PSI - Issue 70

Ajisha T T et al. / Procedia Structural Integrity 70 (2025) 27–34

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c) d) Fig. 5 Inter storey drift ratio of all models from NLTHA method a) Kocaeli b) Landers c) Loma Preita d) Northridge

a) c) Fig.6 Plastic hinge formation at the end of ground motion a) Belt truss in mode l,2 b) Performance levels c)Belttrussinmodel 5.2.2. Inter storey drift From the results of NLTHA analysis, the maximum recorded IDR values for model 1, model 2 and model 3 are 0.0173, 0.0162, and 0.0129 respectively for Loma Prieta ground motion shown in fig. On average, model 1 has experienced larger inter storey drift followed by model 2 and model 3. Model 2 has experienced a peak average storey drift of 0.0344. It is observed that model 3 experienced a 36.6% decrease in average IDR and a 92.7% decrease in average top storey drift than other models comparatively. It is due to the position of the outrigger with belt truss at the top storey that reduces the drift of the structure. 5.2.3. Plastic hinge formation sequence The nonlinear dynamic analysis is used to find the potential failure modes and locate the weak point soft the structures in terms of plastic hinges formation under a seismic event. Different failure mechanism is observed due to plastic hinge formation of all models. In all models, the plastic hinge formation sequence is first developed in braces and then beam sand columns. It is observed that model 1 and model 2 experienced maximum hinge formation throughout the height of the structure. It is noticed that this bond outrigger tends to develop more hinges than the first outrigger. b)