鋼筋混凝土柱與鋼梁接頭耐震行為

Abstract

本研究計劃乃屬於一整合型複合構造行為研究計劃之子計劃，研究內容旨在探討鋼筋混凝土柱接鋼梁之梁柱接頭子結構在模擬地震力作用下之非線性行為與力量傳遞機制。本研究共規劃設計三組試體，根據文獻建議採用之接合細節有加勁鐵筐、橫向鋼梁等，並搭配不同型式之交會區剪力箍筋。試驗結果顯示試體首先於交會區混凝土產生剪力裂縫，繼而鋼梁翼板與腹板降伏而於梁端部形成塑性鉸，而後鋼梁翼板與腹板產生局部挫屈造成強度衰減，最後導致鋼梁翼板撕裂造成最終破壞。梁柱接頭設置不同型式之箍筋，實驗結果顯示三組試體之交會區變形僅有些許非線性行為，故於交會區所設置之不同箍筋型式，皆提供交會區良好之圍束及剪力強度。梁柱接頭正交橫梁設置之有無，對交會區剪力裂縫型式有差異，惟對整體行為並無影響。遲滯迴圈顯示試體擁有相當的強度與韌性消能能力，耐震性能良好，更可知約90％之變形乃集中於鋼梁，交會區剪力變形有極微非線性之行為，柱則保持在彈性範圍內；消能機制主要由鋼梁非線性行為所提供，符合耐震設計強柱弱梁之設計理念。

This study is a sub-subject of an integrated composite structural behavior research plan. The goals of this study are to investigate the non-linear behavior and force transferred mechanism of the subassemblages of beam-to-column connection between reinforced concrete column and steel beam. Three specimens were designed to have connection details considering steel band, transverse beam, and configuration of lateral tie in the panel zone. Experimental results show that shear creaking first occurred on the concrete surface in the panel zone. Steel beam flange and web then yielded and plastic hinge formed at the beam end close to column. Local buckling took place at the beam flange and wed was observed, which resulted in decreasing of the connection strength. The mode of failure was the tearing of beam flange. Test results indicated that slightly non-linear behavior was occurred in the panel zone for all specimens in spite of different configurations of lateral ties used in the joint. The presence or not of the transverse beam led to different shear cracking pattern in the joint, but resulted in the same global behavior of specimens. Hysteretic diagrams revealed that specimens have enough strength and ductility. Inelastic deformation of specimens mainly contributed from the steel beam. Columns of specimens remained elastic and it confirms to the design concept of strong column weak beam. Energy dissipation was provided mainly through the plastic hinge formation of the steel beam.