9th Conference on Industrial Computed Tomography, Padova, Italy (iCT 2019)

Virtual material characterization of composite materials in Simcenter 3D:micro-CT-based voxel approach for stiffness homogenization

Oxana Shishkina1, Anna Matveeva1, Martine Wevers2, Stepan V. Lomov2, Laszlo Farkas1

1Siemens Industry Software NV, Interleuvenlaan 68, 3001 Leuven, Belgium, e-mail: oxana.shishkina@siemens.com2KU Leuven, Department of Materials Engineering (MTM), Kasteelpark Arenberg 44, 3001 Leuven, Belgium

AbstractWhile the aerospace, transportation, and energy applications are still driving the growth of the composites market, the use ofcomposite materials has also become widespread in people’s daily lives. Nowadays, these materials can be found inelectronics and appliances, sport, leisure, and recreation goods thanks to their lightweight benefits and multiple designoptions. The usual composites design process is an iterative hybrid test-simulation process [1] in which numerical modelsare built on the results of an extensive experimental campaign for the material database generation to cover critical designaspects. Such a process is test-intensive, time-consuming and not economical. Therefore, engineers shift to more efficientvirtual product development. This concept is driving the development of Simcenter 3D Virtual Material Characterization(VMC) ToolKit by Siemens PLM Software towards a complete and efficient multi-scale simulation process. The vision forthis approach is allowing the engineers material exploration and efficient translation of design requirements to materialrequirements in early design stages [2, 3].Composite materials can be modeled in numerous ways which differ in the level of structural details and realism. Oftenmodeling techniques use so-called “idealized” (simplified) geometry of composites (unit cells), which can be created in aparametric manner using available software, for example, WiseTex (KU Leuven, Belgium) or TexGen (University ofNottingham, UK) [4, 5]. However, real composites never have an ideal structure but are subjected to multi-scale geometricalvariability introduced by the different phases of the manufacturing process [6].Micro-computed tomography (micro-CT) imaging technique shows a great potential to visualize real composite structureby acquiring a set of high-resolution radiographs using X-rays and after, reconstructing a three-dimensional (3D) image ofthe studied composite using data processing algorithms. As an alternative to the idealized, parametric models, a voxel-basedapproach [7, 8] was developed for a direct conversion (segmentation) of 3D micro-CT images of real composites into rich-in-details voxel models, which resulted in the creation of VoxTex software by the Department of Materials Engineering(MTM), KU Leuven [9]. After the image segmentation and orientation analysis, voxel models can be transformed into finiteelement (FE) models to perform mechanical computations. The strong ability to determine the overall elastic properties ofcomposites with voxel models were validated, for example, in [4, 10]. The Simcenter 3D VMC ToolKit does not only allowthe creation of idealized models of composites [2] but was extended towards the voxel-based approach by developingVirtualCT tool interfacing with the VoxTex software. The current work demonstrates the potential of the Simcenter 3D VMCToolKit for stiffness homogenization for composite materials starting from their micro-CT images (see also [11, 12]).

Keywords: composites, voxel models, finite element homogenization, automation, multi-scale modeling

