摘要
为拓宽单层柱面网壳的应用跨度,以参数分析作为研究手段,利用通用有限元程序ANSYS以及自编的前后处理程序,针对波宽为20m四边支承柱面网壳开展400余例非线性全过程分析,考察屈曲模态、临界荷载、塑性发展分布等特征响应,总结长宽比、矢宽比、初始几何缺陷、荷载不对称分布等因素对网壳临界荷载的影响规律.研究结果显示:四边支承柱面网壳的直杆以受弯作用为主,壳面中部是结构的薄弱区域;当长宽比过大时,应通过增设加劲肋提高壳面刚度,加劲肋的间距应使得网壳长宽比保持在1.0为宜;柱面网壳对于初始几何缺陷较为敏感,当缺陷值达到波宽的1/300时,网壳的弹塑性临界荷载将降低30%以上;当荷载呈不对称分布且p/g=1.0时,网壳的临界荷载将降低到均布荷载作用情况下的86%～94%.
To widen the span range available for single-layer cylindrical reticulated shells, parameter analyses based upon nonlinear complete-process analysis were carried out. More than 400 examples of single-layer cylindrical reticular shells with width of 20 meters and supported along the four edges were calculated by finite element method software ANSYS and self-developed pre- and post-processing programs. The buckling modes, critical loads, plastic development levels were collected to investigate the effect of length-width ratio, rise-span ratio, initial geometric imperfection, and unsymmetrical distribution of loads. The results show that single-layer cylindrical reticular shells supported along the edges are still characterized by bending action, and the central regions of shell structure are the most sensitive areas. When the length-width ratio becomes larger, it is necessary to add the stiffening ribs to enhance the rigidity of shells, and the spacing of which should be set to make the length-width ratio be 1.0. The cylindrical reticulated shells are concluded to be sensitive to initial geometric imperfection, when the initial imperfection value reaches 1/300 of the width, the critical loads of reticulated shell will be reduced by 30%. And when the loads are unsymmetrical distributed with p/g = 1. 0, the critical loads will be 86% -94% of those under symmetrical loading distribution.
出处
《哈尔滨工业大学学报》
EI
CAS
CSCD
北大核心
2010年第10期1524-1529,共6页
Journal of Harbin Institute of Technology
基金
中国博士后科学基金资助项目(20070420876)
国家自然科学基金资助项目(50778054)
关键词
柱面网壳
弹塑性
稳定性
屈曲模态
临界荷载
cylindrical reticulated shells
elasto - plastic
stability
buckling mode
critical load
