边界条件对薄壁加筋板压缩稳定性能的影响

INFLUENCE OF BOUNDARY CONDITION ON COMPRESSIVE STABILITY PERFORMANCE OF STIFFENED THIN-WALL PANEL

应用非线性有限元方法对加筋板的压缩稳定性进行建模数值计算,通过定义加筋板有限元模型中四边节点的约束条件模拟压缩稳定性试验中承载端简支、固支边界条件以及常用的刀口支持、螺栓顶压、夹板夹持等侧边支持夹具,根据有限元计算结果分析承载端和侧边边界条件对加筋板压缩稳定性能的影响。计算结果表明,当承载端边界约束条件为固支时,结构的屈曲载荷与承载能力均比承载端简支时有一定的增加;当承载端简支时,结构的屈曲形式与破坏失效形式随侧边边界约束条件的不同而不同,相比于侧边自由的情况,侧边施加约束可以增加结构的屈曲载荷与承载能力;当承载端固支时,不同侧边边界约束条件下结构的屈曲形式与屈曲载荷基本相同,相比于侧边自由的情况,侧边施加约束可以增加结构的承载能力。

Nonlinear finite element method（ FEM） was adopted to calculate the compressive stability of stiffened panel numerically. Simple support and clamped support of loaded ends as well as common used unloaded edge support fixtures,such as blade,bolt and rigid strip,for stability experiment were simulated by defining node constraint conditions of 4 edges of stiffened panel finite element model. The influences of boundary conditions of loaded ends and unloaded edges on compressive stability of stiffened panel were analyzed according to the FEM calculational results. Calculational results show that,buckling load and carrying capability of panel with loaded ends clamped are bigger than those of panel with loaded ends simply supported. When loaded ends are simply supported,both buckling pattern and failure pattern vary with different unloaded edge boundary conditions,and buckling loads of panel with unloaded edges supported are bigger than that of panel with unloaded edge free.When loaded ends are clamped,both buckling pattern and buckling load are almost the same despite different unloaded edge boundary conditions,whereas carrying capabilities of panel with unloaded edges supported are bigger than that of panel with unloaded edge free.