References[1] M. Bruyneel, J.-P. Delsemme, P. Jetteur, C. Lequesne, B. Magneville, L. Soppelsa, S. McDougall, T. Naito, Y. Urushiyama, Damage analysis oflaminated composites with SAMCEF: Validation on industrial applications, in Proceedings of the 30th Technical Conference of the American Societyfor Composites, Michigan State University, USA (2015) 1-12, https://orbi.uliege.be/handle/2268/184956.[2] L. Farkas, K. Vanclooster, H. Erdelyi, R.D.B. Sevenois, S.V. Lomov, T. Naito, Y. Urushiyama, W. Van Paepegem, Virtual materialcharacterization process for composite materials: an industrial solution, in Proceedings of the 17th European Conference on Composite Materials(ECCM-17), Munich, Germany, (2016) 1-6.[3] A. Matveeva, D. Garoz, R. Sevenois, M. Zhu, L. Pyl, W. Van Paepegem, L. Farkas, Effect of intra-ply voids on the homogenized behavior of aply in multidirectional laminates, IOP Conference Series: Materials Science and Engineering, 406 (2018) 012009.[4] N. Isart, B. El Said, D.S. Ivanov, S.R. Hallett, J.A. Mayugo, N. Blanco, Internal geometric modelling of 3D woven composites: A comparisonbetween different approaches, Compos. Struct. 132 (2015) 1219-1230.[5] S.V. Lomov, Modelling the geometry of textile reinforcements for composites: WiseTex, in: P. Boisse (Ed.), Composite Reinforcements forOptimum Performance, Elsevier, 2011, pp. 200-238.[6] A. Vanaerschot, F. Panerai, A. Cassell, S.V. Lomov, D. Vandepitte, N.N. Mansour, Stochastic characterisation methodology for 3-D textilesbased on micro-tomography, Compos. Struct. 173 (2017) 44-52.[7] Y. Liu, I. Straumit, D. Vasiukov, S.V. Lomov, S. Panier, Prediction of linear and non-linear behavior of 3D woven composite using mesoscopicvoxel models reconstructed from X-Ray micro-tomography, Compos. Struct. 179 (2017) 568-579.[8] I. Straumit, S.V. Lomov, M. Wevers, Quantification of the internal structure and automatic generation of voxel models of textile compositesfrom X-ray computed tomography data, Compos. A, Appl. Sci. Manuf. 69 (2015) 150-158.[9] Department of Materials Engineering, KU Leuven, Quantification of μCT images of textile composites: VoxTex software.https://www.mtm.kuleuven.be/Onderzoek/Composites/comptest2017/Day3_Session1_3_Lomov, 2017 (accessed 09 November 2018).[10] I. Straumit, Prediction of the effective properties of textile composites based on X-Ray computed tomography data, PhD thesis, KU Leuven,2017.[11] O. Shishkina, A. Matveeva, S. Wiedemann, K. Hoehne, M. Wevers, S. V. Lomov, L. Farkas. X-Ray computed tomography-based FE-homogenization of sheared organo sheets, in Proceedings of the 18th European Conference on Composite Materials (ECCM-18), Athens, Greece,(2018) 1-8.[12] S. Nikolaev, K. Vanclooster, O. Shishkina, L. Farkas, S.V. Lomov, Mechanical properties identification of a woven carbon fiber-reinforcedcomposite in Simcenter, The 2018 Simcenter Conference – Europe, Prague, Czech Republic, (2018)

Siemens PLM Software

Virtual material characterization of composite materials in Simcenter 3D:micro-CT-based voxel approach for stiffness homogenizationOxana Shishkina1, Anna Matveeva1, Martine Wevers2, Stepan V. Lomov2, Laszlo Farkas1

1 Siemens Industry Software NV, Leuven (Belgium) , 2 Department of Materials Engineering (MTM), KU Leuven, Leuven (Belgium)

IntroductionNowadays, engineers shift from test-intensive time-consuming development processtowards a more efficient virtual product development by application of advanced finiteelement (FE) modelling techniques. Relaxation on the test effort is possible by theapplication of multi-scale modelling concept [1]. Staying at continuum scales, thisconcept relies on the detailed material modelling that goes down to the micro-scale (orfiber-level) and sequentially builds material mechanical behavior knowledge toward themeso- (or yarn/bundle-) and macro-(or application)-scales.

References[1] L. Farkas, K. Vanclooster, H. Erdelyi, R. Sevenois, S.V. Lomov, T. Naito, Y. Urushiyama, W. Van Paepegem, Virtual material characterization process for composite materials: an industrialsolution, 17th European Conference on Composite Materials (ECCM17), Munich, Germany (2016) 1-6.[2] I. Verpoest, S.V. Lomov, Virtual textile composites software WiseTex: Integration with micro-mechanical, permeability and structural analysis, Composites Science and Technology 65(15–16)(2005) 2563-2574.[3] S.V. Lomov, D.S. Ivanov, I. Verpoest, M. Zako, T. Kurashiki, H. Nakai, S. Hirosawa, Meso-FE modelling of textile composites: Road map, data flow and algorithms, Composites Science andTechnology 67(9) (2007) 1870-1891.[4] S.V. Lomov, Webpage of WiseTex suite, 2017. https://www.mtm.kuleuven.be/Onderzoek/Composites/software/wisetex.[5] P. Ladeveze, E. LeDantec. Damage modelling of the elementary ply for laminated composites. Composites Science and Technology 43 (1992) 257-267.[6] I. Straumit, S.V. Lomov, M. Wevers. Quantification of the internal structure and automatic generation of voxel models of textile composites from X-ray computed tomography data.Composites Part A, 54 (2015) 150-158. // see also: https://www.mtm.kuleuven.be/Onderzoek/Composites/comptest2017/Day3_Session1_3_Lomov[7] O. Shishkina, A. Matveeva, S. Wiedemann, K. Hoehne, M. Wevers, S. V. Lomov, L. Farkas. X-Ray computed tomography-based FE-homogenization of sheared organo sheets, in Proceedings ofthe 18th European Conference on Composite Materials (ECCM-18), Athens, Greece (2018) 1-8.[8] S. Nikolaev, K. Vanclooster, O. Shishkina, L. Farkas, S.V. Lomov, Mechanical properties identification of a woven carbon fiber-reinforced composite in Simcenter, The 2018 SimcenterConference – Europe, Prague, Czech Republic (2018).

