多点随机振动试验的最小驱动

对大尺寸的结构、系统随机振动试验采用多点控制已成为必然趋势.在计算多点控制驱动的时候,如果已知多个控制点参考互功率谱密度矩阵,应用矩阵方程的最小范数最小二乘解,固然可以求出满足此条件的最优驱动,但是对于多点随机振动环境试验,目前限于实测数据的限制,很多情况下试验仅定义了控制点的自功率谱密度,没有定义各点之间的互功率谱密度,本文中在已知各点的自功率谱和频率响应特性下,应用矩阵的广义逆,推导出了驱动功率的最大值和最小值,并给出了多输入多输出的仿真算例.

Minimum drive power of multiple-point random excitation test

A technique for control of random vibration test where excitation is applied at two or more points is required for large size and complex structure test item.Multiple-point random excitation test requires the specification of the auto-spectral density and the cross-spectral density. However,the cross-spectral density of motion between each pairs of controls is not offered in some tests,in the case of knowing the frequency-respond character,and hence the maximum and minimum drive power formula with using the generalized matrix inverse are deduced. A simulation is also made in this paper.