本研究針對方形冷沖壓成型鋼管柱（Box Column by Cold Press Forming， BCP）與 H 型鋼梁之外柱梁柱接合進行耐震性能研究。BCP 方形鋼管柱配合貫穿式橫隔板，可使梁翼板力量經由橫隔板傳遞至柱構件，降低柱板直接承受面外拉力；然而，梁翼板全滲透銲道、銲道端部、起訖弧方式與銲接扇形孔等細部，仍可能影響梁端局部應力集中、裂縫起始位置及塑鉸發展行為。因此，本研究規劃五組實尺寸外柱梁柱接合試體，包括無扇形孔試體 WUF-N、雙圓弧扇形孔試體 WUF-B/DA35、倒四分之一圓扇形孔試體 IQ35、增設根部的倒四分之一圓扇形孔試體 WUF-B/IQ35-h，以及偏心單側擴翼試體 EBS-BS/DA25。各試體梁均採 BH 750×300×15×22 之 SN490B 組合 H 型鋼梁，並依 AISC 341-22 漸增反覆載重歷時進行試驗，以層間位移角作為主要控制與性能判定指標。試驗結果顯示， WUF-N 與 WUF-B/IQ35-h 可完成至少一個 4% 層間位移角之完整反覆載重迴圈；其餘試體則於完成 4%完整迴圈前發生翼板或銲道附近破壞。EBS-BS/DA25未擴翼側上翼板於 3% 負向第一圈發展為明顯開裂，顯示單側擴翼所造成之不對稱受力與偏心效應不可忽略。破壞後斷面觀察亦發現，部分試體雖於試驗前通過非破壞檢測，銲道端部仍可見局部瑕疵，顯示銲接程序、端部處理對試驗結果具有高度相關。在本研究之試體與施工條件範圍內，改變扇形孔形狀未呈現明顯耐震性能改善趨勢。綜合本研究與相關 BCP 梁柱接合試驗結果，若欲進一步提升梁柱接合之變形能力，後續設計宜以使塑鉸遠離柱面與梁翼板全滲透銲接區為主要方向，並同時控制銲接細部與施工品質。;This study investigates the seismic performance of exterior beam-to-column connections consisting of square steel tube columns fabricated by cold press forming (BCP columns) and H-shaped steel beams. Through-diaphragms are adopted to transfer beam-flange forces into the column; however， weld access holes and welding details may significantly affect local stress concentration， crack initiation， and plastic-hinge development. Five full-scale specimens were tested under reversed cyclic loading， including a no-weld-access-hole specimen (WUF-N)， a double-arc specimen (WUF-B/DA35)， two inverted quarter-circle specimens (WUF-B/IQ35) and (WUF-B/IQ35-h)， and a single-sided widened-flange specimen (EBS-BS/DA25). All beams were fabricated from SN490B steel with a BH 750 × 300 × 15 × 22 section. Seismic performance was evaluated based on hysteretic response， strength， deformation capacity， strain response， crack development， and failure mode. The results showed that noticeable nonlinear behavior generally began at approximately 0.75% story drift. WUF-N and WUF-B/ IQ35-h completed at least one full cycle at 4% story drift， whereas WUF-B/DA35 and WUF-B/IQ35 experienced significant flange- or weld-related damage before completing the 4% cycle. No consistent improvement in seismic performance was observed solely by changing the weld access hole shape. Instead， welding quality， weld-end treatment， and local weld discontinuities had a more pronounced influence on crack initiation and failure. For EBS-BS/DA25， the single-sided widened flange increased strength but caused asymmetric force transfer and stress concentration on the non-widened side， where cracking initiated at 0.75% story drift. The results suggest that future connection design should emphasize welding quality control and shifting the plastic hinge away from the column face and beam-flange CJP weld region.
