擴翼式鋼骨托梁抗彎接頭之耐震行為

Abstract

本研究藉由有限元素分析與實尺寸梁柱接頭試驗，探討擴翼式梁柱接頭於鋼骨托梁抗彎構架之耐震行為。托梁系統即將ㄧ短梁先行於工廠銲接於柱面，至工地再以螺栓或銲接與續接梁接合。本研究對托梁韌性抗彎接頭之接合細節改良有：無扇形銲接開孔與擴翼托梁型式。由非線性有限元素分析顯示，此改善接頭細節可有效的降低於梁翼全滲透銲道兩側之應力集中與塑性應變需求。進行三組實尺寸梁柱接頭反覆載重試驗。試驗結果顯示，所有試體皆具優良之韌性行為且無發生脆性破壞，塑鉸機制亦遠離梁柱交接面產生。因此，採擴翼型式與無扇形銲接開孔之接合細節可有效降低梁柱接面發生脆性破壞之可能性。本研究最後提供初步之擴翼式梁柱接頭之設計流程以供參考。

This research aims to investigate the seismic behavior of steel column-tree moment connections with widened flange through nonlinear finite element analysis and full-scale test. The column-tree system is to connect the column-trees and link beams in the field while the column-trees are fabricated in the shop by welding stub beams to the column. No weld access hole detail and widened flange of the stub beam are two important improvements in the connection details of the ductile moment connections. Numerical study demonstrated that the improved connection details significantly reduce the stress concentration and plastic strain demands at the beam complete joint penetration weld. Three full-scale specimens were carried out to verify cyclic behavior of the column-tree moment connections. The test results showed that all specimens successfully develop ductile behavior without brittle fracture, and plastic hinge formed in the beam away from beam-to-column interface. Consequently, the improved connection details, widened flange and no weld access hole detail, efficiently decrease the potential of brittle fracture. Preliminary procedure for designing widened flange is proposed.