中巴车铝合金立柱截面多目标优化

立柱是轻量化中巴车身的核心构件,其综合力学性能取决于型材截面形态。提出一种基于响应面的截面特征参数多目标优化方法,首先进行6063铝合金材性试验及立柱构件的拉伸和弯曲试验,测得材料的力学性能参数、立柱轴向和侧向的极限承载力。试验结果表明立柱构件的侧向受力能力远小于轴向受力能力。为提高立柱综合性能,采用最优拉丁超立方试验设计分析,选取敏感度大的截面特征参数作为设计变量,以质量、最大变形位移、最大应力的最小化为综合设计目标,建立多目标优化的数学模型。基于Kriging算法构建最大变形位移和最大应力的响应面仿真模型,应用多目标遗传优化算法(MOGA)全局寻优得到最优解。优化方案最大变形减小0.62%、最大应力减小11.06%、质量减小12.48%。

Section Multi-Objective-Optimization of Midibus Aluminum Alloy Pillar

Pillar is the core structure of lightweight midibus,and its mechanical properties decide on cross-section form. A muti-objective optimization method of cross-section’s characteristic parameter based on response surface method(RSM)was presented in this paper. Did the experiment of uniaxial tensile test and bending test of aluminum alloy pillar,and got material parameters,axial ultimate capacity and lateral ultimate capacity. To improve pillar’s mechanical properties,did the Design of Experiment with Optimal Latin Hypercube method and selected cross-section’s characteristic parameters which sensitivity is noteworthy,and took it to design variable. With mass,maximal deformation and maximal stress as design objectives,and the muti-objective optimization model was proposed. Response surface models of maximal deformation and maximal stress was built based on Kriging algorithm. Multi-Objective Genetic Algorithm(MOGA)was carried out to find optimal solution. The mechanical property of new structure have been improved,shows that reduce 0.62% of maximum deformation,11.06% of the maximum equivalent stress,and 12.48% of the mass under the bending and torsion load.