摩擦耗能型翼缘削弱式钢梁连接的承载性能

Mechanical behavior on friction energy dissipation reduced beam section connection of steel beams

提出一种摩擦耗能型翼缘削弱式(RBS)钢梁高强螺栓的连接形式,可实现塑性铰外移的效果。由设置在钢梁腹板中部的横隔板和腹板共同组成H型凸起抵抗剪力,不仅节省了钢梁腹板位置的大量抗剪螺栓群,在钢梁吊装时还可作为搭接平台,实现钢梁的快速安装。在H型钢梁摩擦型高强螺栓连接试验验证的基础上,利用ABAQUS有限元软件建立了摩擦型RBS钢梁连接的数值模型。与传统钢梁连接形式相比,摩擦型RBS钢梁连接的受力过程可分为:弹性阶段、滑移阶段、强化阶段和塑性阶段,在摩擦滑移阶段和全截面屈服阶段可形成2级耗能机制。改变翼缘螺栓预紧力、盖板厚度、翼缘厚度以及钢材强度等参数,对摩擦型RBS钢梁连接的工作机理和承载性能变化规律进行分析。摩擦型RBS钢梁连接具有良好的承载力和塑性转动能力,可得到与骨式翼缘RBS钢梁相似的塑性铰外移的效果,且转角延性系数由1.7提高到12。摩擦型RBS钢梁连接滑移阶段的抗弯承载力主要与翼缘螺栓群的极限摩阻力相关,而塑性阶段极限抗弯承载力则与螺栓强度、栓杆直径以及钢梁塑性极限弯矩等因素相关。

A new Reduced Beam Section(RBS)connection of steel beams used high-strength friction bolts was investigated in this paper.A H-shaped shear key was designed as a horizontal plate at the midline of the web plate and the steel beam under its midline.Lots of the resisting shear friction bolt groups at the web of the beam section were saved,and the H-shaped shear key could also be used as the landing platform for the purpose of fast installation when the steel beam was lifted in the air.Based on the experimental verification of the high-strength friction bolted connection of the H-shaped steel beams,the Finite Element Analysis models were built using ABAQUS software.Compared with the traditional steel beam connections,the bearing capacity process of the high-strength friction bolted RBS connection could be divided into four parts:elastic stage,sliding stage,strengthen stage and plastic stage,and two energy dissipation mechanisms were formed during the frictional sliding and plastic yield stages,respectively.The mechanical performance of the high-strength friction bolted RBS connection was analyzed with different parameters such as bolt pretension force,thickness of the connection plate and strength of the steel materials etc.The working mechanism and bearing capacity of the high-strength friction bolted RBS connection were analyzed in this paper.The bearing capacity and ductility of the high-strength friction bolted RBS connection was good,and the relocation of plastic hinge similar to the flange Reduced Beam Section steel beam was also found,the angular ductility factor increased from 1.7 to 12.The moment inter force at the beginning of frictional sliding was determined by the friction resistance capacity of the highstrength friction bolt groups at the steel beam flange,however,the bearing capacity during the plastic stage was relevant to the bolt strength,bolt diameter and the ultimate plastic moment of the steel beam.