Vibration-Based Structural Damage Detection: Theory and Applications

摘要结构的损伤可以定义为结构承载能力的降低，这可能是由于结构的部件和连接在其使用寿命期间的劣化造成的。提出的研究目标是开发和实验验证：1)一种鲁棒的迭代算法，可以使用最少的振动测量次数准确地检测小到大级别损伤的位置和程度；2)模态试验中随机冲击试验的新型随机模型和新型随机冲击装置。该迭代方法结合了一般阶多参数摄动法和优化法，仅利用前几个测量的固有频率就能准确地检测到照明桅杆等梁结构的损伤位置和程度。其他新特性包括病态系统方程的处理，通过以受控方式修改结构来丰富测量信息，基于物理的关节建模技术的发展，以及关节损伤检测。随机冲击试验可以结合单次冲击试验和振动筛试验的优点；它可以增加结构的能量输入，改善信噪比和测量的频响函数。利用随机冲击序列的随机模型，结构的输入能量可以分布在一个宽的或期望的频率范围内。随机冲击装置将比振动筛更轻、更简单、更容易使用；它也可以用来激发非常大的结构。协作

Abstract Damage in a structure can be defined as a reduction in the structure's load bearing capacity, which can result from deterioration of the structure's components and connections during its service life. The objectives of the proposed research are to develop and experimentally validate: 1) a robust, iterative algorithm that can accurately detect the locations and extent of small to large levels of damage using a minimum number of vibration measurements; and 2) novel stochastic models for the random impact test in modal testing and a novel random impact device. The new iterative method that combines a general-order, multiple-parameter perturbation method and an optimization method can accurately detect the locations and extent of damage in beam structures such as lighting masts using only the first few measured natural frequencies. Other new features include treatment of ill-conditioned system equations, enrichment of the measurement information by modifying the structure in a controlled manner, development of physically-based joint modeling techniques, and joint damage detection. The random impact test can combine the advantages of the single-impact test and the shaker test; it can increase the energy input to the structure, and improve the signal-to-noise ratio and the measured frequency response function. With the stochastic models for the random impact series the input energy to the structure can be distributed in a wide or desired frequency range. The random impact device will be lighter, simpler, and easier to use than a shaker; it can also be designed to excite very large structures. Collaboration