【摘要】 为进一步明确乐音准则法的适用范围并提出相对应的量化的判伤标准,提高其应用性,选取了钢杆、钢框架及两组钢壳体模型进行了损伤识别实验,并综合其他符合乐音特征结构的频谱信息进行分析。结果表明:乐音准则法在判别构造简单、均匀规整的杆、索、板、壳类结构的损伤时有效;其频谱分布规律为各个谱线呈"梳齿状"展布,清晰有序,各阶频率按照一定规律分布;可以通过将各阶频率对应其模态阶数作为散点来拟合直线或者对数(指数)曲线的方法来判别损伤,将这种分布规律称为乐音准则法的数学表达。并由此提出乐音准则法的判伤步骤,该方法优点在于可以在没有完好结构作为损伤判别指标时进行损伤识别。更多还原

【Abstract】 In order to consider the application range of the musical tone law methods and get the corresponding index to identify the existence of damage in structure,model tests of steel pipes,steel shells and a three-storey steel frame structure were performed. And the frequency spectra of other structures,in which the vibration rules obey the musical tone law was also outlined. The analysis results show that the musical tone law was effective for symmetrical structures in structural damage detection,such as,plates,cable structure,shell structure and beam. And the spectrum distribution rule of intact structure is also proved. The spectral lines are distributed like comb teeth according to certain laws. The damage can be identified by the exponential or logarithmic function curves of the structural spectrum. In this thesis,the mathematical expressions of musical tone law and steps using the method for structural damage detection is proposed. The merit of the method is that it can be used for damage detection without an intact structure as a criterion.更多还原