Department of Civil Engineering & State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, China.
Department of Civil Engineering, Dalian Minzu University, Dalian 116650, China.
Sensors (Basel). 2019 Jan 16;19(2):340. doi: 10.3390/s19020340.
Adding virtual masses to a structure is an efficient way to generate a large number of natural frequencies for damage identification. The influence of a virtual mass can be expressed by Virtual Distortion Method (VDM) using the response measured by a sensor at the involved point. The proper placement of the virtual masses can improve the accuracy of damage identification, therefore the problem of their optimal placement is studied in this paper. Firstly, the damage sensitivity matrix of the structure with added virtual masses is built. The Volumetric Maximum Criterion of the sensitivity matrix is established to ensure the mutual independence of measurement points for the optimization of mass placement. Secondly, a method of sensitivity analysis and error analysis is proposed to determine the values of the virtual masses, and then an improved version of the Particle Swarm Optimization (PSO) algorithm is proposed for placement optimization of the virtual masses. Finally, the optimized placement is used to identify the damage of structures. The effectiveness of the proposed method is verified by a numerical simulation of a simply supported beam structure and a truss structure.
向结构中添加虚拟质量是生成大量自然频率以进行损伤识别的有效方法。虚拟质量的影响可以通过虚拟变形法（VDM）使用传感器在相关点测量的响应来表示。适当放置虚拟质量可以提高损伤识别的准确性，因此本文研究了其最佳放置位置的问题。首先，建立了添加虚拟质量后的结构的损伤灵敏度矩阵。建立了灵敏度矩阵的体积最大准则，以确保测量点的相互独立性，从而实现质量放置的优化。其次，提出了一种灵敏度分析和误差分析的方法来确定虚拟质量的值，然后提出了一种改进的粒子群优化（PSO）算法用于虚拟质量的放置优化。最后，利用优化后的布置来识别结构的损伤。通过对简支梁结构和桁架结构的数值模拟验证了所提出方法的有效性。
