基于频响函数计权的Z振级计算方法

The weighting method of Z-vibration level computation based on frequency response function

计权Z振级是环境振动评价的重要指标量。针对现有的基于倍频程的计权方法通常计权计算的效率较低或者低频段计权误差较大的问题,提出一种基于频响函数的计权方法。首先,将ISO 2631-1—1997标准中给定的计权联合滤波器转换为频率响应函数。然后,根据结构动力学中的单输入-单输出模型,将计权前的振动加速度作为该频响函数的输入,得到SISO模型的输出为计权加速度。该方法避免了倍频程的计算需求,有效地提高了计算效率。最后,通过仿真和实际测试算例验证了提出的方法准确性和有效性。

The weighted Z-Vibration Level(VLz)is an important indicator in the evaluation of environmental vibration.At present,however,several of the weight methods involve a time-consuming calculation and are less efficient.Additionally,using these methods may introduce larger errors when calculating the one-third octave in a low-frequency band.Therefore,a new method for computing the VLz by weighted acceleration based on the frequency response function(FRF)is proposed in this paper.First,the FRF of a single input single output(SISO)model is constructed with the weighting network which is given in the ISO document 2631-1—1997.Then,the weighted acceleration is the output of the SISO model obtained by the measured acceleration and the FRF.Thus,the method improves the computational efficiency by avoiding the conversion of one-third octave range.A simulation and a practical test case are applied to validate the accuracy and efficiency of the proposed method.The results show that the new method has good precision and effectiveness.