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.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.