A Study on Ultimate Strength of Folded Steel Plate Girders.

折叠钢板梁极限强度研究。

• 批准号: 14550480
• 负责人: ARIZUMI Yasunori
• 金额: $ 2.18万
• 依托单位: University of the Ryukyus
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14550480/
• 关键词: Folded Steel Plate Girders; Ultimate Strength; Experimental Study; Local Buckling; Finite Element Method; Non-linear analysis; 景観; I形断面鋼桁

In this research, the stability strength of steel plate girders assembled by folded web plates and flange plates under equal end moments about their strong axis are investigated. This paper compares experimental buckling resistances of I-shaped steel girders having unfolded web plates with those of the folded plates. The tests show that the buckling resistances of the girders with folded webs can be higher than those of conventional I-shaped girders.To analyze the ultimate carrying capacity of folded steel plate girders with initial imperfections due to initial deflections and residual stresses caused by welding, an elasto-plastic finite element analysis was used based on geometric and material non-linear isoparametric shell elements. It was assumed that material constitutive relationship follows the Von Mises yield criterion and the Plandtl-Reuss plastic flow rule, combined with material and geometric invariance law, strain hardening law and linear unloading law. The non-linear behavi … More or is solved numerically according to both the Newton-Raphson and the Updated Lagrangian formulations where the displacements increase step-by-step. Actual measurements were used for the initial imperfections of residual stress and initial deflection. The ratio of the test results to analysis results for the ultimate carrying capacity is between 0.98 and 1.028, with an average of 0.996. Thus, it may be concluded that this analysis is quite accurate in evaluating the ultimate load carrying capacity of folded steel plate girders.A parametric study using nonlinear finite element approach is also conducted to evaluate the effects of folded angle, width thickness ratio of plate, slenderness ratio of beam, residual stress and yield stress ratio on the ultimate strength of folded steel plate girders. This paper also presents the instability classification of folded steel plate girders based on the parametric study. Three buckling modes are confirmed, i.e., an inelastic lateral-torsional buckling mode, an inelastic local buckling mode and an interactive buckling of the two. From a parametric study, it appears that the effects of folded web element on the ultimate strength of folded steel plate girders. Less

本研究研究了折叠腹板和翼缘板组装的钢板梁在绕强轴相等端矩作用下的稳定性强度，比较了腹板展开的工字钢梁与腹板展开的工字钢梁的抗屈曲性能。试验表明，折叠腹板梁的抗屈曲能力可以高于常规工字梁。分析初始缺陷的折叠钢板梁的极限承载力。针对焊接引起的初始变形和残余应力，采用基于几何和材料非线性等参壳单元的弹塑性有限元分析，假设材料本构关系遵循 Von Mises 屈服准则和 Plandtl-Reuss 塑性。流动规则，结合材料和几何不变定律、应变硬化定律和线性卸载定律，非线性行为可以根据牛顿-拉夫森和残余应力和初始变形的初始缺陷采用更新的拉格朗日公式，其中位移逐步增加，极限承载力的测试结果与分析结果的比率在0.98和1.028之间。平均值为0.996，因此可以得出结论，该分析在评估折叠钢板梁的极限承载能力方面是相当准确的。使用非线性有限元方法的参数研究是并评价了折叠角度、板宽厚比、梁长细比、残余应力和屈服应力比对折叠钢板梁极限强度的影响，并提出了基于折叠钢板梁的失稳分级。参数研究证实了三种屈曲模式，即非弹性横向扭转屈曲模式、非弹性局部屈曲模式和两者的交互屈曲模式。折叠腹板单元对折叠钢板梁极限强度的影响较小。