新型电液振动台振动参数的分析

Solution on Vibration Parameters of a New Electro-hydraulic Shaking Table

新型电液振动台采用具有双自由度的2D高频激振阀作为电液激振器,其驱动装置采用大功率、大扭矩的液压马达驱动阀芯的径向旋转,阀芯的轴向滑动用电机通过偏心轮机构来驱动。作者对高频激振阀阀口面积波形进行分析,根据已建立的数学模型采用分段积分的方法求解出振动波形的分段表达式,由此振动波形的解析解推导出振动幅值、工作频率、阀芯轴向位移以及阀芯转速之间的相互关系,在电液振动台上进行疲劳试验以验证解析结果的正确性。研究结果表明:加载模式以弹性负载为主的条件下,振动幅值的大小与阀芯的旋转速度成反比,与阀芯的轴向位移成正比,但是当阀芯位移达到某一临界值时,振幅由于压力饱和而不再继续增大,同时工作频率越大,考虑到实际机械设计及加工,振动波形越不容易出现饱和现象。

The two-dimensional valve （called as 2D valve） which has two degrees of freedom was used in a new electro-hydraulic shaking table as a vibration exciter, its drive device uses a high-power and large torque hydraulic actuator to drive the spool rotating and a motor to control the spool shafting. The valve ports area was analyzed, the expressions of excited waveforms were solved using the subsection integration method based on the mathematical model for deducing the relationship between the amplitude, working fre- quency, the valve＇s axial opening and rotational speed of the spool. The theoretical analysis results were validated by the electro-hydraulic vibration fatigue test. The results show that the amplitude of the excited waveform increases linearly with the valve＇s axial opening until it reaches a critical value and decreases as rotational speed of spool is increased under the condition of the load mode being elastic load. When working frequency is higher, the saturated phenomenon occurs difficultly because the practical mechanical design and operation can not assure meeting the critical value.