基于形函数方法快速识别结构动态荷载的试验验证

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振动与冲击 ›› 2011, Vol. 30 ›› Issue (9) : 98-102.

论文

基于形函数方法快速识别结构动态荷载的试验验证

张青霞1,3,4; 段忠东2,3; Łukasz Jankowski4

作者信息 +

Experimental validation of a fast dynamic load identification method based on load shape function

Zhang Qing-xia1,3,4; Duan Zhong-dong2,3; Łukasz Jankowski4

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文章历史 +

摘要

在动态荷载识别中常常由于矩阵的病态性影响识别的精度，利用有限元理论中的形函数逼近荷载曲线，将识别离散的荷载历程转化为计算有限的形函数权重，从而显著改善反卷积法识别荷载中存在的采样时间长或采样频率高时数值求解困难的问题；并能改善反问题的病态性，提高对噪音的鲁棒性。一个连续梁的数值算例比较验证了该方法在5%的高斯噪声影响下能精确地识别未知荷载。悬臂梁试验中，通过实测的结构动态响应，在移动时间窗内利用荷载形函数方法可以实现激励的在线识别。

Abstract

A dynamic load identification method was introduced and complemented, in which the force was approximated using the shape functions from the finite element theory. The computational work is deduced a lot by calculating the weights of shape functions instead of indentifying the discrete load time history. It improves the performance of the deconvolution method in a long sampling time or high sampling frequency. Moreover, it improves the ill-conditioning of the inverse problem, and increases the robustness to noise. A numerical continuous beam compares and verifies that the load can be identified precisely by this method with 5% Gaussian noise pollution. In a cantilever beam experiment, via the measured structural responses, this method enables the online load identification which is performed repeatedly in a moving time window.

导出引用

张青霞;; 段忠东; &#;ukasz Jankowski . 基于形函数方法快速识别结构动态荷载的试验验证[J]. 振动与冲击, 2011, 30(9): 98-102

Zhang Qing-xia;; Duan Zhong-dong; &#;ukasz Jankowski. Experimental validation of a fast dynamic load identification method based on load shape function[J]. Journal of Vibration and Shock, 2011, 30(9): 98-102