客车车架裂纹生成原因分析

汽车在行车过程中，车架纵梁出现严重开裂现象是汽车的致命故障。通过静力和动力试验分析车架开裂局部裂纹形成的原因，结果表明该车型车架开裂附近静应力的水平不高及动应力过大是造成车架开裂的主要原因。实测中动应力随车速变化，当车速为90km／h时，动应力达到最大值，裂纹附近总应力超过200MPa。该结果与实际车架开裂发生在高速情况相一致。

Serious crack crevice occurrence on motor vehicle frame during driving is a fatal trouble. Cause of framelocal crack crevice occurrence is analyzed for a bus through static and dynamic test, of which the main cause shows thatstatic sires near the crack crevice is not so high but is dynamically over stressed. Practical dynamic stress measurement indicates that it is changed in accordance with bus speed, which reaches to its maximum at 90 km/h, the value of total stress