从自由试验提取具有弹性支承的阻尼约束结构的主模态

作者已对边界固持(即刚性支承)的无阻尼和有阻尼的约束结构，从自由试验提取其实模态和主模态的方法进行过系统的研究，同时，对于具有弹性支承的无阻尼约束结构模态的提取，也建立了一种可行的方法。这些方法和技术途径都取得了良好的结果，仅剩下具有弹性支承的阻尼约束结构主模态的提取方法尚无。对此，本文企图建立一种工程中可行而实用的方法。在该方法中，阻尼分为瑞利阻尼和粘性阻尼两种模型，这样，可以根据不同结构选用不同阻尼模型下的提取方法。数值模拟结果表明，本文建立的方法虽然不像以前无阻尼下的类似方法那样，具有普遍性，即取任何支承刚度(可以很大或很小)都可获得满意结果。不过，对于工程中常见的支承刚度比结构刚度大或等量级的实际情况，本文方法是能取得满意结果的。这表明，本文方法已基本满足工程要求了。

Extraction of Normal Modes of Constrained Damping Structure with Elastic Supporting from Free Test

For undamping and damping constrained structures with rigid supporting(i.e. fixed boundary),the methods of extracting their real and normal modes from free test data have been addressed systematically.In addition,for constrained undamping structure with elastic supporting a feasible method for extracting the constrained modes from free test was also established.Correspondingly,a method for extracting normal modes of constrained damping structure with elastic supporting will be proposed in this paper.Damping model is taken as two kinds:Rayleigh(proportion)damping and viscous damping.The numerical simulation results show that for practical case of supporting stiffness that is larger than and/or equal to structural stiffness,the present method can obtain satisfactory results.This means that the method described in this paper satisfies basically engineering requirement.