Title

Progressive failure of woven polymer-based composites under dynamic loading; Theory and analytical simulation

Date of Completion

January 2008

Keywords

Engineering, Aerospace|Engineering, Mechanical|Engineering, Materials Science

Degree

Ph.D.

Abstract

Woven polymer-based composites are currently used in a wide range of naval applications. Use of composite materials in critical applications requires that dynamic material behavior be fully characterized. Composite material behavior is generally well understood in the linear regime, and can be predicted with sufficient confidence up to the point of first ply failure. However, the mechanical behavior beyond first ply failure is not characterized by a validated theory that can account for material nonlinearity, strain rate dependence, and progressive failure. The objective of this work is to develop and validate a progressive failure approach that can be used for woven polymer-based composites subjected to dynamic loads. The theory is implemented in a commercial finite element program with a user material subroutine that defines the constitutive theory and implements the progressive failure methodology. A deformation based failure criterion, intended for large strain analysis of woven composites, is also proposed. The progressive failure approach is validated using basic tension and open hole tension tests. The tests are performed using digital image correlation, which provides the complete non-uniform strain and displacement fields. The simulation results are in good agreement with experimental data. ^