周期结构空腹梁的动态特性研究

设计了一种内部周期性挖空的梁，它在中高频具有良好的带通和带阻特性，带阻频率范围内的弹性波不能传播。空腹梁由周期单元串联而成，把周期单元分解成薄梁和刚性联接杆等子结构，推导了Timoshenko梁纵向、弯曲振动导纳，给出了刚性联接杆振动导纳，利用传递矩阵法计算得到了周期结构空腹梁的力传递率和带隙位置。数值模拟计算表明，当激励频率在周期结构的阻带之内时，周期结构空腹梁上的位移响应和传递到基础的力响应将大大衰减。

Analysis on dynamic characteristics of periodic hollow beam

A hollow beam, whose internal is periodically excavated, is designed to gain excellent band-pass and band-stop characteristics in the mid and high frequency domain. The hollow beam is composed of two Timoshenko beams periodically connected by n rigid joints. Longitudinal vibration mobility of rod and bending vibration mobility of Timoshenko beam are derived, vibration mobility of rigid joints are given. Force transfer rate and frequency of band gap are calculated by transmission matrix method. Numerical simulation result shows that displacement response of the periodic hollow beam and the force transmitted to the constraints of the beam will be greatly attenuated when the excitation frequency is located within the stop-band of the periodic hollow beam.