By means of structural optimization,not only the weight of structures can be reduced,but also the strength,stiffness,vibration behavior,buckling stability,and other performances of structures can be improved efficiently.Structural optimization is an important research direction in the computational mechanics and modern design field.It is difficult to find global optimum result by using traditional optimization methods to solve large-scale and complicated nonlinear and discontinuous optimization problems in practices.The Particle Swarm Optimizer (PSO),a swarm intelligence algorithm,can undertake this responsibility.Global optimization and connotative parallel searching is one of its most important characteristics.In this thesis,the basic theory of particle swarm optimizer is first analyzed.And the program system of this algorithm is realized.Then an improved of PSO is proposed.This method is very useful to promote the efficiency of PSO and precision of results.Finally the correctness and feasibility of this method are verified by several numerical examples.In present,the optimum design of truss structure is a very meaningful and valueable topic in engineering fields.PSO is applied to sizing optimization,configuration optimization, topology optimization and layout optimization by employing the software JIFEX.It is belived that the work presented in this thesis should provide good theoretical background for the design of the truss structure. |