弹性基底上受非均匀荷载加劲板的局部屈曲特性

发布时间：2018-08-16 10:53

【摘要】：针对弹性基底上板的局部稳定问题,应用能量法推导了非均匀荷载作用下矩形加劲板的局部屈曲非线性特征方程,建立了考虑弹性基底接触和纵向加劲肋作用的屈曲板迦辽金表达式;基于牛顿迭代法,建立了局部屈曲的非线性特征方程的增量迭代格式与屈曲荷载特征值的附加迭代方程。分析结果表明:屈曲系数计算结果与有限元分析结果误差小于2%,并且避免了有限元模拟的接触分析过程,计算效率较高;当荷载梯度为1时,设置加劲肋的偏心构件的局部稳定性明显增强,临界屈曲系数增加到51.1,是普通板件的2.5倍;加劲板件的纵向鼓曲波的长宽比约为0.6,鼓曲波纵向排列相对密集,而普通板件每个鼓曲波的长宽比约为1.0;在不增加加劲肋材料用量的前提下,设置纵向加劲肋的最优位置为距离板件受压侧边缘的2/5板宽处,临界屈曲系数增加为78.9,是普通板件的4倍;加劲肋的设置可将矩形钢管混凝土壁板的宽厚比增加到172,将界限值提高2倍以上。可见,在矩形钢管混凝土管壁设置纵向加劲肋能够有效提高偏压作用下管壁的局部稳定性,改善矩形钢管混凝土的截面尺寸。
[Abstract]:In order to solve the problem of local stability of plates on elastic substrates, the local buckling nonlinear characteristic equations of rectangular stiffened plates under inhomogeneous loads are derived by energy method. The Galerkin expression of buckling plate considering the contact of elastic base and longitudinal stiffening rib is established, and the incremental iterative scheme of nonlinear characteristic equation of local buckling and the additional iterative equation of eigenvalue of buckling load are established based on Newton iteration method. The results show that the error between the calculated results of the buckling coefficient and the results of the finite element analysis is less than 2, and the contact analysis process of the finite element simulation is avoided, and the calculation efficiency is high, when the load gradient is 1, The local stability of eccentric members with stiffened ribs is obviously enhanced, the critical buckling coefficient is increased to 51.1, which is 2.5 times of that of ordinary plates, the aspect ratio of longitudinal drum Qu Bo of stiffened plates is about 0.6, and the longitudinal arrangement of drum Qu Bo is relatively dense. The ratio of length to width per drum Qu Bo is about 1.0, and the optimum position of longitudinal stiffener is about 2 / 5 of the width of plate from the edge of the compressed side of the plate without increasing the amount of stiffener material. The critical buckling coefficient is increased to 78.9, which is 4 times of that of ordinary plate, and the ratio of width to thickness of concrete-filled rectangular steel tube slabs can be increased to 172 by the stiffening rib, and the limit value is increased by more than 2 times. It can be seen that setting longitudinal stiffener on the concrete filled rectangular steel tube wall can effectively improve the local stability of the tube wall under eccentric pressure and improve the section size of concrete filled rectangular steel tube.
【作者单位】：西北农林科技大学水利与建筑工程学院;长安大学陕西省公路桥梁与隧道重点实验室;不列颠哥伦比亚大学土木工程系;
【基金】：国家自然科学基金项目(51378068) 交通运输部建设科技项目(2013 318 812 410) 中央高校基本科研业务费专项资金项目(310821151101)
【分类号】：TU398.9

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