Analysis Of Local Web Buckling Of Coped Steel I Beams

In order to maintain the upper flange of primary and secondary beams at the same level in the nodes, the steel beam should be cut in practice. However, this cut causes reduction of lateral stiffness. So it's easy for steel beam to occur local buckling failure.The research of local buckling occurred in coped beam is still rare. Besides the coped size and other relative parameters have a large influence on buckling load of steel beam. This paper has summarize the results about coped beams both abroad and home, and has studied something that worth to make further improvement.The main focus of this paper is as follow:Firstly, it has analyzed a coped beam which can be found in the reference by the finite element analysis software ANSYS. Considering the influences of initial imperfection, material and geometrical nonlinearity, the two sides of this beam was supplied proper restraint. So the accurate calculating result is obtained. Based on the above method, it proves that simulation of local members instead of a complete coped beam can also get an accurate result as well as the accuracy of FEM simulation method .So this paper adopts the method which analyses part of a coped beam.Secondly, through parameter variation of a steel beam, such as cope length, cope height and the ratio of ho/tf, the relative buckling load value are calculated respectively. Hence some conclusions were drawn. Particularly with increasing of cope length and cope depth, buckling load of steel beams can make a decline. However, when the cope length reaches a certain length of cope, the influences become very small.In addition, the local buckling of a cope steel beam was a buckling problem of the cope plate in essence. But the theoretical formula for the current could be difficult to use reasonably for lack of consideration such as stress concentration effect and so on. Based on the existing theoretical formula, in this paper the formula is multiplied by a single adjustment factor f s which expresses comprehensive influence on buckling stress. According to the corresponding buckling stress calculated by the change of each parameter variation of beam and relationship of each parameter, the revised formula is used to calculate the corresponding single adjustment factor f s value. As a result, the formula of the single adjustment factor under the action of three main factors makes the theoretical formula of the cope steel beam in the actual project more appropriate for application. In the end, the paper suggests a few advices on the macro administration of the pricing of CR after a study of the related national and local policies, with an aim to providing the local government with a solution to the problem.