Study on Approximation of Thermal Deformation for Constraint on Stacking Sequence Optimization

Abstract

This paper discusses optimum design of a stiffened composite panel, which is used in aerospace structures. Anisotropic thermal expansion coefficients of the composite laminates causes complicated deformation of the panel after the curing. In previous researches, stacking sequence optimizations were performed without considering thermal deformation: a response surface was used to obtain an objective function, and lamination parameters were sued as variables for the response surface of the objective function such as buckling load. However, the thermal deformation must be considered as a constraint factor for actual composite structures. In the present study, therefore, thermal deformation is dealt with as a constraint for a stacking sequence optimization problem. Three surrogate models of the thermal deformation are discussed here: a conventional method using lamination parameters; a new method using thermal coefficients; a modified new method As a result, the modified new method is shown to be effective for the surrogate model.