The Research On The Compression Stability Performance Of Cold-formed Thin-wall Lipped Channel Column With Stiffer Plates

Based on the existing achievements around the world on the distortional buckling, We know that when distortional buckling happens, the flange and the lip will rotate about the flange-web junction. According this deforming feature, we decide to increase connecting stiffer-plates between the two lips to improve the load capacity. In this paper, the finite element method software of ANSYS is used.Nonlinear finite element analysis involving geometric large deformation and materials nonlinear is used to simulate test columns under monotonic load in this paper. Members are modeled as shell elements. The equation resolution method is selected as arc-length method. The finite element analysis results are close to that of the tests, so the finite element analysis method is correct.The parameters affecting the strength of cold-formed thin-walled lipped channel column with stiffer plates are researched through a series of nonlinear finite element analysis. The influences of stiffer plates spacing and eccentric distance on the crippling capacity is ascertained. According to analysis, we have found that when the stiffer plates spacing is one third of half-wave length of distortional buckling , there will be 9%～15% improvement for central-load column, and the improvement is most effective for eccentric-load column.According to the results of nonlinear finite element analysis, A predicting expression is proposed to determine the ultimate bearing capacity of cold-formed thin-walled lipped channel column with stiffer plates. The comparison of calculating strength to nonlinear finite element result shows that the proposed expression is reasonable. The method will be some of value in the engineering practice.