基于振动传递函数的排气系统悬挂点位置优化

Optimization of Exhaust Hangers Location Layout by Vibration Transfer Function

提出一种基于振动传递函数法的排气系统悬挂点位置优化方法.以某混合动力轿车悬挂点位置布置为例,通过有限元法建立从发动机激励到排气系统的振动传递函数数值模型,得到排气系统各点在振动频带内的总相对位移响应,由总相对位移响应最小确定悬挂点位置的优化方案.研究表明,此方法中发动机激励、动力总成与排气系统的模态参与因子和模态振型共同确定悬挂点位置.比较优化方案与初始方案的实车验证数据可得,优化方案中排气系统和座椅导轨的振动加速度降幅超过17%,证明基于振动传递函数的排气悬挂点位置布置方法能用于悬挂点位置设计中.

An optimization method about layout of exhaust hangers location was presented by vibration transfer function （VTF）. Mathematical model of the VTF from engine excitation to exhaust was established with finite element method by taking the layout of hangers location in a hybrid electric vehicle （HEV） as an example. Then summation of relative displacement response of points on the exhaust was calculated in range of vibration frequencies. Finally, an optimized layout was obtained on the basis of the minimum of the summation of relative displacement response. The results indicate that the hanger location is decided by engine excitation, modal participation factors and modal vectors of powertrain and exhaust together in the VTF method. It was proved that vibration accelerations of the exhaust and rail of seat in the optimization layout reduced by more than 17 % in comparison with the initial one based on the test data of t he HEV. So the optimization method about layout of hangers location by the VTF can be resorted to hanger location design.