变频激励响应分析及模态阻尼反演理论研究  

Variable frequency excitation response analysis and inverse theory research of modal damping

作　　者：唐宇航 王雪仁 李欣 TANG Yu-hang;WANG Xue-ren;LI Xin(Unit 92578 of the PLA,Beijing 100161,China;Army Academy of Armored Forces,Beijing 100072,China)

机构地区：[1]中国人民解放军92578部队,北京100161 [2]陆军装甲兵学院,北京10072

出　　处：《船舶力学》2019年第11期1339-1350,共12页Journal of Ship Mechanics

摘　　要：实际工程结构中阻尼参数的获取往往依据规范经验或传统试验测试方法,然而经验取值普适性弱,传统测试方法中模态混叠难以有效分离、测点布置复杂以及某些情况下激励时序信号不易测量等问题,均给阻尼参数识别带来了困难。文章从多自由度模态叠加法动响应分析入手,提出了运用共振频率及其邻近频率激励响应反演系统模态阻尼的方法,推导了响应与阻尼比的理论关系,给出了“复合比例因子”的概念,并指出忽视系统共振响应与最大响应间的差异,往往会造成某些计算结果的大幅偏差。以某船船体梁数值计算为例,结合规范验证了阻尼反演理论及其公式的可靠性,并进一步对其进行了二维推广,完成了3块不同型式复合材料局部船体板单元结构模型的阻尼比测试,就其阻尼性能与钢材进行对比,发现复合材料在减振降噪方面有诱人的应用前景。该理论为潜艇总振动阻尼估算方法以及分布式阻尼研究提供了技术支撑。Damping parameters of practical engineering structures are often acquired by standardization and experience or traditional test methods.However,the applicability of experience value is poor,and the prob lems of traditional methods,including the superposition modes,cannot be effectively separated,the layouts of measuring points are complex,and the timing signals of excitation are difficult to measure in some cases,all of which have brought difficult identification for damping parameters.Starting with modal superposition meth od theory in dealing with multiple-degrees-of-freedom system dynamic response,the inversion theory for cal culating system modal damping was proposed by using the resonant frequency’s and its adjacent frequency’s excitation responses.The theoretical relationship between the response and the damping ratio was deduced,the concept of‘composite scale factor’was given,and it was also pointed out that if the difference between the system resonance response and the maximum response was ignored,the calculation results may suffer some significant deviation.In the case of a ship hull girder numerical calculation,the inversion theory of damping and its formula were validated combining standardization.Furthermore,they were generalized to 2D plane,the damping ratio tests of three different types of composite material local hull plate unit structure mod el were completed,and the damping performance of the composite materials was compared with that of steel,it was found that the composite materials have attractive application prospect in terms of depressing vibration and noise.The technical support for the total vibration damping estimation method of submarine and the dis tributed damping research is provided by this theory.

关 键 词：模态阻尼比识别 反演理论 共振激励 变频激励 船体梁 局部板单元 

分 类 号：TH212[机械工程—机械制造及自动化] TH213.3