The Particle Swarm Optimizer And Its Application To The Plate Structural Optimal Design

In this present years. Great more attention has been paid to the optimal design, due to the fact that it can reduce the cost. Most of the traditional algorithms, which are based on the numerical linear and nonlinear programming methods require substantial gradient information and usually seek to improve the solution in the neighborhood of a starting point. The traditional optimal algorithms provide a useful strategy to obtain the global optimal solution in a simple model. However, many practical engineering problems are very complex and hard to solve by the traditional optimal algorithms. The Particle Swarm Optimizer, which is a swarm intelligence algorithm, has been proposed. It is a population-based optimization algorithm and requires few parameters to be implemented.Firstly, this thesis presents that the three optimal algorithms including the particle swarm optimizer (PSO), the particle swarm optimizer with passive congregation (PSOPC) and the heuristic particle swarm optimizer (HPSO), are combined with finite element method to optimize plate structures in this paper. The calculation module for plate optimal problem is developed with APDL language based on ANSYS software, which call the macro file to calculate, such as model macro file, solve macro file, boundary macro file, result macro file and so on.On the premise of a given set of material parameter, structural boundary shape and condition, Design variables thickness of plate which is designed in two type variables of sequential and discrete, is designed to minimize the structural weight subjected to the constraint condition.The thickness of plate is designed to be independent variable of the particle swarm, and stress and displacement constraints are designed to be constraints variables, the particle swarm search in space to get the design result which satisfies the size, stress and displacement constraints.Based on ANSYS software, by using of APDL language (Ansys Parametric Design Language),the calculation module for plate optimal problem is developed with APDL language based on ANSYS software. Three optimal design examples are calculated with three different optimizers, which show the method proposed in this paper is feasible and the heuristic particle swarm optimizer(HPSO) is the most efficient method.Finally, the HPSO is applied to the punching plate optimal design. The feasibility is tested for practical application of the algorithm proposed in this thesis.