Finite element modelling and optimization for controlling the residual thermal stresses of laminated composite tubes

Abstract

The present paper describes the use of the laminated plate theory (LPT) to optimize the architecture of laminated ceramic matrix composite tubes possessing high thermal cracking resistance. The method estimates the induced thermal residual stresses of laminated composite tubes with various stacking sequences and laminae thicknesses during cooling from a processing temperature of 1700 °C to room temperature using a general purpose finite element program ANSYS. The optimum structure of the ceramic matrix composite (CMC) tubes was achieved through continuous iterative calls between the finite element output and an optimization program. The design variables considered in this study are the laminae thicknesses and the stacking sequences of various volume fractions ranging from 0 to 40% of SiC whisker-reinforced mullite. An optimum design of the laminated composite tube consisting of four laminae of [30/40/20/10] stacking sequence with the 40% layer on the inside surface and the 10% layer on the outside surface is achieved. This composite architecture is found to have high thermal cracking resistance as compared to other design cases.