【摘要】 基于特征值屈曲分析理论,结合结构失效准则,针对弦支穹顶结构预应力张拉施工过程中的结构稳定承载力,提出基于有限单元法的特征值迭代法;采用该方法研究具有初始几何缺陷的弦支穹顶结构施工过程的失效模式,提出预应力张拉的失效判别方法及预警参数。计算发现:弦支穹顶结构预应力超张拉失效模式为网壳节点局部跳跃失稳引起整体结构失效,预警参数的下限为结构预应力超张拉下结构的屈曲临界荷载值。所提弦支穹顶结构失效模式和失效预警参数可为实际弦支穹顶结构预应力张拉施工的失效提供科学的预警、预防依据,保障施工安全。更多还原

【Abstract】 Based on the eigenvalue buckling theory for structures combined with structural failure criterion,an eigenvalue iteration method was proposed for calculating stability capacity of suspen-domes with excessive prestress tension.Using the method,the suspen-domes stability capacity and failure modes under excess prestress tension were analyzed,and failure criterion for excessive prestress tension and early-warning parameters were educed in this paper.The results show that the failure mode is the suspen-dome structure failure caused by certain local nodes snap-through firstly and the lower limit value of the early-warning parameter range is the buckling critical load of the structure with excessive prestress tension.The failure modes and early-warning parameters proposed can be a base for early warning for or even preventing suspen-domes failure during prestress tension construction to assure the safety of construction.更多还原