MOTIVATION: Scientific and engineering insights together are crucial tor being at the cutting edge that has not only scientific value, but also immediate applicability and added value for the society. This requires communicating efforts and output from both basic science and engineering and the challenge is to establish a communication or network of knowledge gathered somewhat independently at different scales (of time and length). Such a challenge asks for a strong teamwork, skills, expertise and insight from the molecular dynamics simulations to finite element based structural optimization.

1 A° 1 nm 10 nm 100 nm 1 m 10 m 1 mm

C-C bond length≈1.54 A °

Tool/topic#1: Molecular Dynamics (MD) simulations: investigation of the molecular interactions among the constituents of composites: their signature on mechanical properties

Carbon nanotubes (CNT) ≈ 1- 10 nm

Tool/topic#2: Incorporation of a coarse grain method dissipative particle dynamics (DPD) along with the MD: Carbon nanotube (CNT) dispersion in polymer solutions.

CNT/polymer composite nanofiber

Tool/topic#3: Electrospinning of CNT/polymer composite nanofibers: process optimization

Tool/topic#4 Nanofibrous interlayers for laminated composites

Tool/topic#5: Micromechanics based failure criteria for polymeric composites and incorportion into design

Tool/topic#6: Meso-scale effects of reinforcing textiles in composites

20 m

Tool/topic#7: Design, manufacture and testing of structural composites

ADVANCED COMPOSITES & POLYMER PROCESSING LAB

MULTI-SCALE ENGINEERING OF COMPOSITES

Kaan Bilge (PhD) Ayça Ürkmez (MSc)

Dr. Elif Özden Yenigün Assoc. Prof. Melih Papila

Prof. Yusuf Menceloğlu Prof. Ali Rana Atılgan

Prof. Canan Atılgan

APPLICATION FIELDS Aerospace Marine Automotive Energy Construction Sporting goods

COLLABORATORS Roketsan Telateks/METYX Composites Boğaziçi University Middle East Technical University Stanford University San Diego State University

FUNDING

Significance Two “non-crimp” fiber orientations within a standard single ply thickness. Can form hybrid reinforcement

Objective To explore unconventional high performance structural composites and design: simultaneous weight and cost reduction

Approach

Results

Bi-angle Thin-ply Non-crimp Fabric (NCF) Composites

Why Bi-angle? Why Thin-ply? Why NCF?

Simpler building block

Tougher laminate Mass producible

Anisotropy Improved quality Shallow angle

No micro crack Less delamination Handling

Asymmetry Homogenization 1-axis layup

Homogenized laminates

Significance Electrospun fibrous mats offer: -effective planar distribution of the nanoscale fibers and the fillers - layer-by-layer integration - no weight penalty

Objective To integrate nano-scale fibrous non-woven mats into structural composites for enhanced mechanical properties and performance

Approach Electrospinning: -produces layers of nano-scale polymeric fibers with tailored chemical compatibility -allows nano-scale fillers such as CNTs to be readily embedded into the polymeric fibers

Results

Nano-engineered Composites: Structural Composites

Hybridized with Polymer/MWCNT Nanofibrous Interlayers

100˚C 25˚C

Test Type % change

GIIC +50

strength +20

Flex. modulus +30

Charpy +20