Nonlinear Behavior of Fiber Composite Materials and Its Effect on the Postbuckling Response of Laminated Plates.

摘要

The nonlinear stress-strain behavior of unidirectional fiber composite material was examined. Two approaches were adopted. The first approach considers the stress-strain as nonlinear elastic relations, which are derived at through the use of a complementary energy density function, and takes into account the material symmetry. The second approach adopts the Ramberg-Osgood representation of one-dimensional stress-strain curves. By utilizing the deformation theory to express the nonlinear parts of the strain, a non-linear stress-strain behavior was obtained. An incremental formulation of these theories was implemented in a finite element analysis. These approaches were examined in the context of postbuckling analysis of thick-section laminated plates.