| At present, H steel plays a decisive role in China. And in the steel structure building, H steel is mainly used in the beam, column and crane girder of portal frame. However, due to the ratio of height to thickness of plain web H steel restricted, stiffening rib and other measures are needed to improve its stability, which greatly increases the weight of structure and the cost of the project. Therefore, based on the existent problems of the plain web H steel, the appearance of the H-beams with corrugated webs make a series of problems solved. H-beams with corrugated webs could be obtained better shear buckling strength and stiffness with small thickness of corrugated steel, which does not require the assistance of the stiffening rib. It greatly reduces the material consumption and reflects the significant economic benefits. On the basis of the superiority of the corrugated steel web, scholars at home and abroad have carried out a series of research on the structure in recent years, and received valuable conclusions.This paper mainly uses H-beams with sine wave corrugated web as the research object to study on the shear buckling behavior by applying ABAQUS finite element software. Then the comparisons of the shear buckling behavior of triangular and rectangular corrugated web are in progress under the same conditions. Meanwhile, in order to reduce material usage, the geometric parameters of sine wave corrugated web are optimized. The main research contents are as follows:(1) The buckling theory of corrugated web are elaborated in detail in this paper, including the flexural buckling theory, torsional buckling theory and shear buckling theory, which focuses on the introduction of the three buckling modes of shear buckling. In the process of expounding the shear buckling theory of the corrugated steel webs, according to the research object and on the basis of the calculation formula for the buckling strength of the trapezoidal corrugated form, the calculation formula of the global and local buckling strength and the constraint condition of the subsequent optimization study applying for the sine wave corrugated webs are derived;(2) ABAQUS finite element software is used to study on the elastic buckling analysis of the H-beams with sine wave corrugated webs under the simply supported condition, which focuses on the research of the influence of buckling behavior of the span of H-beams and geometric parameters of sine wave corrugated webs, including web thickness, web weight, wavelength and amplitude. According to this, a large number of the critical buckling load are obtained, and the change relation curves can be drawn by using Origin, which can sum up the change regulation and conclusion of the critical buckling load along with each dimension parameter changing. At the same time, for the sake of providing a theoretical basis for the comprehensive development of a variety of corrugated forms in the future, the similarities and differences of shear buckling behavior of the triangular corrugated, rectangular corrugated and sine wave corrugated are compared and analyzed;(3) The basic function finincon in the MATLAB optimization toolbox is used to optimize and process the geometric parameters of the sine wave corrugated webs, which focuses on the study of constrained nonlinear problem and depiction of how to compile the M file of constraint function, objective function and other constraints with MATLAB. Through the optimization and processing by MATLAB, the optimum solution and the optimal value of the objective function can be obtained. Combined with the influence law of geometric parameters to the critical buckling load, the geometric parameters or ranges can be finally achieved which meet the favorable buckling behavior and minimum steel. |
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