International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 12 Issue: 05 | May 2025
p-ISSN: 2395-0072
www.irjet.net
TO STUDY LATERAL LOADING PERFORMANCE OF STEEL FRAME WITH NOVEL CROOKED BRACING SYSTEM ASNA P A 1, JINU V R2 1Post Graduate Student, Dept. of Civil Engineering, KMEA Engineering College, Edathala Ernakulam, Kerala 2Assistant Professor, Dept. of Civil Engineering, KMEA Engineering College, Edathala Ernakulam, Kerala
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Abstract - This study investigated the Lateral loading
welded beam to column connection and classifies the damage prior knowledge and challenging addressing it (e.g. [2-4]).
performance of various curved braces, specifically the single curved V, single inverted curved V, D-type, double inverted curved X, and double curved X-type braces. A comprehensive nonlinear analysis, along with a dimensional parametric study, was conducted to evaluate the behavior of these curved braces under different conditions. A numerical finite element analysis was performed using ANSYS Workbench FE software. A comparative study between o grid and novel crooked bracings and effective model is identified and time history analysis with PGA data is performed. Conclusive statements on the overall performance comparison, highlighting the single and double curved braces we developed have greater ductility, load carrying capacity, energy absorption than o-grid and other conventional bracings. The result shows double inverted curved X-brace also demonstrated excellent load capacity and ductility, with a maximum load capacity of 139.65 kN and a ductility factor of 40.96, which 9.6 times than O-Grid bracing systems. By performing time history analysis, the result shows that the double inverted curved brace the top story displacement decreases by 16.69% & the acceleration drops by 28.39% compared to O-Grid and time period is reduces. So, the double inverted x-brace performs more effectively than O-Grid systems, showing a notable reduction in both acceleration and displacement.
In high-rise buildings, seismic design often prioritizes stiffness over strength to enhance overall performance during earthquakes. Steel structures typically use momentresisting frames and braced frames to counteract lateral forces. Moment-resisting frames provide high ductility by allowing controlled yielding in connections, but they often lack the stiffness needed for tall buildings. Concentric braced frames (CBFs), on the other hand, offer substantial stiffness but have limited capacity to deform without failure. Various configurations such as diagonal, X, V, and chevron bracing enhance seismic resistance by effectively tying braces into beam-column junctions.To combine the benefits of both stiffness and ductility, Eccentric Braced Frames (EBFs), developed by Roeder and Popov, incorporate shear links that deform inelastically to dissipate seismic energy. However, repairing these shear links after a major seismic event can be complex and costly. As an alternative, the Knee Braced Frame (KBF) was introduced by Ochoa, featuring a specially designed knee element that yields under stress, thereby absorbing energy more efficiently. This concept was further improved by Balendra and colleagues, who proposed modifying chevron braced systems by using relatively weaker braces paired with stronger beams. This adjustment enhances ductility and allows for a more distributed pattern of damage across the structure.
Key Words: Novel Crooked bracing system, Innovative lateral loading system, Steel structures, Push over analysis, Time history analysis, PGA data
Following the 1995 Kobe earthquake, Buckling-Restrained Braced Frames (BRBFs) gained popularity in seismic-prone regions. These systems feature a steel core encased to prevent buckling, allowing it to yield in both tension and compression. This configuration offers reliable energy dissipation and stable hysteretic behavior. However, because the yielding core is relatively slender, BRBFs tend to be more flexible and may concentrate damage in specific stories. Moreover, they often experience significant residual deformations after seismic events due to their low post-yield stiffness. (e.g. [ 5-81]).
1.INTRODUCTION In the design of structures, it is necessary to consider lateral loads and Lateral Load Resisting Systems (LLRS). LLRS are indispensable in the design of buildings located in the seismic prone areas. In order to prevent structural collapse, it is important that during severe earthquakes, lateral load resisting systems should have appropriate ductility, stability and resistance. The 1994 Northridge earthquake exposed unexpected brittle fracture in steel moment resisting frame (MRF) connections, challenging long-held assumptions about their seismic reliability (e.g. [1-2]). The paper reviews the damage sustained by steel buildings during 1995 Hyogo ken -Nanbu earthquake focusing on seismic design., building characteristics, and damage patterns.it highlights failures in
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1.1 O-grid Bracing System Many ways studied to improve steel bracing systems, and one effective idea is using circular-shaped elements. Murty [82] tested a circular part in a toggle bracing system and
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