Study On Topological Optimization Method And Its Application Of Continuum Structure Based On Design Space Adjustments

Structural topology optimization of continuum has been treated as one of the most challenging tasks in structural optimization design, and is used as an innovative approach in the past three decades.This thesis proposes a improved method,based on the analyses of the advantages and disadvantages of present structural topological optimization methods.For the topological optimization design problems of autombile frame and some other three-dimensional continiuum structures, some simulations and resules are gives.To deal with large-scale problems that often occur in engineering applications and make the optimum topology obtained being of good 0-1 distribution material property, the thesis proposes a new structural topological optimization method,which is based on the idea of ICM method and SIMP method. Firstly, the rational approximation for material properties (RAMP) is adopted to design the topology structural stiffness matrix filter function, and the design space can be adjusted in terms of design space expansion and reduction. This capability is automatic when the design domain needs expansion or reduction, and it will not affect the property of mathematical programming method convergences. Secondly, an incomplete series expansion for structural displacements is given. To get a clearer topological configuration at each iteration step, by introducing the discrete condition of topological variables, integrating with the original objective and introducing varying displacement constraint limit measurements, optimal series models with multi-objectives is formulated to make the topological variables approach 0 or 1 as near as possible. Thirdly, incorporating the dual theory, a new continuum structural topological optimization method is proposed.From the above mentioned discussion,procedures of the proposed methods are implemented, and a lot of typical structural design examples are given.And the results of simulation examples show that the topologies obtained by the proposed method are of good 0-1 distribution property, there is stronger ability to obtain the optimum topology than the evolutionary structural optimization, and verify that this algorithm is robust and practicable. Thus it indicates the proposed method has good engineering application value.