报告时间：2019年11月6日，下午14:00-15:30
报告地点：航空楼A706
邀 请 人：黄玮副教授 马玉娥教授
报告题目：
Deformation and failure behaviours of injection molded short glass fiber reinforced composites
报告人简介：
Dr. Liu Ping is a Senior Scientist in Engineering Mechanics Department in Institute of High Performance Computing, A-Star, Singapore. Her research interests focus on computational solid mechanics, composite Materials and thermal analysis. She has done extensive work on the modeling and simulation of nanostructures, microstructures and macrostructures. She has been published numerous high quality journal papers and involved in various industrial projects as PIs.
报告内容：
Short fiber reinforced composites are receiving more research efforts and more applications due to advantages including high strength- and modulus-to-weight ratios, fast processing rate and relatively low manufacturing cost. Injection molding which is fast and allows the production of composite parts with complex geometries is a commonly used technique to produce short fiber reinforced composites. The properties of short fiber reinforced composites depend on the fiber volume fraction, fiber orientation distribution and fiber length distribution. Composites produced by injection molding have complex fiber orientation and length distribution. The stress transfer in short fiber composites is a very complex problem which involves elastic stress transfer between matrix and fiber, matrix yielding, matrix cracking, interfacial debonding, plastic stress transfer, fiber pull-out and fiber fragmentation. Computational models which are able to consider such complex fiber orientation and length distribution will be useful tools for the design of short fiber composites. In this study, a finite element analysis (FEA) platform which is capable of considering both preferential alignment and non-uniform length distributions of short fibers in injection molded composites was proposed. The preferential alignment of short fibers is represented by a preferential angle. An in-house FORTRAN code was developed to implement the preferential angle and non-uniform fiber length distribution. The effects of fiber volume fraction, fiber length and fiber orientation on the mechanical properties of glass fiber composites were studied using the developed FEA platform. Preferential orientations of glass fibers at different fiber loading were identified through FEA simulations. A damage model was developed to account for the interfacial damage. When real fiber length distribution, fiber preferential orientation and interface damage model are incorporated, good agreement between simulations and experiments was achieved. Equations for fiber length efficiency factor and fiber orientation efficiency factor were derived based on FEA results. These equations would finally allow the calculation of the Young’s modulus and tensile strength of injection molded short fiber composites.
