Journal of Steel & Structure

Journal of Steel & Structure

Health monitoring of existing steel frame buildings with semi-rigid saddle connections using finite element model updating method

Document Type : Original Article

Authors
Amir Zayeri Baghlani Nejad 1
Mohammad Shokrollahi 1
Mussa Mahmoudi Sahebi 2
1 Faculty of Civil Engineering, Jundi-Shapur University of Technology, Dezful, Iran
2 Faculty of Civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
10.22034/jss.2025.549837.1008
Abstract
Although the use of saddle connections in steel structures has largely declined in Iran due to technical limitations, many significant buildings across the country were constructed using this method in the past. Ensuring the maintenance and structural health monitoring of these aging frameworks remains a critical concern. This study focuses on identifying dynamic characteristics and evaluating the integrity of steel frame structures with semi-rigid truss connections. One of the key challenges in this area is accurately modeling truss connections in finite element software. To address this, we propose a refined approach for finite element modeling of such structures. The model is then calibrated and updated using dynamic vibration data obtained from environmental loads, ensuring the closest possible representation of the real structure. The updated model is applicable in various scenarios, including post-incident damage assessment, structural optimization, reinforcement planning, and ongoing health monitoring. To validate the proposed methodology, a real three-story structure was examined through vibration tests. The prepared finite element model was updated accordingly, and analysis of the results demonstrated strong agreement between the model's dynamic characteristics and the actual structure, affirming the effectiveness of the proposed approach.
Keywords
Semi-Rigid Saddle Connection
Finite Element Model Updating
Vibration Test
Noise
Subjects
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  • Receive Date 28 September 2025
  • Revise Date 18 December 2025
  • Accept Date 06 January 2026
  • First Publish Date 06 January 2026
  • Publish Date 22 December 2025