Light Steel End Plate Connections Joints

With the development of economy, and the increase of output and quality of steel in our country, the application of portal frame building has becoming more and more prevalent. At the same time there hasn't existed mature method on rotation of the end-plate connection, the standards and specification related can only provide classical design method, most of the assumption do not reflect the actual stress state. Probably the designers think rarely about the rotation of connections. It is worthy to research the rotation of the end-plate rigid node in beam & column which decrease the restriction that beam give to column ,and also add the column's account length and the beam's flexibility. All of above summon us to do more discussion with the distortion capability in connection and the effect which gives structure.According to the literature, the prominent excellence of the extended end-plate connection with stiffeners lies in its good load-bearing performance, steady energy performance and handily to construct, so it is valuable to be generalization.In this paper, it selects classical end-plate thickness design methodology, and then discusses the affection of its semi-rigidity and its infection to portal frame's force and deformation which based on energy approach. It draw a conclusion that generally the connections' semi-rigidity has biggish affect to portal frame's stress and deformation, when the portal frame's rigidity is large ,its connection can be designed as rigid connection. But when small, it can reduce the frames unsafely. So gives a suggestion that it should enlarge connections rigidity in design.In succession five connections' modes were built through finite element process, considering the material's nonlinear, and contact elements was built with initial stress was applied to the high strength bolt. Then the connections' stress and deformation's weak place is caught out, and the connections' web and column's end-plate's lower eyelid's Mises stress excess other position's out and away. The web's rotation of connection does occupy a 60-80% to the whole rotations. But the whole rotation can be minified to its original's 30-50% if a web's stiffness is given. And the stress distribution can also be improved. Further more, it can be find that both the upper and the lower half of end-plate have high level stress, so it is necessary to check calculation on both the upper and the lower half.Then at the fourth component, hysteretic behavior of five different modes was analyzed. It discovered that good linear rigidity can be achieved by conformation, which preferred good predictability to the design of resistance to deformation for regular service. Besides, this kind of connections has good ductility under larger load, which illustrated that it also have good power-wasting nature.In the fifth chapter, the conclusion about the end-plate connection node was used in practical construction project and compared with the stress and deformation, which provides reference about using steel economically.At last, it gives valuable conclusion and suggestion to construction design, also make a foundation for further study of this kind connections' performance.