Effect of material and connector stiffness variability on load response of polymer composite structural systems

Polymeric composites are extensively used in aerospace and light weight civil engineering structures. The behavior of structural members and sub-assemblies made of these materials depend on the stiffness of the individual components and the connectors utilized for composite action.;Finite element method of analysis is utilized to investigate the effects of material and connector stiffness variability on load response of polymeric composite structural members and sub-assemblies. The shear connectors in the composite members and sub-assemblies are modeled by connector elements to simulate the slip behavior of the system. The study deals with polymeric composite T-beams and deck systems. In the development of the finite element model, the mechanical and physical properties of the components -- modulus of elasticity, coefficient of thermal expansion, Poisson's ratio -- were properly accounted for in order to simulate the behavior of the real system. The applicability of the finite element model for analyzing T-beams and deck systems is verified by comparing the predicted responses with well established analytical solutions.;The influence of discontinuities (gaps) in the decking layer of polymeric composite deck system is also investigated. These discontinuities (gaps) are accounted for in the finite element model by introducing elements of low stiffness at the location of the gaps. A method of estimating the response of polymeric composite members and sub assemblies at different service temperature was also developed.