Hygrothermal Expansion Coefficients of Composite Materials Studied by a Simple Statistical Approach

Abstract

In this article, an investigation of the coefficients of hygrothermal expansion for a general class of randomly-oriented composite laminate is presented. A simple random statistical analysis has been used to demonstrate that under certain conditions, for instance, a laminate with 40 plies or more, the mean values of the coefficients of hygrothermal expansion in the randomly-oriented laminate are close to those values evaluated from the classical hygrothermal-elastic lamination theory. Also, the influence of the various lamina material properties E2JEI, G₁₂/E₁ and v₁₂ as well as the lamina hygrothermal expansion coefficients axl/(i₂ and 41/2 to the coefficients of hygrothermal expansion of the laminate are investigated. The results from this statistical analysis provide a set of general guidelines for designing the coefficients of hygrothermal expansion of the composite laminates to meet different environmental conditions in engineering application.