Fiber-Reinforced Polymeric Material Systems: A Multi-Scale, Elasto-Viscoplastic Homogenization Approach

University Of Pennsylvania, Philadelphia PA

Investigators

Abstract

This project addresses multi-scale homogenization (averaging) techniques for fiber-reinforced polymer systems, including long-fiber reinforced polymers, and thermoplastic elastomers with cylindrical structures. The goal is to develop general and computationally efficient constitutive models that are capable of handling coupled elasto-visco-plastic behavior and the effect of microstructure--and its evolution--at two different length scales. The possible development of macroscopic and microscopic instabilities will also be investigated. The techniques to be developed in this work will be of broad application to large classes of polymeric, metallic, biological and geological material systems, and will lend themselves to numerical implementation in constitutive subroutines for use with standard finite element method packages. Once fully developed, they will replace current models based on linear-elastic analyses, requiring the use of large safety factors in industrial applications. This project includes two international collaborations, one with Pierre Suquet (CNRS, Marseilles) and the other with Javier Llorca (IMDEA, Madrid), on complementary aspects of the proposed work. They will allow the students involved in this project to acquire valuable international experience through participation in multi-country, multi-laboratory collaborative projects. The principal investigator will teach a course on Homogenization Methods, and is also writing a book that is based on this course, which aims to make the recent progress in nonlinear homogenization available to a larger audience. Improvements in the modeling and performance of long-fiber-reinforced polymers should lead to significant energy savings in the aerospace and other industries, while better understanding of thermoplastic elastomers is highly desirable because of their recyclable properties, and consequent positive implications for the environment.