Development of a two-stage method based on optimization algorithms and smart calculation methods in structural damage detection

Subject Areas : Analysis of Structure and Earthquake

Behrouz Safa ¹ , Asghar Rasouli ² , Yahya Nasira ³

1 - Department of Civil Engineering, Zanjan Branch, Islamic Azad University, Zanjan, Iran
2 - Department of Civil Engineering, Zanjan Branch, Islamic Azad University, Zanjan, Iran
3 - Department of Civil Engineering, Zanjan Branch, Islamic Azad University, Zanjan, Iran

Received: 2023-02-17 Accepted : 2023-06-10 Published : 2023-07-03

Keywords: Optimization algorithm, Smart calculation methods, Structural damage detection,

Abstract :

Among the countless methods that have been proposed in the field of structural damage detection, the finite element model updating method has been very popular. However, the accuracy and efficiency of this method decrease drastically when the number of variables in the problem increases, and this is a problem when dealing with large structures with a large number of elements. In this research, a two-step method is proposed, which is capable of reducing the size of the damage detection problem introduced to the updated model by identifying damaged structural members through a damage index based on static strain energy in the first step. Therefore, only a few variables are introduced to the second step, which include a process of updating the finite element model. This second step actually consists of an iterative process of updating the model, which uses a new and damage-sensitive objective function to detect the severity of damage in the elements identified in the previous step. Also, a meta-exploratory optimizer named equilibrium optimizer is utilized to determine the value of the unknown variables of the problem, which are the damage values ​​of the elements introduced by the first step. The proposed method has also been tested on a number of numerical samples to check the effectiveness of the method in the presence of external disturbing factors such as measurement noise. A comparative study has been done to compare the results. According to the results, the proposed method is able to detect the location and severity of damage in different structures, and measurement noises and modal information only from the first few vibration modes do not have much impact on the accuracy of the results. A laboratory study has also been conducted to find out the efficiency and accuracy of the proposed method in real structures, and according to the results, the proposed method is well able to detect damage.