Research on mechanism of torsional effect and limits of critical parameters of asymmetric base-isolated structures
ZHANG Jiayu1，QI Ai1,2，YANG Mianyue1
1.College of Civil Engineering, Fuzhou University, Fuzhou 350116, China;
2.National and Local United Research Center for Seismic and Disaster Informatization of Civil Engineering， Fuzhou University, Fuzhou 350116, China
Abstract：Compared with traditional seismic structures, it is easier to control the critical parameters in a reasonable range by adjusting the layout of isolators, so as to reduce the adverse impact caused by superstructure eccentricities.Therefore, from the perspective of the torsional mechanism of asymmetric base-isolated structures, the influence law and degree of the torsional to lateral frequency ratio of base-isolated structures and the eccentricity in the isolation system on the torsional effect in different value ranges were analyzed.Results show that, the smaller the torsional to lateral frequency ratio is, the more obvious the torsional response is, and the small eccentricity in the isolation system will aggravate the torsional response.Torsional response is weakened when the torsional to lateral frequency ratio is greater than 1.2, and the eccentricity in the isolation system is close to a positive correlation with torsional response.Then, the explicit limit displacement ratio of the furthest isolator from the center of mass with or without eccentricity was derived under the condition that the displacement of isolator did not exceed the allowable value.The results of analysis indicate that there is a maximum isolation period to make the limit value obtain a minimum value.According to this, the limit value of the eccentricity under different torsional to lateral frequency ratios can be obtained, and the torsional response can be controlled within the limit range effectively, which provides effective references for designers in torsional design of asymmetric base-isolated structures.
张佳雨1，祁皑1,2，杨绵越1. 偏心隔震结构扭转效应机理分析及关键参数限值研究[J]. 振动与冲击, 2023, 42(24): 32-41.
ZHANG Jiayu1，QI Ai1,2，YANG Mianyue1. Research on mechanism of torsional effect and limits of critical parameters of asymmetric base-isolated structures. JOURNAL OF VIBRATION AND SHOCK, 2023, 42(24): 32-41.
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