摘要
定义节点位置偏差离散度为偏差样本均方差与偏差幅值平均值之比,用以反映缺陷的离散程度.通过关于偏差离散度的参数分析方法,研究节点位置缺陷变离散度对空间网格结构临界荷载的影响规律.采用空间桁架结构作为试验对象,根据结点坐标偏差实测数据,获得更贴近实际模型的统计参数和离散程度,用改进随机缺陷法计算试验结构的临界荷载并与试验结果比较.参数分析和试验验证表明,不同的离散度对空间各网格结构的临界荷载影响较大,改进随机缺陷法采用"2σ原则"基本符合工程实际,但掌握实际结构初始缺陷的离散程度,能够进一步提高结构临界荷载的评估精度.
Discrete degree of node position deviation is defined as the ratio of average variance of deviation samples to mean value of deviation amplitude. It is used to reflect discrete degree of imperfection. The effect of discrete degree of node location imperfection on the critical load of spatial grid structure was studied through the parameter analysis of deviation discrete degree. According to the actually measured data of nodal coordinates deviation of the space truss structure which is introduced as experimental object, statistic parameter and discrete degree can be acquired, which is closer to the actual model. Critical load of experimental structure is calculated with the improved random imperfection. The analysis of the load is compared with the experiment result. Parameter analysis and experiment verification prove that different discrete degree have great effect on critical load of spatial grid structure. Improved random imperfection method by ＂2σ principle＂ basically matches actual construction, however learning the discrete degree of initial geometric imperfection of actual construction can further increase the accuracy of valuation of structural critical load.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2007年第6期1013-1017,共5页
Journal of Southeast University：Natural Science Edition
基金
国家自然科学基金资助项目(10672039)
教育部科学技术研究重点资助项目(105083)
关键词
离散度
初始几何缺陷
正态分布
空间网格结构
临界荷载
discrete degree
initial geometric imperfection
normal distribution
spatial grid structure
critical load
