Numerical modeling of fracture propagation in orthotropic composite materials using an adaptive phase-field method

We present an adaptive phase-field method for modeling crack propagation in orthotropic composites. The numerical approach extends an adaptive phase-field formulation, originally developed for isotropic linear elastic materials, to general orthotropic materials. The method to evaluate the constitutive tensor for a general orthotropic material is first discussed. The modification of the phase-field equation to incorporate the effect of orthotropy on damage evolution is then described. Simple numerical patch tests are formulated and used to validate the developed orthotropic material model. The coupled numerical framework is then utilized to study the influence of fiber orientation, and mechanical properties of fibers and matrix on the failure processes in orthotropic composites. The numerical studies indicate that the macro-scale failure behavior of laminates is primarily influenced by the mechanical properties of the matrix. Furthermore, the macro-scale fracture toughness of laminates increases when the individual lamina's transverse normal critical energy release rate is large in comparison with the critical energy release rate of the adhesive. In this configuration, partial delamination of the lamina interface is favored, and therefore, a progressive ductile failure of laminates is observed. This observation can be used to engineer laminates from a damage tolerance-based design perspective.

Automated summary

We introduce an adaptive phase-field method to simulate crack propagation in orthotropic composites. This method extends a formulation originally developed for isotropic linear elastic materials to general orthotropic materials. The constitutive tensor for orthotropic materials is evaluated and the phase-field equation is modified to incorporate the effect of orthotropy on damage evolution. Simple numerical patch tests are used to validate the developed orthotropic material model. The influence of fiber orientation and mechanical properties of fibers and matrix on failure processes in orthotropic composites is studied using the coupled numerical framework.