantageous design for small-scale unmaned aircraft transportation is
the so called multicopter, a rotorcraft featuring more than two rotors.
To maximize the payload capacity and flight endurance, the vehicle has to be as light as possible while
still fullfilling the necessary strength and stiffness requirements. The optimization of the frame weight is im-
perative. A large potential for weight reduction is offered by utilization of modern materials like composites,
as well as modern manufacturing techniques such as 3D-printing.
Two seperate design studies for Quad- and Octocopters have been conducted. Based on preparatory topology
optimizations, general baseline design layouts for the frame structures have been developed. Various design
parameters have been defined to enable further parametric optimization of the geometry, with the objective of
minimizing part weight while being constrained to maintain sufficient strength levels. Correlations between
these parameters have been explored in a large number of finite element method simulations to get a better
understanding of which features offer the most potential for weight reduction.
1Dipl. Ing. Florian Kiehas, Institut fur Polymer Product Engineering, Johannes Kepler Universitat, Altenbergerstraße 69, 4040
Linz, email: [email protected]. Martin Reiter, Institut fur Polymer Product Engineering, Johannes Kepler Universitat, Altenbergerstraße 69, 4040 Linz,
email: [email protected]
23
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
MECHANO-BIOLOGICAL DEFORMATION RESPONSE OF MESENCHYMAL STEM
CELLS ADHERED TO POLYDIMETHYL-SILICONE MEMBRANES
B. Kronsteiner 1 , M. Pasztorek, E. Rossmanith, M.B. Fischer 2 , W. Baumgartner 3
Keywords: MSCs, PDMS functionalization, polydopamine, mechanical stretch
Abstract
To investigate the mechanobiological signaling of human amnion-derived mesenchymal stromal cells (hAM-
SCs) in response to tensile strength, cells were cultured on elastic polydimethylsiloxane (PDMS) surfaces.
Because of the inherent high hydrophobicity of PDMS surfaces, causing cells to dislodge from the surface,
chemical functionalization of PDMS surfaces with polydopamine (PD) was performed. PD proved to immo-
bilize collagen type 1 on PDMS membranes and thus, to stabilize the adherence of MSCs on the membrane
surface [1, 2]. In detail, in-house produced PDMS membranes were functionalized with polydopamine solu-
tion in different PD concentrations (0.01%w/v and 0.10%w/v) using different durations of functionalization
(1 h and 24 h). Additional coating of 20µg/ml collagen type1 (Diamed, Austria) was performed to investi-
gate the combinatorial effect of PD- and collagen-treated PDMS membrane surfaces on hAMSC adhesion [1].
hAMSC were cultured for 16 h on the PD-treated and collagen-coated PDMS surfaces; one group was me-
chanically stretched for 1 h and the other group remained un-stretched. To analyze the effect of stretching
to the MSC culture, carbon particles that served as orientation points for distance measurements before vs.
after stretching procedure were molded into the fluid PDMS membranes. After stretching procedure, both
groups were stained for actin, Live/Dead assessment and MSC surface marker CD90. hAMSC cultures were
then detached from the membranes enzymatically with accutase. Cell number, viability and actin stress fiber
formation were analyzed in both groups using flow cytometry and confocal microscopy.
Acknowledgment
The research has been supported by the European Regional Development Fund in frame of the projects
Kompetenzzentrum MechanoBiologie (ATCZ133) in the Interreg V-A Austria - Czech Republic programme.
References
[1] Kuddannaya, S. et al. Surface Chemical Modification of Poly(dimethylsiloxane) for the Enhanced Ad-
hesion and Proliferation of MSCs. ACS Appl. Mater. Interfaces 2013, 5: 9777–9784
[2] Chuah, Y. et al. Simple surface engineering of polydimethylsiloxane with polydopamine for stabilized
mesenchymal stem cell adhesion and multipotency. Sci. Rep. 2013, 5: 18162
1Bettina Kronsteiner, Faculty of Health Science and Biomedicine, Department for Biomedical Research, Danube University
Krems, Austria, email: [email protected] for Biomedical Research, Danube University Krems, Austria3Institute of Biomedical Mechatronics, Johannes Kepler University, Linz, Austria
24
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
STRAIN MEASUREMENT ON 2124-T851 ALUMINUM NOTCHED BAR SPECIMENS
BY DIGITAL IMAGE CORRELATION METHOD
M. Lutovinov 1 , J. Papuga 2 , J. Kuzelka 3
Keywords: DIC, load controlled, multiaxial loading, notch specimens, strain
Abstract
The strain response was measured by the Digital Image Correlation method on three types of notched spec-
imens made of 2124-T851 aluminum alloy. The types of the specimens were round bars with the U-notch,
V-notch and fillet notch. The experiments were load-controlled in tension-compression and torsion. Tested
loading paths include both proportional and non-proportional multiaxial paths.
