Damage Identification of Semi-Rigid Joints in Frame Structures Based on Additional Virtual Mass Method

Abstract

In civil engineering, the joints of structures are complex, and their damage is generally hard to be detected. Due to the insensitivity of structural modal information to local joint damage, this paper presents a method based on additional virtual mass for damage identification of a semi-rigid joint in a frame structure. Firstly, the modeling of a semi-rigid is described. Secondly, the frequency response of the virtual structure is constructed, and the natural frequency of the constructed virtual structure is extracted by the ERA method. By adding multiple values of virtual masses at different positions, the natural frequency information sensitive to joint damage for damage identification is effectively increased. Based on the above theory, qualitative identification of joint damage is proposed to detect the potential damage, and identification of both damage location and its extent is presented, using natural frequency. Improved Orthogonal Matching Pursuit (IOMP) algorithm is employed to improve the accuracy of the natural frequency-based method for damage identification. At last, numerical simulation of a three-story frame is performed to discuss and to verify the effectiveness of the proposed method.

Structural damage identification method based on Swin Transformer and continuous wavelet transform

“…For example, Daneshvar et al developed a new modal strain energy sensitivity function to improve damage detectability, and successfully localize and quantify damage under incompletely noisy modal data [4] . Pooya et al used the absolute difference of modal strain energy coefficients as an indicator of damage location and applied the relationship between modal strain energy and modal kinetic energy to identify the damage of beam [5] . An et al proposed a damage identification method for semi-rigid joints in frame structures based on additional virtual mass, which utilizes natural frequencies to identify the location and extent of damage [6] .…”