基于固有频率向量的结构损伤检测实验研究

EXPERIMENTAL INVESTIGATION OF STRUCTURAL DAMAGE DETECTION BASED ON THE NATURAL FREQUENCY VECTOR

引入固有频率向量及固有频率向量置信准则的概念,提出基于固有频率向量的结构损伤检测方法。以一个8层剪切框架模型的损伤检测为例,阐述用该方法进行损伤检测的原理和步骤。首先根据修正后结构的动力学模型,用局部刚度减小的方法,模拟结构不同位置和不同程度的损伤,计算出损伤结构序列的固有频率,并组成固有频率向量作为损伤数据库。然后实验测试出带损伤实物模型的固有频率,并组成固有频率向量,再根据该实测固有频率向量与损伤数据库中固有频率向量之间的固有频率向量置信准则,对损伤程度和位置进行检测。对框架结构的损伤检测实验结果表明,文中的方法可以准确地识别出损伤的位置,并可以较准确地检测出损伤的程度,而且实验结果证明文中方法还具有较强的抗测量噪声的能力。

Based on the fact that for structure with small damage, its natural frequencies will have some changes compared to its primary intact state, the concept of natural frequency vector is introduced and a new method to detect small damage of structure is prop- osed. The principle of damage detection method is described and an 8-story shear frame smleture is used to demonstrate the damage detection procedure. In the detection, the natural frequency veetor assurance criterion （NFVAC） is also intredueed and used as the damage index. The damage detection results show that based on the concept of natural fi：equency vector, the damage location and extents of the frame structure can be detected with good aceuracy and this method is robust to measuring noise.