The aim of the experimental program was to obtain the local strain response for verifying various notch
stress-strain approximate methods [1, 3]. Samples were loaded so that the yield strength in the notch was
exceeded. This ensured that the plasticization has occurred and the data include plastic strains. At least one
hundred cycles were measured by the Digital Image Correlation method in order to capture the potential
plastic softening effect.
Measured shear and axial strains are presented in the form of graphs. The differences in responses of the
three tested types of specimens are evaluated and the experimental measurement process is described.
Acknowledgment
This work was supported by the Grant Agency of the Czech Technical University in Prague, grant No.
SGS17/175/OHK2/3T/12.
References
[1] Lutovinov, M. et al. A comparison of methods for calculating notch tip strains and stresses under mul-
tiaxial loading. Frattura ed Integrita Strutturale 38, pp.237-243 (2016).
[2] Barkey, M.E.: Calculation of Notch Strains Under Multiaxial Nominal Loading. PhD Thesis, University
of Illinois at Urbana-Champaign, USA, 1993.
[3] Firat, M. A notch strain calculation of a notched specimen under axial-torsion loadings. Materials and
Design 32, pp.3876-3882 (2011).
1Dipl. Ing. Maxim Lutovinov, Czech Technical University in Prague, Technicka 4, 166 07 Prague 6,
email: [email protected]. Jan Papuga, Ph.D., Czech Technical University in Prague, Technicka 4, 166 07 Prague 6, email: [email protected]. Jirı Kuzelka, Ph.D., Czech Technical University in Prague, Technicka 4, 166 07 Prague 6, email: [email protected]
25
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
DEFORMATION RESPONSE OF POLYDIMETHYLSILOXANE SUBSTRATES
SUBJECTED TO UNIAXIAL QUASI-STATIC LOADING
F. Martino, V. Vinarsky 1 , J. Sleichrt, D. Kytyr 2
Keywords: compression loading, hyperelasticity, polydimethylsiloxane substrates
Abstract
To investigate cellular response of cardiomyocytes to substrate mechanics, biocompatible material with stiff-
ness in physiological range is needed. Polydimethylsiloxane (PDMS) based material Sylgard 184 is used for
construction of microfluidic organ on chip devices for cell culture due to ease of device preparation, bonding,
and possibility of surface functionalization. However it has stiffness orders of magnitude out of physiolog-
ical range. Therefore we adapted recently published protocol [1] aiming to prepare substrates which offer
stiffness in physiological range 5−100 kPa using various mixtures of Sylgard 527 and Sylagard 184. The in-
house developed loading device with the loading capacity of 3 kN with 1µm position tracking accuracy and
sub-micron position sensitivity was employed for this experimental campaign. The experiments were con-
trolled by the proprietary LinuxCNC software running on the real-time kernel [2]. All batches of the samples
were subjected to monotonic compression loading. During the displacement driven experiment with loading
rate 10µm · s−1 the samples with diameter 12.00 ± 0.05mm and height 14 − 16mm were compressed to
minimally 50% deformation. Because of high differences in the samples stiffness various load cells with
nominal capacity 50N, 10N, and 1N was used for the most reliable force logging. Material properties for
all batches were derived from a set of tests under dry and simulated physiological conditions. The results are
represented in the form of stress-strain curves calculated from the acquired force and displacement data and
elastic moduli are estimated as secant up to 10% deformation.
Acknowledgment
The research has been supported by the European Regional Development Fund in frame of the projects
Kompetenzzentrum MechanoBiologie (ATCZ133) in the Interreg V-A Austria - Czech Republic programme.
References
[1] Palchesko R.N. et al. Development of Polydimethylsiloxane Substrates with Tunable Elastic Modulus to
Study Cell Mechanobiology in Muscle and Nerve, PLoS ONE 2012, 7(12): e51499.
