典型锥形结构两点响应控制试验研究

目的研究小长径比结构进行两点振动响应控制时的可行性,提升地面振动模拟真实性。方法针对一长径比约3:1的短圆锥结构,首先以圆锥表面气动载荷为振动输入载荷,通过数值仿真获得结构在自由状态下内部两点的加速度功率谱密度曲线,再采用激励杆和激励板的形式进行两点激励加载,控制要求的两点加速度响应。将真实响应的控制结果与常用梯形谱的控制结果进行对比,分析控制的有效性及结果的合理性。结果通过对比不同的两点激励加载部位,发现振动控制效果会存在明显差异,以仿真的结构响应作为振动控制谱,具有良好的振动控制效果,实际控制的功率谱密度曲线只在局部"谷"的地方和低频段出现超差,实际均方根值与要求均方根值差异较小。结论以仿真得到的结构内部响应作为振动控制谱,可以提高结构地面振动考核的真实性。当振动激励部位选择合适时,对于小长径比结构,也可以得到良好的控制效果。

Experimental Study on Two Points Response Control Technology for Typical Conical Structures

The multi-exciter vibration test method is suitable for the vibration loading of large and slender structures. The position of the control points are usually located near the excitation points and the control condition is a ladder spectrum obtained by the envelope method. This method may lead to an obvious difference between the response of test and the real response. Aiming at a short conical structure, this paper proposes a new experimental design method to control different responses of two points in the test structure. The acceleration power spectrum density of two points in the structure is obtained by numerical simulation. A two points excitation is used to control the two points response by using the excitation bar and the excitation plate. The test results show that the responses of the control points have reasonable correlation and the excitation position is reasonable. Therefore, the control effect is very well when the two points response control is carried out.