VirtualCT tool modelling workflow: from micro-CT imagesto homogenized material stiffness

Figure 3: VirtualCT for Simcenter 3D VMC ToolKit: workflow by example of a laminatemanufactured from a 30˚-sheared woven organo sheet [7].

Contact information:

Dr. Oxana Shishkina oxana.shishkina@siemens.com

Acknowledgements:

The authors gratefully acknowledge SIM (Strategic Initiative Materials in Flanders) and VLAIO (the Agency Flanders Innovation &Entrepreneurship) for their support of the ICON project M3Strength (Grant no.140158) which fits in the research programMacroModelMat (M3) coordinated by Siemens (Siemens PLM Software, Belgium). O. Shishkina thanks VLAIO for financing her workin the framework of the Innovation Mandate Project “Micro-CT-based Model Generation Engine for Virtual MaterialCharacterisation” (Grant no. HBC.2017.0189). S.V. Lomov holds Toray Chair for Composite Materials at KU Leuven, the support fromwhich is also acknowledged.

Virtual Material Characterization (VMC) ToolKitThe above introduced concepts are driving the development of the VMC ToolKit bySiemens PLM Software (Fig. 1) towards a complete and efficient multi-scale simulationprocess for materials engineering. The vision for this approach is to allow engineersmaterial exploration and efficient translation of design requirements to materialrequirements in early design stages.

Figure 1: Simcenter 3D and VMC ToolKit covering hierarchical multi-scale and multi-physicsmodelling of composites.

VMC ToolKit FunctionalitiesThe results below have been achieved in collaboration with KU Leuven and UGent as part of the SIM M3Program, “M3Strength” ICON project (see acknowledgements for details).

ü Micro/meso-scale geometry engine: random packing including voids or interfacingwith WiseTex by KU Leuven for textile composites [2, 3].

ü Analytical homogenization at the micro- (Chamis formulae) and meso-scales(integration of TexComp by KU Leuven [4]).

ü Streamlined meshing process: dealing with different material phases and the interfacemesh (cohesive zone).

ü Local material definition considers yarn crimp and changes in volume fraction.ü Automatic definition of loading and constraints including periodic BC.ü Virtual identification of the elastic constants and complete set of damage-plasticity

parameters for the LMT-Cachan (Ladevèze) damage model [5].ü Material data management enabling material traceability.ü Micro-CT-based voxel meshes of realistic composite geometry (VirtualCT tool) via

the interface with VoxTex by KU Leuven (Fig. 2) [6]. Resulting realistic models canaccount for material variability and can be exploited in the context of additionalphysical attributes.

(left) (right)Figure 4: Results of the study cases performed with Simcenter 3D VMC ToolKit for: (left)organo sheets [7], (right) woven carbon fiber/epoxy composite [8].

Study cases1. Virtual assessment of the effect of shear on the homogenized elastic properties of thethermoplastic woven organo sheet composites [7]

Five thermoplastic woven glass roving-PA6 organo sheet laminates were sheared tovarious angles: 15˚, 30˚, 45˚ and 60˚ in the hot state and, then, consolidated. Theirhomogenized elastic properties were obtained following the workflow in Fig. 3 andcompared with the results of tensile tests. VirtualCT tool of Simcenter 3D VMC ToolKitallowed a high-fidelity micro-CT-based reconstruction of the analyzed laminates. Themoduli predicted using VMC ToolKit showed being in a good agreement with theexperiments (Fig. 4, left).

2. Comparison of numerical and experimental techniques towards the prediction of theelastic properties of a woven carbon fiber-reinforced epoxy composite [8]

A woven carbon fiber/epoxy plate was tested under tension and investigated by meansof modal analysis to obtain reference values of the Young's modulus. In parallel, avirtual assessment of the composite elastic constants was done using Simcenter 3DVMC ToolKit, which included• generation of an “idealized” unit cell in WiseTex and solving it analytically for

stiffness in TexComp (Mori-Tanaka scheme) and also performing FEA;• micro-CT images acquisition of a “real” composite and following the VirtualCT

modelling workflow for the stiffness prediction (Fig. 3).The study showed that voxel models built with VirtualCT tool predicted accurate elasticmoduli compared to the experimentally measured values (Fig. 4, right).

Figure 2: Micro-CT image analysis with VoxTex: (from left to right) voxel model, localorientations, volume segmentation into material components [6].

VoxTex (by Department MTM, KU Leuven)is a micro-CT data analysis software aimed at converting micro-CT images of textilecomposites into FE models to perform mechanical computations (calculation ofhomogenized stiffness, permeability) and allowing to perform fiber orientationdistributions analysis, fiber and yarn misalignment analysis, assessment of volumetricfractions of components (matrix, reinforcement, voids).