In order to find out a handy and effective method in structural damage detection, model tests of a china disk, a steel shell and a five-storey steel frame structure were performed. Based on experiment results and Ohm's auditory law, musical tone law method ( MTLM) for structural damage detection was proposed. This method was effective for symmetrical structures in structural damage detection, such as, framed structure, cable structure, shell structure, and so on. It was clear that Fourier spectra of symmetrical structures are similar to those of musical tone according to the model tests. That was just the fundamental theory of MTLM. Model tests proved that MTLM is effective in detecting damage of the china disk and the radial damage of the steel shell; however, it is invalid for the circular damage of the steel shell, and the main cause is that the circular damage makes the stiffness of the steel shell decrease little; in the damage detection test of the five-storey steel frame structure, it is first time to use the frequency ratio as a diagnosis index in structural damage detection, and the damage is detected successfully.%为寻求一种简便、高效的结构损伤识别方法,组织实施了瓷盘、钢壳及5层钢框架的模型试验,根据试验结果,提出了一种基于欧姆听觉定律的结构损伤识别方法,即“乐音准则法”.该方法对于诊断均匀、规整的一维(杆、索)或二维(板、壳)结构的损伤十分有效.试验结果表明,均匀、规则结构的固有振动频谱具有与乐音相类似的特征,在其发生损伤后,固有振动频谱发生明显变化,据此定义了“乐音准则法”.试验证明,该方法对识别瓷盘损伤敏感有效;对钢壳径向损伤有效,对环向损伤不敏感,主要原因是环向损伤对壳体结构刚度影响较小.在5层钢框架的损伤识别试验中,根据乐音准则法,首次提出运用频率比作为结构损伤诊断指标,成功地识别出了结构损伤.
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