Abstract

Since the friction dampers possess constant friction forces, they cannot play a significant role in mitigating the strong earthquakes' demands. The application of the variable-force friction dampers is one way of circumventing this problem. In this paper, the design parameters of a specific force-variable friction damper namely Arc-Surfaced Friction Dampers (ASFD) have been investigated and their effect on the efficiency of their performance has been assessed. To this end, a 4-story structure designed according to Iranian Building Code Standard-2800 equipped with an ordinary frictional damper (LSB) and an ASFD has been excited by an ensemble of near- and far-field ground motions. To determine the optimal ASFD parameters, which in here reflected as the initial sliding force and the radius of curvature of the ASFD, the response of the structure due to 44 FEMA-p695 ground motions scaled to the elastic design spectra corresponding to 10% of exceedance in 50 years are estimated. The nonlinear dynamic analysis has provided a basis to define the optimal parameters concerning the life-safety and collapse-prevention performance. The results showed that implementing the ASFD as a control device has significantly reduced the median spectral acceleration corresponding to the onset of collapse compared to the uncontrolled structures.

摘要

由于摩擦阻尼器具有恒定的摩擦力，因此它们不能在减轻强地震的需求方面发挥重要作用。变力摩擦阻尼器的应用是规避这个问题的一种方法。在本文中，研究了特定力可变摩擦阻尼器即弧面摩擦阻尼器 (ASFD) 的设计参数，并评估了它们对其性能效率的影响。为此，根据伊朗建筑规范 Standard-2800 设计的 4 层结构，配备普通摩擦阻尼器 (LSB) 和 ASFD，已被近场和远场地面运动的集合激发。为了确定最优的 ASFD 参数，这里反映为 ASFD 的初始滑动力和曲率半径，估计由于 44 次 FEMA-p695 地面运动引起的结构响应，按比例缩放到对应于 50 年超过 10% 的弹性设计谱。非线性动力学分析为确定有关生命安全和防倒塌性能的最佳参数提供了依据。结果表明，与不受控制的结构相比，实施 ASFD 作为控制装置显着降低了与坍塌开始相对应的中值光谱加速度。