Modeling of progressive debonding of interphase- matrix interface cracks in particle reinforced composites using VCFEM

Abstract

The Voronoi cell finite element model (VCFEM) containing three phases of inclusion, interphase and matrix in an element has been proven to be very accurate and efficient in the analysis of inclusion reinforced composites. In this paper, we extended our previous study to include the matrix-interphase interface debonding problems. The traction-free at the debonded matrix-interphase interface and the traction reciprocity at the bonded matrix-interphase interface were introduced into the functional by displacement as Lagrange multiplier. A modified complementary energy functional was constructed. When the matrix-interphase interface was debonded according to critical normal stress law, additional nodes are added as node pairs with existing nodes whose stress exceeds the critical value. This process was interated until the stress of all nodes did not exceed the critical value. Thus, the mesh re-division technology was realized for the interface debonding progressively. The proposed VCFEM is validated by results from MARC. The results show that the proposed VCFEM was more efficient. Based on the developed model, the influence of interphase properties on stress-strain cure was studied during the debonding process. This showed that the interphase modulus and thickness had great influence on the overall mechanical behavior of composites.