Elastic-degrading analysis of pultruded composite structures

This study presents a combined micromechanical and structural modeling approach for the elastic-degrading (ED) analysis of pultruded composite materials and structures. Pultruded composites with continuous filament mats and roving layers are considered in this study. The overall effective response of the pultruded composite material is predicted using 3D micromechanical models for the layers that span the thickness. These micromodels account for the nonlinear response in their matrix while the fiber constituent is assumed to be linear elastic and transversely isotropic. The nonlinear material response of the matrix is achieved using an isotropic ED model that better captures the effective nonlinear behavior of the pultruded material when compared with using a J2-plasticity type model. A structural framework analysis is generated by integrating the micromechanical models within 3D or layered-shell finite element (FE) models. The result is a general global-local modeling approach for the nonlinear ED analysis of pultruded structures. Off-axis pultruded coupons were tested to examine the prediction capability of the micromodels for the nonlinear effective material behavior. A structural verification is also carried out by using detailed FE models of off-axis pultruded plates with a central hole, and four-point bending tests of pultruded coupons. The proposed micromodels combined with FE are able to effectively predict the nonlinear material and structural responses. (C) 2003 Elsevier Science Ltd. All rights reserved.