Buckling Optimization Of Composite Laminated Plates Based On The Simulated Annealing Algorithm

Composite materials have been widely used in fields of aeronautics and astronautics because of its distinct advantage of high strength ratio, high stiffness ratio, high modulus rate and tailorability. As one of the essential components of aircraft structures, composite laminated plates is payed attention by more and more researchers.With the development of the modern aerospace technology, the demand of impetus and load-bearing capacity of aircrafts become higher and higher. The structure optimization design of composite laminated plate which is the main load-bearing component of aircraft is an essential research direction. The change of fiber orientation angles and stacking sequences has a remarkable impact on structural performance, thus it is of important practical significance to analyze and optimize the structural stability of composite laminated plates.Due to the different orientations of composite laminated plates are discrete variables, that is, use the traditional mathematical programming method to optimize this solution is difficult. However, an algorithm called simulated annealing(SA) which has been widely applied in recent years can be very good to solve discrete variable optimization problems. Meanwhile, the simulated annealing algorithm have obvious advantages on optimizing the stacking sequences of composite laminated plates. Researches on the stability analysis and structure optimization are presented in this paper.Firstly, the stability of composite laminates plate is analyzed. Classical laminated plate theory and stability theory are combined to deduce the calculation method of the critical buckling load of composite laminates under compression and shear loading. After that numerical analyses are used to verify the accuracy of calculation theory.Secondly, to analyze and improve the traditional simulated annealing algorithm used in this article. Introduce the memory function in the algorithm in order to avoid missing the optimal solution when accept the probability. According to the research contents in this paper, using parallel computing and set up double threshold could avoid the local optimal solution appeared in the process of optimization and accelerate the rate of convergence at the same time.Finally, an optimization model to optimize the stability of composite laminates is created. The critical compressive load is chosen as objective function, select fiber orientation angle and stacking sequence of composite laminates plate as design variables. Adopting modified simulated annealing algorithm to gain optimal lay angle and stacking sequence of composite laminates plates, and it can provide basis for practical application.