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A Computational Program for Multiple Scale Analysis of Failure in Non-Uniform Composite Materials
Final rept. 1 Jul 2001-31 Mar 2006
OHIO STATE UNIV RESEARCH FOUNDATION COLUMBUS
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This work has developed an adaptive concurrent multi-level computational model for multi-scale analysis of composite structures undergoing damage initiation and growth due to microstructural damage induced by debonding at the fiber-matrix interface. The model combines macroscopic computations using a continuum damage model with explicit micromechanical computations of stresses and strain, including explicit debonding at the fiber-matrix interface. Three hierarchical levels of different resolution adaptively evolve in this to improve the accuracy of solutions by reducing modeling and discretization errors. The levels include 1 level-0 of pure macroscopic analysis using a continuum damage mechanics CDM model 2 level-1 of asymptotic homogenization based macroscopic-microscopic RVE modeling to monitor the breakdown of continuum laws and signal the need for microscopic analyses and 3 level-2 regions of pure micromechanical modeling with explicit depiction of the local microstructure. The macroscopic computations are done by conventional FEM models. For micromechanical analysis, the Voronoi cell finite element modelVCFEM has been improved for studying the interfacial debonding. A new eXtended Voronoi cell finite element model X-VCFEM has been developed for modeling interfacial debonding with arbitrary matrix cohesive cracking in fiber-reinforced composites. The cracks are modeled by a cohesive zone model and their incremental directions and growth lengths are determined in terms of the cohesive energy near the crack tip. The power of this method is established through numerical examples.
APPROVED FOR PUBLIC RELEASE