Paper Contents
Abstract
ABSTRACTSteel scaffolds are critical temporary structures used for maintenance and construction on offshore oil and gas platforms. These scaffolds are frequently exposed to fluctuating wind loads, yet their susceptibility to dynamic buckling under periodic harmonic excitation remains poorly characterized in existing design frameworks. This study presents a comprehensive numerical simulation of the dynamic buckling behavior of steel scaffolds subjected to sinusoidal offshore wind loads using a MATLAB-based time-domain solver. The scaffold is idealized as a damped single-degree-of-freedom (SDOF) system, incorporating mass, stiffness, and viscous damping representative of offshore deployment conditions. The analysis revealed that, the peak lateral displacement reached about 15.0 mm, exceeding the scaffolds safe deformation threshold of 5-10 mm, thus indicating a clear buckling risk. The accumulated strain energy peaked about 30.0 J. Damping dissipated about 18.0 J of energy, underscoring its crucial role in moderating the systems vibration amplitude. Additionally, the amplitude-to-load ratio (ALR) rose to 0.042 mmN. The load-displacement trajectory revealed pronounced softening behavior, consistent with nonlinear geometric effects during large deformations. These results demonstrated that dynamic buckling, particularly under harmonic wind loading near resonance, poses a substantial failure risk for offshore scaffolding. Static analysis alone is insufficient for safety assurance. The developed simulation framework provides a predictive tool for identifying dangerous excitation frequencies and guiding safer scaffold design and deployment. This work contributes actionable insights for improving offshore construction practices and informing regulatory safety standards.Keywords: Steel Scaffold, Dynamic Buckling, Periodic Wind Load, Offshore Platform1. INTRODUCTION Steel scaffolds play a vital role as temporary structural systems across offshore oil and gas platforms, supporting a wide range of activities such as construction, inspection, repair, and maintenance. Their modular design, high adaptability, and straightforward assembly make them especially suited for the challenging conditions of marine environments, where flexibility and rapid deployment are critical for operational efficiency and safety 1, 2. However, when deployed in offshore environments, steel scaffolds are routinely subjected to complex dynamic loads such as periodic wind pressures, wave-induced vibrations, and fluctuating environmental forces. These cyclic excitations can significantly affect structural stability, making scaffolds vulnerable to dynamic instabilities particularly buckling under harmonic excitation, which poses serious risks to safety and operational continuity 3, 4. Offshore platforms are frequently subjected to sustained sinusoidal wind loading, arising from steady marine breezes and periodic gusts that differ significantly from the wind patterns encountered onshore. Unlike conventional civil structures, scaffolds installed in offshore environments often face low-frequency oscillatory forces. These loads can closely match the natural frequencies of the scaffold systems, potentially leading to resonance a condition where structural responses are significantly amplified, increasing the risk of instability and failure 5, 6. These dynamic conditions are further intensified by the inherently slender geometry and pin-jointed configurations of scaffolding elements, which often lack the mass and lateral stiffness required to resist deformations under resonant excitation. The lightweight and flexible nature of scaffold structures, while advantageous for assembly and adaptability, also makes them more vulnerable to instability when exposed to sustained dynamic loads. In extreme cases, the failure or collapse of scaffolding systems can result in serious safety hazards, costly operational disruptions, and even loss of life, particularly in high-risk offshore environments 7, 8.Traditional scaffold design approaches often rely on quasi-static load assumptions and generalized empirical safety factors. While these methods provide a baseline for structural integrity, they fall short in capturing the complex, time-dependent, and frequency-sensitive behavior exhibited by scaffolds under dynamic loading conditions. As a result, critical phenomena such as resonance, fatigue, and transient instability may be overlooked, potentially compromising safety and performance in offshore environments where dynamic forces are predominant 9, 10. Moreover, existing codes of practice such as BS EN 12811 and OSHA regulations primarily emphasize load-bearing capacities, geometric configurations, and safety under static or quasi-static conditions. These standards often lack detailed provisions for addressing time-varying dynamic excitations or the modal behavior of scaffold structures under real-world operating conditions. Consequently, a significant gap remains in the understanding and analysis of dynamic buckling phenomena, particularly for temporary scaffold systems exposed to vibration-rich offshore environments where resonance and fatigue can severely compromise structural integrity 11, 12.Several foundational studies have explored dynamic buckling in structural elements. Budiansky and Roth introduced analytical models for columns under time-varying loads 13, which were later extended by Simitses and Hodges to include damping and geometric nonlinearities 14. While these models are well-established in aerospace and civil engineering applications, their direct use in modular steel scaffolds is limited due to the scaffoldsunique characteristics such as discrete connections, low damping, and flexible joints which complicate dynamic buckling analysis. Steel scaffolds used on offshore platforms often face fluctuating wind forces caused by the unpredictable and harsh oceanic weather. However, conventional design practices tend to emphasize static or quasi-static loading conditions, overlooking the effects of cyclic and resonant forces generated by harmonic wind loads 5, 16. This oversight can result in inaccurate estimations of failure thresholds, potentially leading to unexpected structural failures. When resonance or amplified vibrations occur, the risk of scaffold collapse significantly increases posing serious safety concerns for personnel involved in offshore maintenance and repair activities.Although wind-induced failures are a known concern in offshore environments, there is still a noticeable lack of research focused on the time-domain dynamic buckling behavior of scaffold structures under harmonic loading especially when considering realistic offshore wind patterns. This study aims to bridge that gap by developing a MATLAB-based numerical framework to simulate the real-time dynamic response of scaffolds exposed to periodic wind forces. The analysis specifically focuses on identifying conditions that increase the risk of buckling, providing insights that can improve the safety and reliability of scaffolding systems used in offshore operations.
Copyright
Copyright © 2025 Raphael Okosiemiema1. This is an open access article distributed under the Creative Commons Attribution License.
