Application of Reduced Stiffness of Complex Laminate in Finite Elements for Chair Analysis

This paper presents a numerical procedure for the analysis of complex laminate structures. The procedure is based on the application of reduced stiffness of complex laminate. Introduction of reduced stiffness of composite facilitates both linear and nonlinear numerical integration, i.e. the tangential stiffness matrix is translated in the classical plate theory problem. The formulated numerical procedure was implemented in the program system KOMIPS. Special subroutine REDKRUT that calculates reduced stiffness of the laminate was written, and its application in numerical verification of experiments conducted on chairs was presented in (Nestorovic, 2010). At the end of this work, for 3D stress and strain analysis of veneer composites, recommendations were given for experimental determination of all nine independent material constants Ex, Ey, Ez, vxy, vxz, Gxy, Gxz, Gyz, fi ve of which were determined in the previous paper of the author (Nestorović, 2010).