Stress-strain analysis of specimens subjected to tensile loading during moisture uptake

Abstract

Abstract: A robust and efficient numerical method for the calculation of the internal stress state that develops within structures subjected to mechanical and steady state or transient hygroscopic loading conditions, has been developed. The method encompasses a layer by layer approach whereby the structure is discretised into plies with different material properties corresponding to the different ply moisture content. The proposed method has been validated against finite element solutions, and results from its application on a fully characterised EDT (technical name) polymer binder are presented. The impact of the moisture induced viscoelastic behaviour on the structural response of the case studied is highlighted and discussed. The approach could be used for different structures operated both open-air and indoor in automotive, marine, airspace, and other applications, e.g., for interior parts in the automobile industry. Keywords: moisture sorption; transient hygroscopic conditions; viscoelasticity; epoxy matrix; stress-strain analysis; tensile loading; automotive composites.