[2] Rada, V. et al. Multi-channel control system for in-situ laboratory loading devices, Acta Polytechnica
Proceedings CTU Proceedings 2018, 18: 15–19
1Fabiana Martino, Vladimır Vinarsky, International Clinical Research Center of St. Annes University Hospital Brno, Pekarka 53,
656 91 Brno, Czech Republic, email:{fabiana.martino,vladimir.vinarsky}@fnusa.cz2Jan Sleichrt, Daniel Kytyr, Institute of Theoretical and Applied Mechanics AS CR, v.v.i., Prosecka 76, 190 00 Prague 9, Czech
Republic, email: {sleichrt,kytyr}@itam.cas.cz
26
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
INVERSE COMPUTATIONAL DETERMINATION OF JOHNSON-COOK
PARAMETERS USING THE SHPB TEST APPARATUS
A. Mauko, B. Necemer, Z. Ren 1
Keywords: SHPB test apparatus, Johnson-Cook constitutive model, inverse determination,
Nelder-Mead optimization, computer simulations
Abstract
The Split Hopkinson Pressure Bar (hereinafter SHPB) test apparatus is used to determine the constitutive
material response at higher deformation rates between 102 s−1 and 8·104 s−1. The Johnson-Cook constitutive
model (hereinafter JC) is one of the most popular empirical material models that can be used for calculation of
the stress-strain relationship during high strain rate deformation also at elevated temperatures. The JC model
contains 5 material parameters that can be determined experimentally quite easily. The temperature material
softening was neglected in our study and the remaining 4 material constants were determined by the inverse
computational method [1]. First, a classic quasi-static tensile test of selected steel material was conducted,
followed by dynamic tests at two strain rates using the SHPB apparatus. A numerical model was built in the
LS-Dyna system to carry out the necessary simulations of the SHPB test [2]. The inverse determination of JC
parameters was done by comparing the measured and computed stress signals on input and output bars and
minimising their discrepancy by searching for appropriate parameters by applying the Nelder-Mead simplex
method [3]. The obtained JC material parameters much better describe the material behaviour at very high
strain rates in computational simulations if compared to the parameters derived by the classic procedure.
Acknowledgment
The authors acknowledge the financial support from the Slovenian Research Agency (research core funding
No. P2- 0063).
References
[1] Mauko, A.: Inverse computational determination of Johnson-Cook constitutive model parameters for
steel by using SHPB test apparatus, Master thesis, University of Maribor, Faculty of Mechanical Engi-
neering, 2018.
[2] Neemer, B.: Numerical modelling and validation of SHPB test apparatus, Master thesis, University of
Maribor, Faculty of Mechanical Engineering, 2017
[3] Nelder, J.A., Mead, R.: A Simplex Method for Function Minimization, The Computer Journal 7(4), pp.
308–313, 1965
1MSc. Anja Mauko, MSc. Branko Necemer, prof. Zoran Ren, University of Maribor, Faculty of Mechanical Engineering,
Smetanova ul. 17, 2000 Maribor, Slovenia, email: [email protected]
27
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
A PENDULUM ELECTROMAGNETIC ENERGY HARVESTER
M. Mistrulli 1 , D. Castagnetti 2
Keywords: energy harvesting, pendulum, T-structure, magnetic spring, electromagnetic
Abstract
Energy harvesters able to efficiently convert ambient energy into electrical energy allow the development of
self-sustainable electronic systems and remote sensors. Both piezoelectric or electromagnetic converters are
promising solutions and many examples can be found in the literature. This paper presents the design and
validation of an innovative double pendulum electromagnetic energy harvester including a magnetic spring.
Thanks to the magnetic spring, which stabilizes the pendulum with respect to its frame, the system can work
on whichever orientation, and, in addition, by calibrating the magnetic spring we easily obtain frequency
tuning of the converter. The system consists of a continuous T-structure, hinged in the intersection of the
arms: a coil is fixed on each end of the horizontal arms, while the magnetic spring is on the vertical arm.
The T-structure oscillates around the hinge as it receives an external dynamic excitation, consequently the
coils cross the magnetic field originated by a couple of permanent magnets fixed to the support frame. The
prototype, with a volume of about one cubic decimeter, was built and validated in two steps, using a dynamic
testing machine. First, we investigated the frequency response for different stiffness of the magnetic spring.
Second, we measured the output voltage and calculated the power output of the converter for three different
stiffness levels of the magnetic spring. The first results show that the resonant frequency of the system is in
the range between 2 Hz and 10 Hz and a power output up to about 2.5 mW, thus proving the validity of this
solution.
