杆件初弯曲对网壳结构弹塑性稳定性能影响研究  

Research on influence of initial curvature of members on elasto-plastic stability of reticulated shells

作　　者：严佳川[1] 范峰[1] 曹正罡[1] 

机构地区：[1]哈尔滨工业大学土木工程学院,黑龙江哈尔滨150090

出　　处：《建筑结构学报》2012年第12期63-71,共9页Journal of Building Structures

基　　金：国家自然科学基金面上项目(50778054);黑龙江省青年科学基金项目(QC2010109);黑龙江省博士后科研启动基金项目

摘　　要：为研究杆件初弯曲对网壳结构弹塑性稳定性能的影响,采用多段梁法模拟杆件的初弯曲,通过ANSYS软件给出2种建模方法引入网壳结构的杆件初弯曲。根据杆件初弯曲的随机性介绍随机缺陷模态法,以Kiewitt-8型网壳为例解释随机缺陷模态法的模拟过程并考察杆件初弯曲方向角和幅值随机变量对网壳稳定性的影响,由此得到修正的一致缺陷模态法。基于上述方法,分析考虑杆件初弯曲的Kiewitt-6、Kiewitt-8和短程线型单层网壳的稳定性,定量给出杆件初弯曲对不考虑节点偏差结构和考虑节点偏差结构承载力的影响。结果表明:对于不考虑节点偏差结构和考虑节点偏差结构,杆件初弯曲将明显降低结构承载力,并且能够改变结构的塑性发展程度,杆件初弯曲对单层网壳弹塑性稳定性能的影响不可忽略;修正的一致缺陷模态法能够有效评估考虑杆件初弯曲的网壳结构承载力的较小值。To investigate the influence of initial curvature of members on the elasto-plastic stability of single-layer reticulated shell structures,the multi-beam method was adopted to model the initial curvature of members,and based on the FEA package ANSYS,two methods were proposed to introduce the initial curvature of members of reticulated shells.According to the randomness of initial curvature of members,the random imperfection mode method was presented.Taking a Kiewitt-8 dome as an example explained the simulation process of the random imperfection mode method,and investigate the influence of direction angle and amplitude random variables of initial curvature of members on the stability of the reticulated shell structure.From the result of the random imperfection mode method,the modified consistent imperfection mode method was established.Then,based on this method,the stability of the Kiewitt-6,Kiewitt-8 and geodesic single-layer reticulated shells considering the influence of initial curvature of members were analyzed.For the structure without and with nodes deviation,the influences of initial curvature of members on the bearing capacity of the structures were obtained quantitatively.The results show that,for the structure without and with nodes deviation,the initial curvature of members can decrease the bearing capacity of the structure obviously,and change the degree of plasticity development of the structure.The influence of initial curvature of members on the elasto-plastic stability of single-layer reticulated shells cannot be neglected,and the modified consistent imperfection mode method is effective to estimate the lower bearing capacity of the reticulated shell structures considering the influence of initial curvature of members.

关 键 词：单层网壳 稳定 杆件初弯曲 有限元分析 承载力 

分 类 号：TU393.3[建筑科学—结构工程] TU311.41