Research On Buckling Stability Of Thin-walled Lipped H-section Members By One-way Bending

Cold bending thin-wall steel elements have been rapid development and application for their good performance in recent years at home and abroad. But stability problem is outstanding and it needs to be solved in the design work. Lipped H-section is a new type of cross section which was put forward some years ago. The main problem is to improve the local buckling stability of the flange and to enhance the lateral stiffness of the components. Due to the insufficient data of research on lipped H-section, the performance of the lipped H-section is not clear. This article focuses on buckling stability of one-way bending artifacts.The way of cold bending thin-wall steel component stability in our current code is the effective width method, and that is direct strength method abroad.In this paper,21members had been designed according to the existing specifications and the related literatures before, and had been carried on the finite strip analysis. To change five parameters, namely, the lip’s width ratio、width-height ratio、width-thickness of web、the width-thickness of flange and eccentricity, and analysis the relationship between them and the stability, then some design suggestions are put forward. The influence law of various parameters on the bearing capacity of components by the results is that under the same eccentricity, width-thickness of web and the width-thickness of flange significantly influence on the stability of the member, width-height ratio affects it some extent, and the lip’s width ratio which is between0.2to0.4can afford strong support to the member; and if the section is confirmed, big eccentricity weakens the stability obviously and small one weakens little. Some suggestions are put forward. The first is that control the lip’s width ratio between0.2to0.4; The second is that width-thickness of web and the width-thickness of flange should be strictly limited and conform to the relative codes; The third is that when the eccentricity is big,the buckling stability should be discounted.