小型柴油机曲轴模态试验研究

Crankshaft Modal Experiment for Small Diesel

以4100QB柴油机曲轴为研究对象,首先在其自由和约束状态(发动机非运转)下进行模态测试,然后对运转状态下曲轴的振动进行测试分析,得出曲轴在不同状态下的模态参数。通过对比得出加飞轮和活塞连杆的曲轴在非运转约束状态下的模态特性与柴油机运转状态下的曲轴比较接近,可以基本反映运转状态下曲轴的模态特性;在自由状态下的模态特性与运转状态下有一定的偏差,但易激起各种模态,对曲轴模态的全面分析仍有一定的参考价值。

For the crankshaft of 4100QB diesel engine, the model testing was carried out in the free state and bound state, then the crankshaft vibration in operating state was measured and analyzed and finally the crankshaft modal parameters of different states were acquired. Through the comparison, the modal characteristics of crankshaft with flywheel and piston-connecting rod in the non-operating bound state were similar to its characteristics in operating state and could basically reflect the crankshaft modal characteristics in operating state. The modal characteristic deviation between non-operating free state and operating state existed, but the non-operating free state was easy to intrigue other modals, which was still helpful for thorough analysis of crankshaft modal.