考虑DPF的柴油机排气系统动力学分析及悬挂位置优化

Dynamics Analysis and Hanger Location Optimization of Diesel Exhaust System Considering DPF

微粒捕集器是柴油机排放后处理系统的核心装置。在考虑DPF的情况下,对柴油机排气系统的悬挂位置进行优化布置能很好地控制系统与车身间的振动能量传递。对考虑DPF的柴油排气系统进行有限元建模和模态分析,基于平均驱动自由度位移法,结合系统的实际情况优化选取悬挂位置。对柴油机排气系统进行静力学、约束模态、随机振动分析和随机疲劳计算,结果表明,所优化选取的悬挂位置合理,反作用力分布均匀,能避免共振,同时整个系统的疲劳总体损伤小于1,具有良好的抗疲劳性能。

The diesel particulate filter（DPF）is the core device of diesel exhaust after-treatment system.In consideration of the DPF,the transfer of vibration energy between the exhaust system and the vehicle body can be well controlled by optimizing the hanger location of the diesel exhaust system.The finite element modeling and modal analysis of the diesel exhaust system with DPF were carried out.Based on the average driving DOF displacement（ADDOFD）method,the hanger location of the whole system was optimized by combining with the actual situation.Through the static analysis,constraint modal analysis,random vibration analysis and random-fatigue calculation of the whole system,it is shown that the optimal selection of hanger location is reasonable,the reaction force of the hanger location is evenly distributed and the whole system can avoid resonance.The overall fatigue damage of the whole system is less than 1,which shows that the whole system has a good fatigue resistance performance.