对称轨道型单侧碰撞非线性能量阱的振动抑制

Numerical study of vibration suppression of a symmetric single-sided vibro-impact track nonlinear energy sink

针对轨道型单侧碰撞非线性能量阱的振动抑制性能受载荷方向影响较大的问题,本文提出一种对称轨道型单侧碰撞非线性能量阱。利用质量块沿着一侧放置有碰撞表面的特定轨道运动时产生的光滑与非光滑非线性回复力与主结构进行动力学耦合,实现系统中能量的耗散,进而降低结构的动力学响应。建立带有对称轨道型单侧碰撞非线性能量阱系统的动力学模型,通过数值仿真的方法分析了对称轨道型单侧碰撞非线性能量阱参数变化(质量,轨道形状)对振动抑制性能的影响。在选取最优的质量和轨道形状参数之后,通过时域和小波变换分析了系统中能量耗散及能量从低频振动向高频振动转移现象,分析了对称轨道型单侧碰撞非线性能量阱设计参数差异对其性能的影响。结果表明:对称轨道型单侧碰撞非线性能量阱能够有效抑制冲击载荷作用下结构动力学响应,且其对设计参数的差异具有较强的鲁棒性。

Considering that the vibration suppression performance of the single-sided vibro-impact track nonlinear energy sink(SSVI track NES)is greatly affected by load direction,we propose a symmetric,single-sided vibro-impact track nonlinear energy sink(SSSVI track NES).Both smooth and non-smooth nonlinear restoring forces are produced when the mass is moving on the specific track with a single-sided impact surface.This nonlinear restoring force achieves the dissipation of energy in the system through dynamic coupling with the primary structure,thereby reducing the dynamic response of the structure.The equations of motion of a single degree of freedom oscillator with an SSSVI track NES are established.The influence of the parameters of the SSSVI track NES(mass,track shape)on vibration suppression performance is discussed through numerical simulations.Optimal NES mass and track shape are obtained and applied to a time domain and wavelet analysis.Energy transfer phenomena from a lower frequency vibration to a higher frequency vibration is observed.The effect of the SSSVI track NES design parameter differences on its performance are discussed.The results demonstrated that the optimized SSVI track NES is effective in suppressing the shock response of the structure,and is robust to the differences in design parameters.