【摘要】 针对随机减量技术应用过程中有关触发条件的选择问题进行了详细的分析,对随机减量函数进行了相应的扩展,并且在传统的水平穿越触发条件的基础上,又提出了零穿越触发、极值点触发和随机采样触发三种简单实用的触发条件,克服传统触发条件对于触发点数和截取幅值的局限,拓宽了随机减量技术的应用范围。通过实际的数值算例及其进行模态参数识别的应用,验证了几种触发条件的实用性,计算结果表明,对于实际采样信号长度有限或响应幅值较小的情况下,上述提出的方法比传统方法能得到更理想的效果。更多还原

【Abstract】 Triggering condition is a very important requisite for random decrement technique in random signal analysis.The general triggering condition is discussed in detail and an extended random decrement function is put forward based on a more general triggering condition.Because the traditional threshold level crossing triggering condition is limited due to the number of triggering points and the crossing threshold value,three simple and effective triggering conditions are presented and they make use of random decrement technology more widely.Especially,the proposed methods are effective in the condition that the length of the sampled signal is limited or the amplitude of the response signal is small.A numerical example and the structural modal identification based on random decrement signals are presented to verify the usability of the proposed methods.更多还原