考虑撬力的高强螺栓T形受拉连接设计现状

通过分析T形高强螺栓受拉连接的破坏机理,讨论了撬力作用产生的原因及影响因素;着重提出了高强螺栓外伸端板连接存在的3种可能的承载能力极限状态;当端板的刚度较小时,其弯曲变形将造成明显的撬力,从而增大了螺栓受力,使整个连接破坏。通过比较国内外钢结构设计中对T形及外伸端板连接的相关设计方法,指出现行的《钢结构设计规范》(GB50017-2003)以及《门式刚架轻型房屋钢结构技术规程》(CECS102∶2002)中关于端板厚度计算公式中均没有考虑实际撬力的大小,过于保守。

RESENT SITUATION OF DESIGN ON HIGN STRENGTH BOLT T-SHAPED TENSILE CONNECTION CONSIDERING PRYING ACTION

It is analyzed the collapse mechanism for the tensile connection of T-shaped high strength bolt,and discussed the reason and the influence of prying action. It is referred that there may be three carrying capacity limit states of extended end-plate moment connections. When the stiffness of the end-plate is undersized,the deformation of bending will bring obvious prying force. The prying force can result in the increment of bolt force,by which the connection failed. By comparing the difference on prying force calculation with the design codes of other countries,it is reasonable that prying force should be calculated when designing bolt and connection members,and corresponding measures should be done when the prying action need to be eliminated. In “Code for Design of Steel Structure” (GB 50017-2003),there is no formula for calculation of prying force. As well as in “Technical Specification for Steel Structure of Light-Weight Buildings with Gabled Frames”(CECS 102∶2002),it doesn't calculate the actual prying force in formula for thickness of endplate,and it is also conservative.