Micromechanical Constitutive Model of Progressive Crushing in Random Carbon Fiber211 Polymer Matrix Composites

摘要

A micromechanical damage constitutive model is presented to predict the overall211u001eelastoplastic behavior and damage evolution in random carbon fiber polymer matrix 211u001ecomposites (RFPCs). To estimate the overall elastoplastic damage responses, an 211u001eeffective yield criterion is derived based on the ensemble-volume averaging 211u001eprocess and first-order effects of eigenstrains due to the existence of 211u001espheroidal (prolate) fibers.The proposed effective yield criterion, to ether with 211u001ethe assumed overall associative plastic flow rule and hardening law, constitutes 211u001ethe analytical foundation for the estimation of effective elastoplastic behavior 211u001eof ductile matrix composites. First, an effective elastoplastic constitutive dama 211u001ee model for aligned fiber-reinforced composites is proposed.A micromechanical 211u001edamage constitutive model for RFPCs is then developed. The average process over 211u001eall orientations upon overning constitutive field equations and overall yield 211u001efunction for aligned fiber-reinforced composites i s performed to obtain the 211u001econstitutive relations and effective yield function of RFPCs.The discrete 211u001enumerical integration algorithms and the continuum tan ent operator are also 211u001epresented to implement the proposed dama e constitutive model.The dama e 211u001econstitutive model forms the basis for the progressive crushing in composite 211u001estructures under impact loading.