Dimensionally stable laminates under thermal loading and their applications

Abstract

There exist many types of structures, which are required to have stable dimensions within a wide range of temperatures. The specific nature of composites allows finding special conditions when a laminate stacking sequence can provide zero thermal expansion coefficients in one or more directions. This allows the structure being designed to have the same dimensions in a wide range of temperatures. This work is aimed to find mathematical conditions, which guarantee in-plane zero CTE at least in one direction. As an application of thermally stable laminates a rotating disk is chosen. The mathematical model for such a disk is presented. Among investigated materials there was not found any of them, which can be used to layup a laminate with zero CTEs in two directions. However, all investigated materials can be used to layup many laminates with zero CTE in one or another direction. Moreover, it was discovered a laminate might have a zero CTE, if the lamina has zero or negative CTE at least in one direction. It was found the stresses, which appear in a laminated disk caused by centripetal forces, are insignificantly low in comparison to the thermal ones within the investigated ranges of angular velocity and temperature.