U肋加劲板受压力学性能分析

为了探究U肋加劲的板件在压力作用下的受力性能与破坏机理,建立了受压混合钢U肋加劲板非线性有限元模型,分析了边界条件、初始几何缺陷和焊接残余应力对其受力性能的影响。结果表明:改变试件两端的转动约束条件会改变试件的破坏模式和受压稳定承载力;加载偏心方向对试件稳定承载力有较大的影响,当加载偏心弯矩效应与试件弯曲方向一致时,试件承载力随加载偏心的增大而减小,反之,试件承载力随加载偏心的增大而增大;在有限元模型中试件两端约束设置为自由转动,整体几何缺陷幅值取构件长度的1/1 000,局部几何缺陷幅值取子板宽的1/200,加载偏心矩取截面高度的0. 02倍,采用残余应力简化分布形式得到的承载力计算结果与混合钢U肋加劲板试验结果符合较好。该数值模拟方法可用于混合钢U肋加劲板的受力性能和抗压稳定承载力分析。

Analysis of Compression Mechanical Behavior for U-Rib Stiffened Plate

In order to study the mechanical behavior and failure mechanism of U-rib stiffened plate under the action of compression,a nonlinear f inite element model for compressed mixed steel U-rib stiffened plate was established,in which the inf luence of boundary condition,initial geometric imperfections and welding residual stresses on the mechanical properties were analyzed.The results show that the failure mode and compressive stability bearing capacity of specimens can be changed by changing the rotational constraints at both ends of specimens.The loading eccentricity has a great inf luence on the compressive stability bearing capacity of the specimen.When the bending moment effect induced by the eccentric load coincide with the curvature of the specimen,the bearing capacity of the specimen decreases with the increase of the load eccentricity;conversely,the bearing capacity of the specimen increases with the increase of the load eccentricity.When the constraints at both ends of the specimens are set to rotate freely in the f inite element model,the magnitude of the overall geometric defects is 1/1 000 of the length of the specimen,the magnitude of the local geometric defects is 1/200 of the width of the sub-plate,and the eccentric moment is 0.02 times of the height of the cross section,the calculation results of the bearing capacity obtained by simplif ied residual stress distribution are in good agreement with the test results of the mixed steel U-rib stiffened plate.The numerical simulation method can be used to analyze the mechanical properties and compressive stability bearing capacity of mixed steel U-rib stiffened plates.