运用波传播和子结构技术检测结构损伤

Detection of Structure Damage Using Wave Propagation and Substructure-Based Method

提出了一种基于波传播和子结构技术来检测大型周期结构损伤的方法。分析了存在单一扰乱单元的有限周期结构的自由波传播 ,讨论了单元柔度变化对结构自振频率变化的敏感性。通过求解敏感性方程 ,用测得的自振频率的变化检测了大型周期结构的损伤位置和程度 ,并通过与子结构方法的结合 ,进一步提高了大型周期结构损伤检测的准确性和计算效率。对周期弹簧—质量结构损伤识别的数值结果说明 ,该方法不仅对结构损伤的位置和大小能够作出良好地预测 ,而且不需要知道未损伤结构的原始信息 ,只需要测得结构损伤前后的少数几个自振频率的变化 。

An approach based on wave propagation and substructure to detect the structural damage of large periodic structures is presented in this paper.The wave propagation method is adopted to analyze the free vibration of a finite periodic structure with a single disorder,and the sensitivity of the natural frequencies to the change in flexibility of element has been conducted.The locations and extent of the damage in large periodic systems have been identified by solving a set of underdetermined equations based on the sensitivity matrix.A substructure-based method for improving the computational efficiency and the accuracy of damage detection of large periodic structures has also been introduced.Numerical results of a periodic mass-spring-structure show that the proposed method can provide good predictions about both the locations and extent of the damage at one or more sites with high computational efficiency.Furthermore,the proposed method is particularly attractive in practice,in which priori information about the properties,such as stiffness of the undamaged structure,is not needed,and only the measurements of the differences in a few natural frequencies between undamaged and damaged structures are required.