短深大板梁常在钢结构工业厂房中用于支撑重型设备,这类构件跨高比通常在5左右.由于腹板跨高比较大,其抗剪承载能力对构件的整体承载力性能有很大影响.然而,现有设计方法对剪力比大于0.5的构件考虑不足.为此,设计完成了4个短深大板梁试件的静力加载试验,并验证了相应的有限元模拟方法.试验及有限元分析结果表明,大板梁主要有两类破坏模式,分别称做“弹塑性整体失稳破坏”和“腹板局部失稳破坏”.由于板梁构件具有明显的局部-整体相关性,现有的截面分类设计方法及其遵循的“单一板件准则”针对其适用性较差.结合钢结构构件设计的发展,将构件分类设计方法拓展到了短深大板梁的范围.建议首先根据构件的设计参数预测构件的破坏模式,然后采用相应的承载力计算方法进行设计.%In industrial plants of steel structure,steel plate girders are commonly used to support massive weight equipment.The span-depth ratios of these girders are generally around 5.Because of large span-depth ratio of web,the shear resistances of these girders have great influences on their load-bearing capacities.Therefore,the interaction of shear buckling with other instability modes for the classification purpose (i.e.,the selection of the analysis procedure) should be examined especially for I-section girders with high shear ratio (i.e.,the shear force is greater than half of the plastic shear resistance).Static loading tests are carried out on four specimens,and the corresponding finite element simulations are verified.Experimental and FE simulation results disclose that there are two major failure modes,namely,elasto-plastic global buckling mode and local buckling mode of web.Due to the obvious local-global correlation of plate girders,the applicability of existing classification and design methods of cross section and its obeyed "rule of single plate member" to the plate girders is not good.Based on the development of the design of steel structure and members,the classification and design methods of members can be extended to short-deep plate girders.It is recommended that the failure modes of members shall be predicted according to the design parameters of members firstly,and then the designs shall be carried out according to the corresponding calculation methods of bearing capacity.
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