鋼柱與鋼梁腹板開孔位處塑性區梁柱接頭之耐震行為

Abstract

鋼梁腹板開孔位處塑性區域將影響鋼梁的塑性變形能力與鋼梁的撓曲與剪力強度。本研究針對鋼梁接H型鋼柱於鋼梁塑性區開圓形孔之梁柱子結構以實尺寸實驗方式探討其耐震行為。五組試體包含一組未補強之梁柱接頭試體，與四組以剪力板或垂直加勁板補強梁柱接頭處之試體。試驗結果顯示五組試體在剛進入非彈性行為時，在鋼梁腹板開孔處皆可達彎矩與剪力互制之強度，且於極限狀態試體皆能達鋼梁之標稱塑性彎矩強度。試體於鋼梁塑性區腹板開孔，其塑性變形能力則有賴梁柱接頭之補強，未補強之試體無法發展出足夠之韌性，惟以剪力板或垂直加勁板補強之試體則可發展出令人滿意的韌性行為。

Steel beams with web openings in plastic zone will affect the plastic deformation capacity and bending and shear strength of the steel beams. This research was conducted to experimentally investigate the seismic behavior of beam-to-column subassemblages, consisting of H-shaped steel columns and steel beams with circular web openings in the plastic zone. Five full-scale specimens were tested in this study. One is unreinforced beam-to-column connection, and the other four specimens are reinforced with either shear tab or vertical stiffener at beam-to-column connection. Test results indicated that all five specimens can develop strengths based on the interaction between bending and shear when the specimens just underwent the inelastic behavior, and all specimens can achieve the nominal plastic flexural strength of the steel beams at ultimate states. The plastic deformation capacity of the specimens having web openings in plastic zone of the steel beam depends on the reinforcement at beam-to-column connection. The unreinforced specimen could not develop enough ductility, while the specimens reinforced with shear tab or vertical stiffener can achieve satisfactory ductile behavior.