2.模态试验中该用多少个激振器?

模态激励的普遍问题

The number of shakers is often a difficult question to answer. Frequently we are limited by the total number of output sources in the data acquisition system or shakers available in the test lab for modal testing. Usually two to four shakers are sufficient for most tests, particularly when testing larger structures like automobiles or aircraft; tests with more than five shakers are rare. Ultimately, there need to be enough shakers acting as reference locations positioned so that all of the modes of the structure are adequately excited and observed and good frequency response measurements are obtained. This includes having multiple shaker/reference locations to resolve repeated roots and/or closely spaced modes.

激振器的数量通常是一个难以回答的问题。对模态试验,我们经常受数据采集系统中的输出源或者试验室内已有的激振器总数的限制。对大多数试验,通常2到4个激振器就足够了,特别是当测试大型结构时,如汽车或飞机;用超过5个激振器的试验非常少见。最终,需要有足够的、作为参考点的激振器固定在那里,这样就可以充分激起和观察到结构的全部模态,得到良好的频响测量结果。这包括有多个激振器/参考点位置来解决重根和/或密集模态问题。