交錨型雙核心自復位斜撐發展驗證：耐震試驗及有限元素分析

Development and Validation of a Cross-Anchored Dual-Core Self-Centering Brace: Seismic Test and Finite Element Analysis

周中哲(Chung-Che Chou) ； 鍾秉庭(Ping-Ting Chung)

《結構工程》 29卷2期 (2014/06) Pp. 81-103

https://doi.org/10.6849/SE.201406_29(2).0005

摘要

預力型自復位斜撐（SCB）是利用斜撐中的拉力構件束制斜撐中的鋼受壓構件，並在斜撐受軸拉與受軸壓下提供自復位能力，即在大變形下有回到零殘餘變形的能力。在拉力構件相同應變下，前一代雙核心自復位斜撐變形量可達單核心自復位斜撐變形量的兩倍（或是在相同斜撐變形量下，拉力構件的拉應變減少一半），有效降低拉力構件彈性應變需求，為進一步地減少拉力構件所需施拉預力數量，本研究發展交錨型雙核心自復位斜撐，改變前一代雙核心自復位斜撐之兩組拉力構件及三組鋼受壓構件的配置，減少外圍斷面尺寸，且拉力構件所需施拉預力數量僅為前一代雙核心自復位斜撐之拉力構件所需施拉預力數量的一半。本研究除了說明新發展之交錨型雙核心自復位斜撐（Cross-Anchored Dual-Core Self-Centering Brace）力學理論外，並設計及試驗一組7950mm長的交錨型雙核心自復位斜撐，拉力構件均使用D16（直徑15.24mm）高拉力鋼鉸線。在歷經3次AISC（2010）反覆載重試驗與60圈疲勞載重試驗下無破壞，顯示交錨型雙核心自復位斜撐之傳力機制與理論預測相符，而且有穩定的自復位及能量消散的能力，耐震性能符合AISC（2010）規範針對挫屈束制斜撐要求在最小層間側位移角2%前不破壞原則，斜撐更可達到層間側位移角2.5%而不破壞，最大斜撐軸力可達約1700kN。本研究並利用非線性有限元素分析軟體ABAQUS分析交錨型雙核心自復位斜撐試驗行為，有限元素分析與試驗結果及理論預測相符，進一步地驗證交錨型雙核心自復位斜撐的耐震消能行為。

關鍵字

交錨型雙核心自復位斜撐 ； 高拉力鋼鉸線 ； 試驗 ； 有限元素分析

並列摘要

The steel dual-core self-centering brace (SCB) is a novel structural member that provides both energy dissipation and re-centering properties to structures under earthquakes. The axial deformation capacity of the brace is doubled by using two inner cores and one outer box and by serial axial deformations of two sets of parallel tensioning elements. A new cross-anchored dual-core SCB is proposed to reduce half the number of tensioning elements needed for applying the initial post-tensioning work compared to the original dual-core SCB, to investigate the potential use of high-strength steel tendons as tensioning elements, and to examinethe effects of number of cycles on the brace behavior, energy dissipation, and durability of the steel tendon-anchorage system. The mechanics and cyclic behavior of the new brace are first explained; a 7950-mm long cross-anchored dual-core SCB is tested six times. The cross-anchored dual-core SCB exhibits excellent self-centering property up to a lateral drift of 2.5% with a maximum axial load of 1700 kn. No damage of steel tendons, anchors or bracing members is found after three cyclic loading tests by AISC (2010) seismic provisions and 60 low-cycle fatigue tests. Finite element analysis is conducted to furtherverify the hysteretic responses and mechanics of the proposed cross-anchored dual-core SCB in the cyclic tests.

並列關鍵字

Cross-Anchored Dual-Core Self-centering Brace (SCB) ； High-Strength Steel Tendons ； Cyclic Test ； Finite Element Analysis