1Ing. Mistrulli Michele, Modena and Reggio Emilia University via Amendola 2, Reggio Emilia, email: [email protected]. Ing. Davide Castagnetti, Modena and Reggio Emilia University via Amendola 2, Reggio Emilia, email: da-
28
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
LIGHTWEIGHT AUXETIC METAMATERIALS DESIGNED THROUGH TRUSS
NETWORKS
L. Mizzi 1 , A. Spaggiari 2
Keywords: auxetics, metamaterials, Finite Element Analysis, 3D printing
Abstract
Auxetic metamaterials are a class of systems which exhibit the anomalous property of having a negative
Poissons ratio. This behaviour is primarily dependent on the geometry of the system rather than its inherent
material properties. One particularly well-known class of auxetic metamaterials is that of rotating unit sys-
tems which involve large rigid or semi-rigid blocks of material rotating relative to each other. In this work,
an attempt was made to design auxetic systems based on rotating unit mechanisms where the rotating unit
component of the system is made up of trusses rather than bulk material as is normally the case. Six well
known 2D auxetic geometries were studied, namely: rotating triangles, rotating quadrilaterals (squares, rect-
angles and parallelograms), anti-tetrachiral and hexachiral systems, and for each of these systems three forms
of truss configurations were investigated. The mechanical properties of these systems were compared with
those of the corresponding filled rotating unit structures using Finite Element Analysis and experimental tests
on 3D printed prototypes. The results obtained show that in cases where a triangular truss network is used to
build the rotating unit, the rigidity of the unit is retained and thus these systems possess similar mechanical
properties to their full rotating unit geometry equivalents, despite possessing a much lower overall material
volume.
1Luke Mizzi, Department of Sciences and Methods for Engineering, University of Modena and Reggio Emilia, Italy
email: [email protected] Spaggiari, Department of Sciences and Methods for Engineering, University of Modena and Reggio Emilia, Italy,
email: [email protected]
29
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
STRAIN RATE DEPENDENCY OF COMPRESSIVE BEHAVIOUR OF 3D PRINTED
SS316L BULK SPECIMENS WITH RESPECT TO PRINTING DIRECTION
M. Neuhauserova 1 , P. Koudelka, J. Falta, M. Adorna, T. Fıla, P. Zlamal
Keywords: 3D printing, stainless steel 316L, bulk, dynamic compression, quasi-static com-
pression
Abstract
The paper is focused on evaluation of the relation between mechanical properties of 3D printed material
(particularly stainless steel 316L) and printing direction (i.e. the orientation of the part which is being printed)
with respect to various strain rates during a compressive loading. The knowledge of these dependencies is
essential for calibration of material model used in numerical simulations, and thus for reliable prediction
of mechanical behaviour of 3D printed parts. In order to evaluate the strain rate dependency of the 3D
printed material’s compressive characteristics, dynamic and quasi-static experiments are performed. The
Split Hopkinson Pressure Bar (SHPB) is used for high strain rate experiments, which are performed at two
different strain rates. Quasi-static loading is performed using the Instron 3382 measuring device. Three
series of bulk specimens are produced using Renishaw AM250 printing device. Specimens from each of the
series have different printing orientation (vertical, horizontal and tilted - at an angle of 45 ◦ - with respect to
the powder bed). The specimens for high strain-rate experiments are dogbone-shaped and the specimens for
quasi-static loading have cylindrical shape. During both types of experiments the deformation of specimens
is observed using an optical setup. Custom developed Digital Image Correlation (DIC) tool [1] is used to
evaluate deformation of the specimens from the images captured during loading. Based on the measurements,
mechanical properties such as Young’s modulus, Poisson’s ratio, yield strength and compressive strength of
the 3D printed material are evaluated with respect to different printing orientations and strain rates.
Acknowledgment
The research was supported by the Czech Science Foundation (project no. 19-23675S) and the internal
grants of the Czech Technical University in Prague (projects no. SGS19/123/OHK2/2T/16). All the financial
support is gratefully acknowledged.
