A nonlinear finite element analysis for composite materials

A plasticity model for unidirectional fiber-reinforced composite materials was implemented in a three-dimensional finite elements analysis. A second-order Runge-Kutta method with an adaptive step-size control scheme was used in the computation of elastic-plastic stress increment. In order to model the contact loading of a rigid cylinder on a specimen in the three-point short beam shear testing of composite materials, a simple contact modeling scheme was also developed. The stress increment updating scheme and the contact modeling algorithm were implemented into the analysis. Some numerical examples were presented and these numerical techniques were shown to be more efficient than commonly used conventional schemes while generating comparable results. The numerical results for the modeling of a short beam shear test method for unidirectional composite materials were also presented as an application oi the present three-dimensional nonlinear finite element analysis.