多点复杂载荷作用下结构振动仿真与试验研究

Simulation and tests for vibration of structures under multi-point complex loads

多点复杂载荷激励作用下舰船等结构的振动响应问题是进行声辐射问题求解的前提。以安装于基座面板上的激振电机作为激振源,振源与基座面板通过力传感器进行多点连接,分别使用力传感器和加速度计测量激振电机运转时输入至结构的激振力和安装点处的加速度值。采用MATLAB和LabVIEW两种编程语言混合编程,考虑相位差的影响,结合有限元法获取的传递函数,对多点激励下的振动响应进行仿真和试验研究。并探讨了结构在力型输入和加速度型输入条件下,多点激振的振动响应求解方法,试验研究的结果验证了多点激振时传递函数理论计算结果的正确性。对比研究结果表明采用力型输入所得结果与实验结果符合最好,且影响加速度型作为输入条件求解振动响应精度的因素多,并非参与运算的通道越多所得结果越好。

Warships’ sound radiations under multi-point complex loads are based on their structures’ vibration responses. Here,an exciting motor was installed on a warship’s base plate as a vibration excitation source. This vibration source was connected with the base plate at multiple points through force sensors. Force sensors and accelerometers were used to measure exciting forces inputted from the motor to the warship’s structure and accelerations at installation points,respectively. A program coded with MATLAB and LabVIEW was developed to calculate the warship’s structure vibration responses under multi-point complex excitations considering effects of phase differences among inputs and combining with the vibration transfer function obtained using the FE method. On the other hand,the multi-point excitations and the warship structure vibration responses were also measured in tests. Furthermore,the theoretical solving methods for structure’s vibration responses under multi-point excitations were explored in cases of force type of excitations and acceleration type ones,respectively. The test results verified the correctness of the theoretical calculation ones using the vibration transfer function. It was shown that the theoretical calculation results with force type of excitations agree best with those of tests; factors affecting the accuracy of solving vibration responses under acceleration type of excitations are many,more channels involved in computation do not always cause better results.