A Study on Collapse Mode and Plastic Deformation Capacity of H-Shaped Steel Beams Under Shear Bending

Abstract

In a recent study ， it was clear that the beam with large web slenderness has enough plastic deformation capacity for seismic design ． But the large deformation behavior and the collapse mechanism of these beams have not been cleared 、 In this study ， the collapse mode and that deciding the maximum load are investigated by exper 至 ment study and numerical analysjs ， As a results ， it is clear that the ratlo of the shear strength to bending strength of the beam is very important factor for the plastic deformation behavior ． And the plastic deformation capacity of the beam is estimated by using the ratio ．

Post Local Buckling Behavior and Ultimate Capacity of H–section Beam

“…That is to say that the type of buckling mode is mainly dependent on (d/t w )/(b/t f ). Fig.12. shows the relationship between the depth and width-thickness ratio of H-section beams which have been tested in this and other studies 6,10,11) . In addition, the results dealt with by numerical analysis (FEM) are included by diamond plots in Fig.12.…”

“…α : ratio of τ crw to σ crw expressed by 13,14,15) Cyclic test Monotonic test 6) Monotonic test 10) Monotonic test 11) …”

“…The plots in Fig.13. designate the relationship between WF and µ obtained from cyclic test, monotonic test 6,10,11) and a number of FEM analysis under monotonic loading. The aspect ratio of webs are about 4<λ w =l/d<12, and the ratio of the plate sectional area are about 0.5<A f /A w <2.…”

“…Recently, some experimental studies 6), 10), 11) have shown that sometimes the thin-walled H-section beam might have elastic stability as well, even if the depth-thickness ratio of the web is larger than the limit value of the current standard. However, so far, no standardized method has ever been able to estimate the maximum strength and plastic deformation capacity of such beam, because the calculation of local buckling strength was obtained on the assumption that the web or flange is regarded as a single plate with simplified boundary condition, and the coupled instability of the web and flanges was not taken into consideration.…”

“…Therefore the widththickness ratio and depth-thickness ratio of the plate are assumed to be a major parameter to determine the ultimate capacity of a thin-walled steel beam or column. Up to now many experimental and analytical studies [3][4][5][6][7][8][9][10][11][12] on the H-section beam have been reported. These studies mainly aimed at revealing the correlation between the width or depth-thickness ratio and ultimate capacity subjected to an H-section beam under monotonic loading.…”