PSI - Issue 78

Alvaro Lopez et al. / Procedia Structural Integrity 78 (2026) 807–814

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5.5. Comparison of responses

The hysteretic response curves show that the wall tested under the Angol displacement history showed higher stiffness and less strength degradation compared to the wall tested under standard loading protocol. However, the chosen scale factor for the long-duration displacement history was not enough to induce complete failure on the specimen, but it did induce more damage at the same ductility levels. Comparison of these two walls against W2-SD tested under the Brinza displacement history cannot be made due to the premature failure of the test setup.

(b)

(a)

Fig. 5. (a) Damage and (b) hysteretic response of wall W3-LD

Fig. 6. Hysteretic response comparison

6. Conclusions In this study, three ½, flexure-dominated RC shear walls were tested under long-duration, spectrally equivalent short-duration, and standard cyclic displacement histories to assess the influence of ground motion duration on seismic performance. The key conclusions are: • Cumulative Damage Amplification: Long-duration displacement histories markedly accelerated crack propagation, concrete cover spalling, and reinforcement buckling at lower ductility demands (μ≈4), indicating that conventional cyclic protocols substantially underpredict cumulative inelastic damage under prolonged subduction-type shaking. • Reduction in Displacement Capacity: The specimen subjected to long-duration motions exhibited a peak drift capacity approximately 15 % lower than the control wall tested with the standard protocol, confirming that low-cycle fatigue effects degrade ultimate deformation capacity in RC shear walls.