结构密集模态非线性耦合作用引起的线性模型失效问题研究  

STUDY OF THE LINEAR MODEL EFFICIENCY WHEN NONLINEAR COUPLING EXISTING WITH CLOSELY SPACED NATURAL FREQUENCIES

作　　者：白鸿柏[1] 郑坚[1] 张培林[1] 陈振藩[2] 

机构地区：[1]军械工程学院兵器工程系,石家庄050003 [2]南京航空航天大学,南京210016

出　　处：《机械强度》2000年第4期300-302,306,共4页Journal of Mechanical Strength

基　　金：国家自然科学基金!(1 9372 0 2 4 );航空基金!(94B52 0 1 0 )

摘　　要：通过对两自由度密频近线性系统主共振响应的分析 ,研究了结构密集模态弹性非线性耦合作用引起的一些典型的非线性动力学现象 ,如幅频曲线弯曲、Hopf分叉导致的概周期响应。研究结果表明 ,存在密频内共振时 ,线性模型失效 。By the analyzing principal resonance of a tow degree of freedom nearly linear system with closely spaced natural frequencies, some typical nonlinear kinetic phenomena such as sophisticated bending in the frequency response curve, almost periodic response due to Hopf bifurcation caused by the structural modes nonlinear coupling with closely spaced natural frequencies were studied. And an important conclusion is that when IRCF (internal resonance due to closely spaced natural frequencies) exists, a relatively large fraction of the total energy stored in the system inputted by excitation will transmit from the directly forced model into the unforced one under parameter excitation, so a linear model can not be used and a nonlinear one should be adopted for this case to describe structural kinetic characteristic.

关 键 词：非线性振动 密频内共振 密集模态 线性模型失效 结构 

分 类 号：O342[理学—固体力学] O322[理学—力学]