Analysis of Particulate Composite Behavior Based on Nonlinear Elasticity and an Improved Mori-Tanaka Theory.

摘要

A micromechanical model for the analysis of particulate mechanical behavior is presented. Nonlinear effects are introduced in the model by a nonlinear elastic description of the matrix and through a modulus degradation routine. The first part of the study uses the experimental data from a range of glass bead/HTPB composites to back calculate the model parameters. The results showed that the model gave a good representation of the processes believed to control mechanical behavior. These processes Include partial particle deboning and progressive debonding from the largest to smallest particles throughout the strain history. The second part of the study examines the sensitivity of the model results to small changes In the adjustable input parameters. The residual bond in a debonded particle was found to have a dominating effect on the calculated results. Based on the sensitivity results, "best guess? Interaction and debonding parameters were selected to examine the predictive capability of the model. For glass bead!HTPB composites, the predicted composite stresses were within 1 0% of the experimental data. Dilatation was usually over-predicted. For glass bead/polyethylene and glass bead/polyurethane data found in the literature, predicted composite stresses were within 15% to 24%, respectively. The results showed that the model was capable of predicting the mechanical behavior of composites comprised of glass beads in HTPB, PU or HOPE matrices as long as characteristic adhesive parameters were available for each system.