冲击荷载进行桥梁模态试验的研究

桥梁模态中多通过天然脉动作为激励力,但是很多情况下由于脉动信号的不可控制性而导致试验结果较差,而将力锤的脉冲激励应用到实际桥梁测试中可得到理想的试验结果。分析了不同试验方法在桥梁中使用的特点,对不同激励方法得到的试验效果进行比较,指出在不同情况下使用不同试验方法的效果和限制。介绍了力锤具有能量集中的优点,且其频率范围符合桥梁的特性。最后通过实例介绍力锤激励的方法,并通过试验得到较好的桥梁竖向动力特性。

Research on Bridge Modal Identification by Impulse Load

The paper compared different methods for bridge test and indicated the effects and limitations of different test methods under different conditions. It is concluded that it is hard to control the impulse signal by use of natural dynamic test and that the impulsive excitation by hammer can be controlled with good results, owing to its characteristics of concentrated impulsive excitation with frequency range close to bridge's eigenfrequency. A practical example was given by use of hammer to stimulate a highway bridge with good vertical dynamic parameter results.