基于微粒子群优化算法的差速器壳体轻量化设计

针对汽车差速器的轻量化,提出了基于微粒子群优化算法和参数化模型相结合进行优化的设计方法.通过计算模态和试验模态相结合,验证了差速器壳体有限元模型的准确性;基于微粒子群算法,建立了以质量最小和安全系数均方根值最大为目标的优化模型,进行了轻量化设计.优化结果显示:壳体质量由优化前的6.26 kg下降到5.67 kg,减轻了10.4%;优化后壳体的最大应力、最大应变和最小安全系数等性能指标均有不同程度的提高,验证了轻量化是成功的.

Lightweight design of differential case based on particle swarm optimization algorithm

The lightweight design for automotive parts and components is a complex, multi-constrained problem concerning system optimization and satisfies various structural performance requirements. Existing studies on the lightweight design for automotive parts and components primarily focus on the automobile body design. Most of them focus on plastic material rather than the castings widely used in automobiles. This paper proposes a lightweight design for the casting of the differential mechanism shell in the assembly of the automotive drive axle. The paper focuses on the shell of the automotive differential mechanism and proposes a design method for optimization based on the combination of Particle swarm optimization algorithm and parameterized model. The main contents include: to first establish a parameterized, three-dimensional model for the differential mechanism shell, calculate the modal numerical values of the first 6 orders of the differential mechanism shell, derive the maximum modal numerical value among the first 6 orders, i.e. 6.22% only through modal test contrast, thus verify the correctness of the model. Second, it establishes three limiting conditions of the differential mechanism, including: the automotive advancing condition during transmission with highest torque of the engine and fist gear of the gear box, and automotive reversing condition and twisting fatigue condition with the highest torque of the engine and reverse gear of the gear box. Based on the PSO algorithm, the paper establishes an optimization design with the goal of minimum mass and maximum root-mean-square value of the safety coefficients and a lightweight design in combination with the parameterized model of the differential mechanism shell. It can be inferred by comparing the relevant performance parameters of the differential mechanism shell before and after the lightweight design that: the maximum stress of optimized model decreases by 12.55% under the advancing condition; the maximum stress of optimized model is 5.74% under the reversing condition; under the condition of torsion fatigue, the minimum safety coefficient has risen to 1.35 from 1.12 after optimization; the shell weight has fallen to 5.67 kg from 6.26 kg after optimization with reduction of 10.4%; and the above analyses demonstrate that the lightweight design is successful.