References
[1] Jandejsek, I. et al. Optimization and Calibration of Digital Image Correlation method. Experimentalni
analyza napeti 2010, 121-126, 2010
1Ing. Michaela Neuhauserova, Department of Mechanics and Materials, Faculty of Transportation Sciences, Czech Technical
University in Prague, Konviktskaa 20, 110 00 Prague 1, email: [email protected]
30
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
MECHANICAL AND STRUCTURAL PROPERTIES OF COLLAGEN NANOFRIBROUS
LAYERS UNDER SIMULATED BODY CONDITIONS
J. Rıhova 1 T. Suchy 2 L. Vistejnova 3 L. Horny 4 M. Supova 5
Keywords: collagen, fibroblasts, osteoblasts, mechanical properties, structural properties
Abstract
The main aim of this paper is the analysis of mechanical and structural properties of nanofibrous collagen
layers under conditions that simulate the body environment and in the presence of osteoblasts (bone cells) and
dermal fibroblasts (cells of connective tissues). Collagen layers were prepared by electrostatic spinning of
8wt.% collagen type I dispersion with 8wt.% (to collagen) of polyethylene oxide in phosphate buffer/ethanol
solution (1/1 vol) [1]. The stability of collagen nanolayers was enhanced by means of cross-linking with EDC
and NHS at a molar ratio of 1 : 4 . Prepared layers were exposed in cell culture medium containing 10% fetal
bovine serum for up to 21 days without or with human SAOS-2 human dermal fibroblasts or osteoblasts which
were cultured therein for up to 21 days. Cells were cultured in a standard culture medium that was used to
expose separate cell-free layers at 37 ◦C and 5% CO2. The proper seeding by both cell types was evaluated.
First, the cell culture on collagen nanolayers was assessed by fluorescence microscopy and determination
of metabolic activity. Second, the metabolic activity of both cell types grown on collagen nanolayers and
control (polystyrene surface) were measured after 1, 7, 14 and 21 days after the start of the experiment using
the Alamar Blue assay method. Mechanical properties (Young modulus and tensile strength) were determined
using the uniaxial tensile test. The influence of the cell activity on secondary structure of collagen nanofibrous
layers was verified by infrared spectroscopy. Furthermore, the influence of cells on given layers was evaluated
by electron spectroscopy.
References
[1] Suchy T. et al.: The release kinetics, antimicrobial activity and cytocompatibility of differently prepared
collagen/hydroxyapatite/vancomycin layers: Microstructure vs. Nanostructure, Eur. Pharma. Sci. 100
(2017).
1Ing. Jitka Rıhova Czech Technical University in Prague, Technicka 4, 166 07 Prague 6, email: [email protected]. Tomas Suchy, Ph.D.Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, Prague,
email: [email protected]. Lucie Vistejnova Biomedical Center, Medical Faculty in Pilsen, Charles University, Prague email: lu-
[email protected]. Ing. Lukas Horny, Ph.D.Czech Technical University in Prague, Technicka 4, 166 07 Prague 6,
email: [email protected]. Monika Supova, Ph.D. Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, Prague,
email: [email protected]
31
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
DESIGN AND VALIDATION OF A MINIMALLY INVASIVE ADJUSTABLE TITANIUM
PROSTHESIS AS A VERTEBRAL BODY REPLACEMENT
A. Sorrentino 1 , D. Castagnetti 2 , F. Taddei 3 , E. Schileo 4
Keywords: VBR, lumbar spinal recostruction, 3D printed implant, titanium structures
Abstract
Unstable vertebral body compression fractures, spinal tumors and post-traumatic deformities require a ver-
tebral body replacement (VBR). Usually, the reconstruction of the lumbar spinal column requires metallic
implants, also called cages, which are inserted after a total corpectomy in combination with an internal spinal
fixation device. These implants show several complications, including a low bone fusion rate, localized con-
tact between prosthetic endplates and vertebral endplate, and eventually overload the vertebral body due to
the excessive insertional force. Creation of a misalignment between prosthetic and bone endplate sometimes
causes the subsidence and collapse of the VBR [1]. Then, the ability of the prosthesis/bone interface to sup-
port vertebral loading is crucial to the successful implantation of these devices. Recently developed additive
manufacturing techniques (i.e. EBM) allow the production of trabecular titanium structures which provides
better biomechanics and customized solutions. Furthermore, most of vertebral body implants are currently
designed and produced in batches with standard dimensions, that are not able to meet the patient peculiar
features. This work aims to design, optimize and validate a new 3D printed trabecular titanium prosthesis
with adjustable height for lumbar VBR. The work focused on the durability of the implant considering the
lumbar spinal fatigue loadings acting on the porous cage, with the aims to improve bone ingrowth and, at the
same time, to minimize the effects of the surgical treatment on the sagittal alignment of the patient. In order
to achieve better performances in terms of spinal stabilization and fatigue life resistance, the design of this
new customized prosthesis takes into account the most critical factors of the vertebral body resection, with
the aim to ensure minimally invasive surgical procedure.
