基于拉拽安全性能的汽车座椅优化设计

Design Optimization of Vehicle Seats for Pull Safety Performance

首先,基于国家标准GB14167—2013《汽车安全带固定点》中的座椅拉拽安全性能试验规程对汽车座椅单体进行建模仿真,并经试验验证模型的可靠性。然后,为改善座椅拉拽安全性能并实现轻量化,同时考虑NVH性能对座椅结构模态频率的要求,从概念设计阶段到详细设计阶段,对座椅骨架进行拓扑优化和尺寸优化。在概念设计阶段,通过多个静态载荷模拟座椅在动态载荷下的变形趋势,以静态载荷下的座椅骨架总柔度最小为目标,设计区域体积和1阶模态频率为约束,对座椅结构进行拓扑优化。在此基础上,通过相对灵敏度分析从19个部件中选出10个部件的板厚度作为设计变量,通过哈默斯雷和拉丁超立方采样的试验设计,构建了移动最小二乘法(MLSM)近似模型。以质量和滑轨最大变形量最小为目标,采用多目标遗传算法(MOGA)进行优化求解,获取Pareto最优解。结果表明:在座椅第1阶模态频率不低于19 Hz的前提下,优化后的座椅质量下降了5.7%,滑轨最大变形量减小了16.2%,在改善座椅拉拽安全性能的同时实现了轻量化。

Firstly,according to the test procedure for seat pull safety performance,provisioned in National Standard GB14167—2013“Safety⁃belt anchorages,ISOFIX anchorages systems and ISOFIX top tether anchorages for vehicles”,the modeling and simulation of a single vehicle seat are conducted with the reliability of the model ver⁃ified by test.Then for improving the seat pull safety performance and achieving lightweighting,with consideration of the requirements of NVH performance on the modal frequency of structure,the topology optimization and dimension optimization on seat frame are performed from concept design phase to detail design phase.In concept design phase,the seat deformation trend under dynamic loading is simulated by multi⁃static load,and a topology optimization is carried out on seat structure with minimizing the overall compliance of seat frame as objective,the volume of design zone and the first order modal frequency as constraints.On this basis and through the relative sensitivity analysis,the panel thickness of 10 components is selected from 19 components as design variables.By adopting the design of experiment with Hammersley and Latin hypercube samplings,approximate models are constructed with moving least squares method.With minimizing the mass and the maximum deformation of seat rail as objectives,a simulation pro⁃ceeds by using multi⁃objective genetic algorithm with the Pareto optimal solution obtained.The results indicate that after optimization,the seat mass and maximum deformation of seat rail reduce by 5.7%and 16.2%respectively while the first order modal frequency is not less than 19 Hz,achieving both the improvement in seat pull safety perfor⁃mance and lightweighting.