脉冲锤击的传递函数计算方法研究

A study on the transfer function estimation algorithms of impulse hammer excitations

由于锤击激励跟响应的时间对应关系以及系统的非线性因素在传递函数计算中很难考虑,导致传递函数的估计误差很大。本文在选择合适的传递函数计算公式基础上,充分考虑激励信号与响应信号时间对应关系,建立了多次激励平均的脉冲锤击传递函数计算方法,并结合锤击激励信号、响应信号各自的自谱及它们的相干函数,确定出传递函数线性有效可用频段,使得脉冲锤击传递函数的估计更加系统和完善。另外仿真实验验证了此传递函数估计方法具有较高的估计精度。此方法的建立对于舰艇振动噪声传递的定量分析具有重要意义。

In the process of transfer function computation, it is difficult to consider the time corresponding relation between hammer impulses and responses, as well as the nonlinear factors of system, which leads to a large estimation error of the transfer function. Based on the appropriate selections of the transfer flmction formula, and sufficient considerations of the corresponding relation between the hammer impulses and the responses, a novel estimation method of the impulse hammer transfer function is proposed in this paper by averaging multiple excitations. Combined with the respective auto-spectrum and coherence function of the hammer impulses and the responses signals, the effective linear frequency bands are determined. The proposed method makes the estimation of the impulse hammer excitation transfer functions much more systematic, and perfect. The estimation method of transfer function possesses a higher estimation precision through simulation experiments. And it also possesses an important significance for the quantity analyses of naval ship vibration-noise-transfers.