References
[1] A. Viswanathann et al, Initial experience with the use of an expandable titanium cage as a vertebral
body replacement in patients with tumors of the spinal column: a report of 95 patients, Eur. Spine J.,
vol. 21, n. 1, pagg. 8492, gen. 2012.
1M.Sc. Andrea Sorrentino, Department of Science and Methods for Engineering, University of Modena and Reggio Emilia, Via
Amendola 2, 42122, Reggio Emilia, Italy, email: [email protected]. Ph.D. Davide Castagnetti, Department of Science and Methods for Engineering, University of Modena and Reggio Emilia,
Via Amendola 2, 42122, Reggio Emilia, Italy, email: [email protected]. Ph.D. Fulvia Taddei, Bioengineering and Computing Laboratory, IRCCS Istituto Ortopedico Rizzoli, Via di Barbiano 1/10,
40126, Bologna, Italy, email: [email protected]. Ph.D. Enrico Schileo, Bioengineering and Computing Laboratory, IRCCS Istituto Ortopedico Rizzoli, Via di Barbiano
1/10, 40126, Bologna, Italy, email: [email protected]
32
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
DEVELOPMENT OF AN INJECTION MOULDING SIMULATION ALGORITHM TO
CONSIDER THE EFFECT OF SEGREGATION DURING INJECTION MOULDING
T. Temesi 1 F. Szabo 2
Keywords: numerical simulation, injection moulding, additives
Abstract
Injection moulding is one of the most versatile and dynamically evolving polymer forming processes. With
injection moulding, three-dimensional polymer parts with complex geometry can be manufactured with vir-
tually zero waste output. As a result of the inherent properties of the injection moulding technology, every
part needs its unique mould, and a careful optimization of the process and technological parameters is also
necessary. Numerical simulation methods are increasingly used to support and ease the design of the moulds
and the manufacturing process itself. The amount of time, energy and cost that can be saved using these
methods depend on the algorithms precision in approximating certain properties of the material and the poly-
mer part during the injection moulding process. Todays algorithms apply numerous simplifying conditions
in the simulation because the behaviour of the polymer material is quite complex during the manufacturing
process. One of the most basic simplification is that no irreversible change happens in the materials structure
during the simulation. However, during the injection moulding of polymers filled with additives, a so-called
segregation effect occurs, depending on the size of the additives and technological parameters. This means
that the distribution of the additive is uneven in the injection moulded part: certain areas are enriched, while
in other areas, the concentration of the additive is decreased. This effect leads to different amounts of shrink-
age in the moulded part, which can not be predicted with current simulation algorithms [1, 2].
Our aim is to develop models and methods, in which the effect of inhomogeneities in the polymer mate-
rial is considered, leading to a better approximation of real-world processes in the numerical modelling and
simulation of the injection moulding process [3].
Acknowledgment
This paper was supported by the Jnos Bolyai Research Scholarship of the Hungarian Academy of Sciences
and by the NKP-18-4 New National Excellence Program of the Ministry of Human Capacities.
The authors wish to thank Arburg Hungaria Kft. for the Arburg Allrounder 370S 700-290 injection molding
machine, Lenzkes GmbH for the clamping tool system, and Piovan Hungary Kft. for their support.
References
[1] Huamin, Z.: Computer Modeling for Injection Molding: Simulation, Optimization, and Control. John
Wiley and Sons, Inc., Hoboken, New Jersey, USA, 2013.
1Tamas Temesi, PhD student, Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of
Technology and Economics, Muegyetem rakpart 3, Budapest, H-1111, Hungary, email: [email protected] Szabo, PhD, Assistant Professor, Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest
University of Technology and Economics, Muegyetem rakpart 3, Budapest, H-1111, Hungary, email: [email protected]
33
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
[2] Rhodes, M.: Introduction to Particle Technology. John Wiley and Sons, Ltd., London, UK, 2008.
