锈蚀焊接空心球节点随机抗压承载力研究

焊接空心球节点(WHSJs)自1966年被提出以来，已经广泛地应用于空间网格结构中，至今已有55年的应用历史。由于环境的侵蚀、后期维护不到位等，焊接球节点锈蚀的现象屡见不鲜。该文针对随机锈蚀后焊接空心球节点的抗压承载力的变化规律进行了研究，基于随机有限元分析方法进行了大量的随机数值分析，研究了锈蚀深度概率分布模型对抗压承载力折减系数的影响；利用曲线拟合技术提出了折减系数下限和上限曲线的理论计算公式；通过随机有限元的大量分析结果揭示了抗压折减系数随锈蚀深度概率分布模型的变化规律；提出了用于预测抗压折减系数概率分布模型的拟合公式；通过对具有不同几何参数的焊接空心球节点的分析，得到了该文结论对不同几何尺寸下焊接球节点的适用性。研究结果表明，所提出的方法可以准确确定随机锈蚀焊接空心球节点抗压承载力折减系数的随机概率分布模型，可为随机锈蚀焊接球节点承载力的评估提供理论分析基础。

RANDOM COMPRESSION CAPACITY OF CORRODED WHSJS

The welded hollow spherical joint (WHSJ) has been widely utilized in reticulated shell structures for 55 years since it was put forward in 1966. The corrosion of WHSJs can always be observed in actual conditions due to the invasion of surrounding environment and the unqualified maintenance. We investigate the axial compression capacity of randomly corroded WHSJs. Numerous numerical analysis was performed based on the stochastic finite element analysis. The influence of the probabilistic distribution model of corroded thickness on the reduction factor of the compression capacity of WHSJs was investigated. Analytical formula for predicting the reduction factor were proposed by curve fitting. The influence of the probabilistic distribution model of the corroded thickness on the changing rule of the reduction factor was revealed based on the numerous results derived from the stochastic numerical analysis. The fitting formula which can be used to predict the probabilistic distribution model of the reduction factor was proposed. The applicability of the conclusions on WHSJs with different geometrical sizes was validated through the results derived from WHSJs with different geometrical parameters. The results indicate that the proposed method can accurately determine the probabilistic distribution model of the reduction factor and the conclusions provide an analytical foundation for estimating the compression capacity of randomly corroded WHSJs.