摘要
连接界面上多物理场、非线性等力学行为是引起复杂结构动力学的主要原因,会引起结构的刚度软化和幅变阻尼。利用Iwan模型描述连接界面黏滑摩擦行为引起的迟滞非线性特征,采用数值积分获得连接结构非线性力学行为影响的传递特征,将绝对加速度的传递特征转化为相对加速度的幅频和相频特征,进而辨识出连接结构随频率变化的等效刚度和阻尼特征,并且研究了不同激励幅值对连接界面非线性动力学行为的影响。结果表明:Iwan模型能够较好地描述连接面的刚度软化和幅变阻尼特征,随着激励幅值的增加,连接界面的动力学行为由微观黏着控制逐渐转化为宏观滑移控制,等效刚度逐渐下降,表现为结构刚度的非线性软化特征;等效阻尼在微观滑移阶段逐渐增加,但在宏观滑移阶段却有所下降,表现为幅变阻尼的特征。
The existence of multi-physics and nonlinear behaviors of the joint interfaces is mainly responsible for the complex dynamics of the assembled structure,resulting in the nonlinear softening stiffness and amplitude-varied damping characteristics.The Iwan model is used to describe the hysteresis nonlinearity induced by the stick and slip frictional behaviors of the joint interfaces.Numerical integration method is then used to simulate the frequency response functions of the absolute acceleration,which is then transformed into the amplitude and phase characteristics of the relative acceleration,and identify the equivalent frequency-varied stiffness and damping.The effects of external excitation amplitudes on the nonlinear dynamics of the joint interfaces are also investigated.The results show that the Iwan model can be used to characterize the nonlinear softening stiffness and amplitude-varied damping induced by stick and slip friction behaviors well.With the increase of the excitation amplitudes,the nonlinear dynamics of the joint interfaces dominated by the micro-stick behaviors will be gradually transformed into ones being dominated by the macro-slip,and the equivalent stiffness will also decrease,indicating the nonlinear softening stiffness.The identified damping will increase with the increasement of the excitation amplitude for the micro-stick regime,whereas the trend is reversed for the macro-slip regime,indicating the amplitude-varied damping.
作者
王东
范宣华
WANG Dong;FAN Xuan-hua(Institute of Systems Engineering,China Academy of Engineering Physics,Mianyang 621999,China;Shock and Vibration of Engineering Materials and Structures Key Laboratory of Sichuan Province,Mianyang 621999,China)
出处
《振动工程学报》
EI
CSCD
北大核心
2019年第6期1060-1066,共7页
Journal of Vibration Engineering
基金
国家重点研发计划(2016YFB0201004)
国家自然科学基金资助项目(11872059)
关键词
连接界面
迟滞非线性特征
黏滑摩擦
Iwan模型
软化刚度
joint interfaces
hysteresis nonlinear characteristics
stick-slip friction
Iwan model
softening stiffness
