锤击法在细长体两点激振试验中的研究及应用

Study and Application of Hammer Method in the Slender Dual-exciter Vibration Test

细长体进行振动试验时前后输入的试验条件差异较大,进行两点激振试验前激励点和控制点选取需要参考试验件前三阶的模态信息。对结构进行激励,测量响应的传递函数,通过计算机解算可以得出结构的基本模态信息。对试验件进行锤击是一种瞬态、宽频激励。用移动锤击法对自由状态下的细长体进行模态测试,获取了前三阶的模态信息,并根据振型的波峰和节线位置选取两点激振试验的夹具夹持位置和控制点,满足了试验控制要求。

The test conditions of the head and tail of a slender varies widely in vibration test. The first three order modal results can be referenced when selecting the excitation and control location before the dual-exciter vibration test. Exciting specific location of test pieces, and measuring the transfer function of the response from exciting, the basic modal information of the structure can be calculated by computer. Hammering on the structure is a instantaneous wideband excitation. The fixture and control position is confirmed by referencing the position of modal shape peak and node lines from modal results, and meet the requirements of the control in dual-exciter vibration test.