复杂结构振动响应预示的能量方法

摘要

针对复杂结构的振动响应分析,利用弹簧质量系统对模糊结构进行建模,建立了带有附加模糊结构的杆和梁的运动控制方程,在此基础上,进一步推导了能量密度的控制方程,以能量密度为输出响应进行了结构振动的仿真分析.仿真结果显示,模糊结构对结构振动能量密度响应的影响在其固有频率附近最大,这种影响通过模糊结构产生的随频率变化的等效质量实现,在模糊结构固有频率以内的低频域,等效质量为正,降低了结构振动的能量密度响应,在高于固有频率的频域内,等效质量为负值,使得结构的能量密度响应增大.%Rod and beam with fuzzy structures is modeled using sprur~g mass system to analyze vibro-acoustic responses of complex structures. Energy density is used as response method to .simulate the structural vibra- tion, and the simulation indicates that the fuzzy structures affect the master structure maximally around the nat- ural frequency of the fuzzy structures. The ~ff'ect acts as a frequency dependent equivalent mass. The equiva- lent mass is positive under the natural frequency of the fuzzy structure and negative over the frequency. The positive equivalent mass decreases, while the negative one increases the vibration energy density responses.