[3] Kovcs, J.G.: Shrinkage Alteration Induced by Segregation of Glass Beads in Injection Molded PA6:
Experimental Analysis and Modeling. Polymer Engineering and Science, 51(12), p. 2517-2525, 2011.
34
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
WIND TUNNEL TESTS FOR LIFETIME ESTIMATION OF BRIDGE AND MAST
CABLES EXPOSED TO VORTEX INDUCED VIBRATIONS
A.Trush 1 , S.Pospısil 2 , S. Kuznetsov 3
Keywords: bridge cable, wind tunnel, vortex shedding
Abstract
A significant number of TV and radio broadcasting masts in the Czech Republic was built in the 70-80s of
the last century. At the moment is an actual issue is the reconstruction and determination of residual life
of these structures. Guyed masts and particularly guy ropes have significant dimensions and comparatively
low mass and damping with high flexibility. Therefore, aerodynamic and aeroelastic loads, such as vortex
induced vibrations, galloping, wind gusts, etc., see [1], are key for them. As a tensile construction elements
(guy ropes) for guyed masts the traditional open wire spiral strand cables are used. This type of cable has
a characteristic helical surface roughness pattern that can act as vortex suppressor, high fatigue endurance,
although somewhat lower corrosion resistance comparing to modern locked coil cables with non-circular
shaped wires of outer layer and cables with protective polymer coatings. At the same time, on numerous
bridges with the above-mentioned modern cable types the fatigue damage to wires in anchorage zones and
destruction of protective coatings was detected, see [2]. Present paper provides results of wind tunnel test-
ing of three models of helical strake cable in order to evaluate separately impact of lay angle and surface
roughness factors and reference smooth cylinder model in flow with grid generated turbulence of different
intensities. The reduction of the lock-in range of helical strand cables comparing to reference smooth model
was observed whereby the greatest impact was an increase of lay angle.
Acknowledgment
The activity presented in the paper is part of the research grant No. 19-04695S of the Czech Science Foun-
dation (GAR).
References
[1] Zdravkovich, M.M.: Flow around circular cylinders. Vol. 1: Fundamentals. Oxford University Press,
USA, 1997.
[2] Siegert, D. and Brevet, P. Fatigue of stay cables inside end fittings high frequencies of wind induced
vibrations. OIPEEC Bulletin 89, S43-S51 (2005).
1Mgr. Arsenii Trush, Institute of Theoretical and Applied Mechanics AS CR, v.v.i., Prosecka 76, 190 00 Prague and Czech
Technical University, Thakurova 7, 160 00 Prague, Czech Republic, email: [email protected]. Ing. S.Pospısil, Ph.D., Institute of Theoretical and Applied Mechanics AS CR, v.v.i., Prosecka 76, 190 00 Prague, Czech
Republic, email: [email protected]. Ing. S. Kuznetsov, Dr.Sc., Institute of Theoretical and Applied Mechanics AS CR, v.v.i., Prosecka 76, 190 00 Prague,
Czech Republic, email: [email protected]
35
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
FEASIBILITY STUDY: MULTIPHOTONLITHOGRAPHY
M. Wimmer 1
Keywords: multiphoton lithography, additive manufacturing
Abstract
The thesis describes the possibilities of additive manufacturing with multiphoton lithography.
The basis of this technology is, that a mixture of a liquid monomer and photo-initiator can be forced to
start a polymerization by emitting a laser of a certain wave length into the fluid. The power of the laser cracks
the photo-initiator and starts a radical polymerisation.
This study focuses on the influences during the manufacturing process. One of the important aspects is
the choice of the solvent for the post processing. In sequence to the solvent problem, the influence of the
layer height is examined. With the data gathered from those experiments the main objectives of the study
was, to build a cube with the maximum possible side length in 12 hours. Furthermore the limits and possibil-
ities of the setup in use were investigated. As an example the differences in fabrication with the laser firing
with constant frequency and constant density were subject of this investigation.
The second goal of the study was to compare three different structures consisting of periodically repeating
elements, scaled in size and number of elements per side.
1Markus Wimmer, Institute of Polymer Product Engineering, Altenbergerstraße 69, 4040 Linz,
email:[email protected]
36
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
SIMULATION AND OPTIMIZATION OF POROUS BONE-LIKE MICROSTRUCTURES
WITH SPECIFIC MECHANICAL PROPERTIES
A. Wit, S. Wronski, J. Tarasiuk 1
Keywords: Bone modeling, Voronoi tessellation, porous structure
Abstract
Bone is a complex structure made of stiff mineral scaffold and soft tissue filling their internal pores. The
various geometry and heterogeneity of bone beams give the bone special mechanical properties. Bone can be
characterized as a connected network of bars or plates with specific organization depending on where they
are in the bones. However, the geometry of the bone beams and their spatial arrangement are not random.
