Orthotropic damage model for composite structures using the 3D Tsai-Wu failure criterion

This paper presents a novel approach concerning the development of an orthotropic damage model based on the original 3D Tsai-Wu failure criterion. In its original formulation, the Tsai-Wu criterion is only capable of identifying the existence of damage at a certain point in the material. However, it is not capable of identifying if the damage is located in the fiber, matrix or interlaminar zone. This work plans to fill this gap in knowledge by providing a simple method, based on equivalent stresses and strains, that identifies the failure modes when the Tsai-Wu failure criterion is near the on-set of damage. Using this novel method, it is possible to implement classical damage evolution laws based on the formulation of Matzenmiller. The proposed damage model is implemented in the commercial finite element software ABAQUS using user-subroutine UMAT, and the numerical results are compared with experimental data obtained earlier by other authors for different applications of glass fiber reinforced polymer (GFRP) structures. The numerical stabilization is achieved by using a new implicit to explicit material time step algorithm.

Automated summary

This paper presents a novel approach to develop an orthotropic damage model based on the original 3D Tsai-Wu failure criterion. The approach fills the gap in knowledge by identifying the location and failure modes of damage, and can be verified with existing data.