非线性吸振器的靶能量传递及参数设计

摘要

首先通过研究两个非线性耦合振子,阐明了非线性吸振器具有对初始能量的选择性.即吸振系统在一定带宽的初始能量(主结构中初始能量的大小)下具有很强的吸振能力,而随初始能量偏离一定值,吸振器耗散能量的能力有所减弱.随后提出,在不增加吸振器质量的前提下,采用两自由度的非线性吸振器不仅可以使得能量在吸振器中的耗散加快,靶能量传递效果更好,而且在保证吸振效率的同时,吸振器对于初始能量的有效带宽显著增加.给出了两自由度非线性吸振器的质量、阻尼、刚度等参数的设计方法,最后采用数值仿真验证了上述结论.%Through a research on two coupled nonlinear oscillators, a mechanism is clarified that for a nonlinear vibration absorber, the initial energy of the main structure is highly selected.Energy dissipation in a nonlinear vibration absorber is highly effective with a specific amount of initial energy, but the efficiency of energy dissipation is weakened as the initial energy deviates from that specific value.In other words, the single degree-of-freedom nonlinear vibration absorber will be less effective if the energy of the main structure is not within a certain interval.It is proposed that by using a well designed two-degree-of-freedom nonlinear vibration absorber, a more effective targeted energy transfer can be achieved.Using a two-DOF unequal mass nonlinear vibration absorber, dissipation of vibrational energy becomes more effective and bandwidth of energy absorption increases significantly.What's more, the two-DOF nonlinear vibration absorber doesn't necessarily be heavier than the one-DOF absorber.The method for determining the mass and stiffness of the nonlinear vibration absorber is given.The above analysis is verified by numerical simulations.