Reliability-based Optimization Of Composite Laminate Structures

Composites, especially composite laminate structures, have been applied more and more widely in aerospace industry. In order to increase the ratio of thrust to weight and improve the comprehensive performance of aircraft, optimization design must be carried out. Due to the scattered properties of composite materials, the random variation of loads, the reliability of composite laminate structures must be considered in design process. Genetic algorithm (GA) is employed, which combines finite element method (FEM) and response surface method, to establish the reliability-based optimization design method of composite laminate structures in this thesis and the corresponding software code is written. The main research work includes the following: (1) Based on genetic algorithms and parametric FEM technique to find a reliability-based method for composite laminate structures, and the complicated optimization model of composite laminate is established. (2) Based on the characteristic of composite laminate structures, the encoding mode of GA is studied. Accordingly, a set of GA program is developed which is used for reliability-based optimization design of composite laminate structures. (3) Parametric FEM technique is used to analyze the mechanical performance and structural reliability of composite laminate structures. The parametric FEM code based on ANSYS is given. (4) Some optimization design examples are evaluated to demonstrate the reliability-based optimization method for composite laminate structures.