A Study on Effective Use of Plastic Capacity of Steel Structural Members and Components

点击翻译按钮获取中文摘要

In this project, the following subjects were investigated theoretically and experimentally, in order to make the best use of plastic capacities of members and structural components for the design of steel structures ;1) In the existing design codes for steel structures, the strength of beam-columns under biaxial bending is verified using linear interaction formulae on cross-sectional strength and member stability corresponding to the first yielding. The redundancy from the first yielding to real ultimate strength is considerably large. So nonlinear interaction formulae for beam-columns with box or H-sec-tion are proposed. The proposed formulae are verified by the numerical and experimental investigations.2) The strength tests were carried out using the well designed H-section beam models which are appropriately combined of web's width-thickness ratio and flange's one in order to make clear the limiting slenderness for plate elements guaranteeing the cross-sectional yield strength. The interactional effect between web plate and flanges is3) Similarly, the limiting slenderness for plate elements of H-sections under the combination of bending and compression was examined by the elasto-plastic finite displacement analysis for solid plated structures. The limiting slenderness for yield strength and also plastic capacity of crossーsections are proposed.4) A new structural steel with low yield ratio (LYR) was developed for the improvement of ductility of high strength steel. The limiting slenderness for plate elements of H-section beams using new mate rial was examined by the FEM analysis. To the limiting slenderness for plastic capacity of cross-section the LYR steel can give some efficiency for the possibility of free design.