Abstract
With the increase of bridge service life, various loads, environmental corrosion and material aging may lead to the accumulation of structural damage, it is significant to identify structural damage to provide maintenance strategies and prevent collapse accidents. A bridge damage identification method based on fused multi-point deflection influence line area is proposed in this study. Initially, the variational mode decomposition (VMD) technique is introduced to decompose the structural dynamic deflection under moving load, which will separate the dynamic fluctuation disturbance component from the structural low-frequency deflection response. In order to reduce the number of unknown variables to be solved and smooth the local fluctuations in the solution caused by noise, the Bspline basis functions are used to expand the influence line, which will transform the identification of influence line into solving the weight coefficients of base functions. Subsequently, the influence lines of the simply supported bridge before and after damage are derived, and a damage index based on the area difference of influence lines of fusing multipoint is proposed. Finally, a numerical simulating and experimental testing under various damage cases are studied to validate the feasibility of the proposed method. The dynamic fluctuation interference can effectively eliminate and the influence line can be accurately identified by proposed method. The fused damage index can effectively identify and localize structural damage under various damage cases, and the identification result is better and more stable than the damage index of single measurement point.
Address
(1) Chao Wang, Han Zhang, Xiang Pan:
School of Civil Engineering, Architecture and Environment, Key Laboratory of Health Intelligent Perception and Ecological Restoration of River and Lake, Ministry of Education, Hubei University of Technology, Wuhan 430068, China;
(2) Wen Yu He:
College of Civil Engineering, Hefei University of Technology, Hefei 230009, China;
(3) Wei Xin Ren:
College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060, China.
Abstract
Identifying damage at an early stage is crucial for preserving the integrity of structures. Damage in structures often manifests as adverse changes within the system, which can propagate over time and ultimately lead to structural failure. This research introduces a novel damage index, referred to as the P-Index, for detecting damage in beam-type structures. The P-Index is developed using the Reduced Interference Distribution—a bilinear timefrequency function—along with matrix expansion techniques. To validate the effectiveness of the proposed method, laboratory tests were conducted on a steel beam. The results demonstrate the capability of the P-Index to accurately identify damage. Key advantages of this method include high accuracy, ease of implementation, no requirement for input force measurement, reduced sensor usage, and the ability to work with recorded signals without noise removal.
Key Words
beam-type structure; damage index; matrix development method; time-frequency function
Address
(1) Hamid Reza Ahmadi:
Department of Civil Engineering, Faculty of Engineering, University of Maragheh, Maragheh 55136-553, Iran;
(2) Sherko Karimpour:
Department of Civil Engineering, University of Kurdistan, Sanandaj, Iran.
Abstract
This study proposes a multitask learning (MTL)-based framework for the integrated prediction of key structural performance parameters in steel–concrete composite deck slabs, including mid-span deflection and residual fatigue life. Traditional single-task approaches focus on isolated performance indicators and fail to capture the complex nonlinear interactions among design variables and the inherent coupling between structural responses. To address these limitations, a comprehensive hybrid dataset of 152 validated records was compiled by integrating experimental data, finite element analysis (FEA) simulations, and design-code-based augmented data. Input variables were standardized and optimized through feature importance analysis, and a multitask artificial neural network (MT-ANN) was developed to simultaneously predict both target outputs.
The model performance was benchmarked against established machine learning algorithms including Random Forest, XGBoost, Support Vector Regression, and Long Short-Term Memory networks. The proposed MT-ANN consistently outperformed single-task baselines in accuracy and generalization. SHAP-based interpretability analysis further revealed that geometric parameters and material properties contribute differently across prediction tasks, confirming the value of the multitask architecture.
The findings demonstrate that multitask learning provides a robust and scalable solution for holistic assessment of composite deck structural performance. The developed model supports structural design optimization, service life evaluation, and predictive maintenance planning. Its compatibility with digital twin and BIM-integrated environments further enhances its potential for real-time structural health monitoring in modern infrastructure systems.
Abstract
To improve the frequency sensitivity of a single tuned mass damper (TMD) and solve the complexity for multiple tuned mass dampers (MTMD) to determine the control mode and the effective number of TMDs, a new type of MTMD, namely rocking wall tuned mass dampers (RW-TMDs), is proposed in this paper based on the structural characteristics of rocking wall and the damping principle of TMD. To prove the effectiveness of RW-TMDs, theoretical analysis and numerical simulations were used to compare the damping effects of uncontrolled structures and controlled structures with TMD and RW-TMDs, respectively, under Gaussian white noise and different earthquake excitations. The results show that the RW-TMDs arranged along the height of the structure can effectively alleviate the frequency sensitivity of TMD, significantly reducing structural peak and root mean square value of acceleration and displacement. Besides, RW-TMDs with advantages of rocking wall structure can control inter-layer deformation mode and prevent the occurrence of layer collapse mechanism, efficiently. Furthermore, the RW-TMDs can mitigate structural damage degree by increasing the damping energy dissipation and reducing the plastic energy dissipation. Therefore, the RWTMDs have a high potential in practical applications for vibration control of building.
Key Words
energy dissipation; numerical simulation; rocking wall tuned mass damper; theoretical analysis; vibration control
Address
(1) Hang Yin:
College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060, China;
(2) Wei Nie, Ke Xu:
School of Management Science and Engineering, Henan University of Economics and Law, Zhengzhou 450046, China;
(3) Songlin Wang, Tianbao Liang:
China Construction Eighth Engineering Division Rail Transit Construction CO., LTD, Zhengzhou 450046, China;
(4) Runze Zhang:
Civil Engineering and Architecture Institute, Zhengzhou University of Aeronautics, Zhengzhou 450046, China;
(5) Shuxian Liu:
Department of Civil Engineering, Liaoning Technical University, Fuxin 123000, China.
