区间参数结构平稳随机载荷识别方法

Load identification of interval parameter structures under stationary random loadings

针对贫信息下不确定性结构的随机载荷识别问题,使用基于Taylor展开的区间分析方法,提出了一种不确定性结构随机载荷识别的非概率区间方法。该识别方法在频域中进行,识别时使用区间变量描述工程结构中的不确定性参数。基于测点的响应谱密度函数,首先对不确定性参数的名义值点进行随机载荷识别,其次计算载荷关于不确定性参数的灵敏度,最后基于区间扩张理论获得识别载荷谱的上下界值。算例结果表明,使用区间方法得到的不确定性结构的载荷谱识别区间界值都能完全包含载荷真值,此方法能够在结构设计时给出更为可靠的载荷工况。

A non-probabilistic interval method for random load identification of uncertain structures is proposed by using the interval analysis method based on Taylor expansion for the random load identification problem of uncertain structures with poor information.The identification is carried out in the frequency domain,using the interval variable to describe the uncertain parameters in the engineering structure.Based on the response spectral density function of the measured point,the nominal value of the uncertainty parameter is first subjected to random load identification.Secondly,the sensitivity of the load is calculated for the uncertainty parameter.Finally,the upper and lower bounds of the load spectrum are obtained based on the interval expansion theory.The results show that the interval of the load spectrum of the uncertain structure obtained by the interval method can completely cover the true value of the load.This method can give a more reliable load condition when a structure is designed.