The structure of the trabecular bone (meso scale) is adapted to the values of stresses and strains affecting
the skeletal system. In order to build a correct numerical model of bone tissue, it is necessary to know what
is the structure and function of the bones in the human body. Many studies discuss the problem of porous
structures but only a few connect their geometric properties with mechanical characteristics [1]. To simulate
bone structure we propose stochastic structure based on hyperuniform spatial points distribution connected
by the combination of Voronoi tessellation and Delaunay triangulation. The synergy of this two method
allow us to create more natural and smooth scaffold configurations. We are specially aware of features
that mostly influence mechanical stiffness: porosity, connectivity and anisotropy. Numerical methods of
analyzing, generating, and optimizing structure seems to be promising method to obtain the structure with
most similar values to the real bone. Additionally the generator is characterized by good repability in the
satisfactory minimal size of structures. Results of simulations strongly depend on initial model parameters
and the type of simulations. Developed methods of simulation and optimization lead to better bone substitutes
which will enable correct adaptation when using as bone implants.
Acknowledgment
This work was financed by the Polish National Centre for Science (NCN) under decision number:
2017/26/E/ST5/00043. Adrian Wit has been partly supported by the EU Project POWR.03.02.00-00-I004/16.
References
[1] S. Munoz S. et al. Different models for simulation of mechanical behaviour of porous materials, Journal
of the Mechanical Behavior of Biomedical Materials 2018, 80, 88–96.
1B.Eng. Adrian Wit, Dr hab. Sebastian Wronski, Dr hab. Jacek Tarasiuk, Faculty of Physics and Applied Computer Science,
AGH, al. Mickiewicza 30, 30-059 Krakow, Poland, email: {adrian.wit,wronski,tarasiuk}@fis.agh.edu.pl
37
Index
Adorna, M., 8, 15, 29
Ascari, F., 9
Avalle, M., 17
Barone, C., 9
Baumgartner, W., 23
Bergonzi, L., 17
Castagnetti, D., 9, 27, 31
Concas, F., 11
Csiszer, T., 10
Diebels, S., 11, 16
Doktor, T., 12
Dragoni, E., 9
Dudek, K. K., 13
Dvorak, R., 14
Furst, D., 19
Fıla, T., 8, 12, 14, 15, 19, 29
Falta, J., 8, 15, 29
Fischer, M. B., 23
Fissore, L., 16
Frascio, M., 17
Glinz, J., 19
Hauser, F., 20
Heiml, E., 21
Horny, L., 30
Jacak, J., 20
Jirousek, O., 12
Jung, A., 11
Kalteis, A., 21
Kastner, J., 19
Kiehas, F., 22
Koudelka, P., 12, 14, 29
Kronsteiner, B., 23
Kuzelka, J., 24
Kuznetsov, S., 34
Kytyr, D., 12, 19, 25
Lutovinov, M., 24
Major, Z., 21
Martino, F., 25
Mauko, A., 26
Mistrulli, M., 27
Mizzi, L., 28
Molnar, L., 10
Monica, F., 9
Monti, M., 17
Moroni, F., 17
Necemer, B., 26
Neuhauserova, M., 29
Papuga, J., 24
Pasztorek, M., 23
Perrone, A., 9
Pirondi, A., 17
Pospısil, S., 34
Reiter, M., 22
Ren, Z., 26
Rossmanith, E., 23
Rıhova, J., 30
Schileo, E., 31
Schrempf, A., 19
Senck, S., 19
Sorrentino, A., 31
Spaggiari, A., 9, 28
Suchy, T., 30
Szabo, L., 32
Sleichrt, J., 19, 25
Supova, M., 30
Taddei, F., 31
Tarasiuk, J., 36
Temesi, T., 10, 32, 34
Vettori, M., 17
Vistejnova, L., 30
Vinarsky, V., 25
Wimmer, M., 35
Wit, A., 36
Wronski, S., 36
Zlamal, P., 8, 12, 15, 29
38
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
39
YSESM 2019, June 6th – June 8th, Telc, Czech Republic
40