单层柱面网壳弹塑性稳定性能研究  

Elasto-plastic stability of single-layer cylindrical reticulated shells

作　　者：曹正罡[1] 孙瑛[1] 范峰[1] 沈世钊[1] 

机构地区：[1]哈尔滨工业大学,黑龙江哈尔滨150090

出　　处：《土木工程学报》2009年第3期55-59,共5页China Civil Engineering Journal

基　　金：基金资助:国家自然科学基金(50778054)

摘　　要：目前对于球面网壳的弹塑性稳定性能研究成果较为丰富,而对柱面网壳的弹塑性稳定性能以及稳定性验算方法中"安全系数"的取值问题还缺乏系统研究。为此,基于有限元软件ANSYS及自编的前后处理程序,有计划地针对600余例单层柱面网壳结构进行双重非线性全过程分析。系统地考察了极限承载力、屈曲模态、塑性发展分布等特征响应,总结了初始几何缺陷和荷载不对称分布等因素对网壳结构稳定性能的影响规律。定义并统计了代表材料非线性影响的"塑性折减系数",基于参数分析结果及概率统计方法对单层柱面网壳的"安全系数"取值进行重新核定,结果显示,柱面网壳塑性折减系数取值范围为0.362～0.578,两纵边柱面网壳安全系数取3.4,四边支承柱面网壳取4.5,两端支承柱面网壳取5.4。Until now, researches about elasto-plastic stability of reticulated domes have gotten fruitful results, but few on the elasto-plastic stability behaviors of cylindrical reticulated shells and the ＇Safety coefficient＇ used in the check of stability are still unknown. Therefore, based on commercial finite element software ANSYS and self- compiled pre-post-processing programs, more than 600 examples of cylindrical reticulated shells are analyzed, using accurate complete-process method with both geometric and material nonlinearity.Some characteristic responses such as critical loads, buckling modes and distribution maps of plastic level are collected. The effects of various geometrical and structural parameters, such as initial imperfection, unsymmetrical distribution of loads, on the behaviors of elasto-plastic stability are investigated. Plastic reduced coefficients are defined to indicate the decrease of stability critical loads of reticulated shells under consideration of material nonlinearity. The plastic reduced coefficients of cylindrical reticulated shells are summarized to be 0.362-0.578. ＇Safety coefficient＇ is then quantified as follows, 3.4 for cylindrical reticulated shells supported along two longitudinal edges, 4.5 for that supported on all boundaries, 5.4 for that supported on two end diaphragms.

关 键 词：单层柱面网壳 稳定 极限承载力 弹塑性 

分 类 号：TU393.3[建筑科学—结构工程]