拓扑优化在单缸机缸体轻量化设计中的应用

Application of topology optimization to light-weight design of single cylinder engine

为将三维拓扑优化技术应用于发动机气缸体轻量化设计中,对采用变密度拓扑优化方法的拓扑优化技术进行了研究.以缸体上施加最大爆发压力工况为边界条件,以缸体总柔度最小化为优化目标,以缸体重量为约束条件,对缸体进行拓扑优化.拓扑优化后的结构考虑加工、装配等因素,进行合理的重新建模后,分析了最大爆发压力工况和最大侧向力工况的气缸体应力分布,两种工况下优化后的缸体最大应力比原气缸体降低,应力分布更加均匀.结构优化方法用于缸体的等强度轻量化设计中,很容易确定缸体的最佳形状,并能减少重复设计验证的次数.

In order to apply the 3D topology optimization to the light-weight design of engine block, the topology optimization based on the variable density was studied. When performing topology optimization,the boundary condition was taken when the engine was at the moment of gas explosion, the minimum compliances of the cylinder block were taken as the single objective, and the mass as the constraint. Considering the factors of machining and assembling, CAD model of the cylinder block was rebuilt. The stress distribution of the optimized cylinder block was analyzed at the load of gas explosion and maximum piston knocking. At both load cases the maximum stress of the optimized cylinder block was lower than the original one, and the stress distribution was more even. Therefore, the structure optimization used in the light-weight design can determine the shape of the cylinder block easily and decrease the repetitions of design and validation.