Diaphragm Effects on Ultimate Strength of Horizontally Curved Thin-Walled Box Girders.

隔膜对水平弯曲薄壁箱梁极限强度的影响。

基本信息

批准号：
08650556
负责人：
ARIZUMI Yasunori
金额：
$ 1.41万
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：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

项目摘要

1.An analytical procedure is proposed to predict ultimate strength and nonlinear behavior of thin-walled, welded steel box-girder curved in plan and stiffened by intermediate interia diaphragms. In the approach, the effects of finite deformation, yielding of material under combined bending and St. Venant's torsioning, unloading caused by strain reversal, spreads of yielding, unloading and reloading zones in the cross-sections and along the gider, and residual stress due to welding are all taken into account in flexure analysis by nonlinear finite element method. How to consider local buckling of component plates and distortional warping in the nonlinear flexure analysis is also proposed.2.The comparison of the analytical with the experimental results on the ultimate strength was judged satisfactory.3.The local buckling of component plates can be evaluated by the proposed model of stress-strain curve allowing for plate buckling as shown in Fig. 3 and this model can be incorporated into … More the nonlinear flexure analysis.4.The breadth of buckling plate can be taken to be width of the compressive flanges of the cross-section of the girder and equal to the depth of the compressive zone of the web plate.5.The constitutive model predicted the local buckling compared well with the experimental results.6.The effect of distortional warping can be simulated in an incremental way at the initial strain-state in the nonlinear flexure analysis, where the strain increments for distortional warping are applied in a step-by-step procedure until an external distortional moment is reached.7.From lower level of loading, bowing deformation which is characterized by covnex form was experimentally confirmed at the compressive part web plate. This phenomenon might be considered to be that the cross-sectional part in compression in the curved girder acts as so-called nonlinear behavior of column with initial crookedness.The above results on the model tests in the conclusions are based on a limited amount of experimental work. Research is clearly needed on the experimental program of larger amount of the model-tests. Though some verification is necessary if the proposed constitutive models allowing for local plate-buckling is to be applied to the girder also stiffened by horizontal and/or vertical stiffeners, the assumed breadth of buckling plate is generally conservative. Less

1.提出了一种分析方法来预测平面弯曲并由中间惯性隔板加固的薄壁焊接钢箱梁的极限强度和非线性行为，该方法中，材料在组合弯曲下的有限变形和屈服的影响。和圣维南扭转、应变反转引起的卸载、横截面和沿梁的屈服、卸载和重新加载区域的扩展，非线性有限元法的弯曲分析中均考虑了焊接产生的残余应力和残余应力，并提出了非线性弯曲分析中如何考虑构件板的局部屈曲和扭曲翘曲的问题。2、分析与实验的比较。极限强度的结果被认为是令人满意的。3.构件板的局部屈曲可以通过所提出的考虑板屈曲的应力-应变曲线模型来评估，如图 3 所示，并且该模型可以合并到......更多非线性4.屈曲板的宽度可取为梁截面受压翼缘的宽度，等于腹板受压区的深度。5.本构模型预测了局部6.在非线性弯曲分析中，可以在初始应变状态下以增量方式模拟扭曲翘曲的影响，其中应用扭曲翘曲的应变增量逐步过程，直到达到外部扭曲力矩。7.从较低的载荷水平开始，在受压部分腹板处通过实验证实了以凸面形式为特征的弯曲变形。曲线梁中受压的横截面部分表现为具有初始弯曲度的柱的非线性行为。结论中的上述模型试验结果是基于有限的实验工作，显然需要进行研究。实验计划尽管如果将所提出的允许局部板屈曲的本构模型应用于也由水平和/或垂直加劲肋加固的梁，则虽然需要进行一些验证，但屈曲板的假设宽度通常是保守.较少