鋼柱基底含形狀記憶合金裝置之自復位與消能

Abstract

本研究探討鋼柱基底含形狀記憶合金裝置之消能與自復位行為，利用形狀記憶合金之超彈性以鉸接方式將鋼柱與基礎接合，取代傳統的銲接或螺栓接合，使結構擁有承受地震後自復位與無殘餘變形之能力。研究參數包含柱頂垂直載重大小與形狀記憶合金裝置，探討其於子結構之自復位以及消能行為之影響。研究方法先採理論推導，建立子結構遲滯迴圈之行為模式；進而規劃試體進行試驗，以驗證其行為。形狀記憶合金材料試驗顯示其超彈性深受熱處理影響。實驗結果之遲滯迴圈顯示藉由柱頂之垂直載重與形狀記憶合金裝置之超彈性，使得子結構具有良好之自復位與消能能力。柱頂垂直載重越大子結構之解壓彎矩越大，且間隙開啟後旋轉勁度下降也越大。理論分析模型可準確預測鋼柱基底含形狀記憶合金裝置之行為。本研究證實採用形狀記憶合金裝置於鋼柱基底，鋼柱於受反覆側向載重後可達自復位與消能之效果。

This study aims to investigate behaviors of the self-centering and energy dissipation of steel column base connections with shape memory alloy (SMA) devices. Instead of using traditional welded or bolted means, the pinned connections between the column and foundation used superelastic austenite SMAs to achieve the self-centering and without residual deformation of the structures. To explore the effects on the self-centering and energy dissipation of the subassemblage, the parameters studied included the gravity load at the column tip and the SMAs. The hysteretic behavior of the subassemblage was established analytically, and the test specimens were further designed to proceed the test and to validate the behavior. The material test of the SMAs demonstrated that the heat treatment significantly influenced the super elasticity. The hysteresis loops of the test results showed that the subassemblage was capable of the self-centering and energy dissipation attributed to the gravity load at the column tip and the use of the SMAs. The increase of the gravity load at the column tip resulted in the increase of the decompression moment of the subassemblage and the decrease of the rotational stiffness after gap opened. Furthermore, the analytical models predicted well the test results. This study had verified that the use of the SMA devices at the column base could achieve the results of the self-centering and energy dissipation while the column was subjected to lateral cyclic loads.