基于仿真和试验的排气系统螺栓断裂问题研究

Analysis of exhaust system's broken bolt based on simulation and test

针对某牵引车排气系统螺栓断裂故障问题,结合试验与CAE仿真提出了解决方案。通过模态和振动试验,确定螺栓断裂故障是由于排气系统固有频率与发动机常用转速的激励频率相吻合导致,提出从排气系统质量分布、波纹管位置以及支架结构等方面进行改进的方案。CAE仿真分析结果表明,优化后系统固有频率明显提高且避开了发动机常用转速的激励频率。试验验证表明,该方案提高了排气系统的可靠性,具有可行性。

Aiming at the problem of bolt breakage in exhaust system of a tractor,a solution was proposed by combining test and CAE simulation.Through modal and vibration tests,it was confirmed that the bolt breakage fault was caused by the natural frequency of the exhaust system and the excitation frequency of the common engine speed.The results of CAE simulation show that the natural frequency of the exhaust system could be significantly improved by improving the mass distribution of the exhaust system,the position of the bellows and the support structure,and the excitation frequency of the common engine speed could be avoid.The test showed that the scheme improved the reliability of the exhaust system and was feasible.