Research On Structural Topology Optimization Of Engine Piston

Piston is the key part of engine,its structure and performance will directly related to the life and working efficiency of the engine.Based on the unique advantage of topology optimization in structural quality optimization and efficient distribution of material,a topology optimization analysis is given to the original model of one engine piston considering the manufacture, assembly and stability of piston.The paper generally evaluates the optimization effect of the optimization model of the piston.First, based on the principle and expression method of topology optimization,the paper discusses the material interpolation theory of the density method of topology optimization.It also derivates the formulas of optimization algorithm and sunmaries the density interpolation method of solid isotropic material with penalization (SIMP). On the basis,the three-dimensional entity model of the piston is built. In the view of the static characteristic,strength analysis and stiffness analysis of the finite element model of the piston is calculated under the temperature field,stress field and thermal-machine coupling field. In the view of the dynamic characteristic,the paper completes the model analysis of the piston.Secondly,according to the process of topology optimization analysis,on the basis of thermal-machine coupling analysis,the paper completes the topological iterative calculation of the piston by defining piston optimization space and establishing the topological optimization model.The model is that cell density as the design variables,displacement response and stress response as constraint function,the minimum volume fraction as the objective function.Combined with assembly relation and process characteristics of the piston,the optimization result is given a moderate modification and round smooth processing.At last,the new model of the piston is obtained by topology optimization. Finally,the paper analyses and evaluates the optimization effect of the model of piston,through contrast the stress,deformation, volume (quality) and modal characte-ristics before and after the topological optimization, not only does reach the purpose of the piston structure optimization,but also realization the lightweight design of the piston in a certain extent, and it also indirectly proves the effective and correct of the density interpolation method.