Abstract: In view the breakage failure of generator bracket in a light truck, through the hammering modal test and vibration test, the cause of the failure is determined that the first order frequency is too low and resonance occurred. According to the test results, the generator bracket structure is optimized by strengthening its stiffness and reducing the height of generator. The optimized generator system is analyzed by finite element method, the modal and strength met the design requirement. Finally, the optimized generator system is tested. The first-order frequency is close to the calculated result, and the generator vibration amplitude is greatly reduced.

Key words: Light truck; Generator bracket; Bracket breakage; Resonance; Finite element

摘要： 针对市场某轻型卡车发电机支架发生断裂的现象，通过锤击法模态测试和振动测试， 确定故障原因为一阶频率过低，系统发生共振。根据测试结果优化发电机支架结构，加强其 刚度，降低发电机重心位置；有限元法分析优化后的发电机系统，模态和强度均满足设计要 求。最后对优化的发电机系统进行测试，一阶频率与计算结果接近，且发电机振动幅值大幅 度减小。

关键词: 轻卡；发电机支架；支架断裂；共振；故障分析