摘要
本文提出了一种基于频率响应函数拟合模型的结构动力修改的分析方法。用有理分式正交多项式对测试频响作总体拟合,通过拟合频响作结构修改计算,这样既可较充分地计及分析频带外模态的效果,又能较好地抑制测试误差的影响。对悬臂梁加另一根悬臂梁变成两端固支梁的大修改情况作了计算机模拟计算,对 H 型梁的端部加一根梁的复杂修改问题作了全过程的分析。从结果来看,本文提出的方法精度较高,适用于大修改、复杂修改情况。
A procedure of structural dynamics modifications based on the fit model of frequency response functions(FRFs)is presented.A global curve fitting of measured FRFs using the rational fraction orthogonal polynomial isperformed.Then,the fit FRFs are used to predict structural modifications.Thus,not only the effects of modes outsideof their analysis bandwidth can be included,but also the pollution of test errors can be restrained.Two examples aredemonstrated.The first simulates the modification of a cantilever beam to a fix-fix beam,a very severe modification.The second,being a practical case,shows the modification of a beam added to an H-Frame,a complicatedmodification.The results show that the presented procedure can be applied to the cases of severe and/or complicatedmodifications,and the accuracy of the procedure is satisfactory.
出处
《振动工程学报》
EI
CSCD
1991年第3期18-26,共9页
Journal of Vibration Engineering
基金
国家自然科学基金资助项目
关键词
结构分析
频率响应
结构动力修改
structural analysis
substructural method
frequency response function
structural dynamics modification
