偏心钢结构节点梁柱-核心区受力机理研究

INTERACTION EFFECT BETWEEN A BEAM OR COLUMN AND THE CORE AREA OF AN ECCENTRIC STEEL JOINT

某些工程处于建筑布置和使用的需要而采用钢结构偏心连接节点。偏心节点由于受到扭转作用,而在节点核心区产生较为明显的应力集中。该文借助有限元模型,对偏心连接梁-柱钢结构节点的受力特征进行分析,表明偏心节点核心区存在明显的三维扭转效应,以及梁柱截面的畸变翘曲效应。在受力特征分析的基础上,提出了钢结构偏心节点核心区的耦合效应计算模型。通过与有限元模型进行比对验证和参数分析,对梁柱截面畸变角函数进行修正和标定。分析表明,该文提出的偏心节点核心区耦合效应分析方法能够较准确计算梁柱截面畸变翘曲正应力与弯曲正应力,可供设计参考。

Eccentric beam-column steel joints can be used to enhance the flexibility of building layouts. However, the eccentricity can cause stress concentrations, and has a negative influence on the mechanical properties of the joints. This paper presents a study of the mechanical performance of steel eccentric beam-column joints using FE models. The three dimension torsion effect is proved to exist in eccentric steel joints, while distortion and warping is observed to exist in sections of the beams and columns. A series of simplified assumptions were made based on the mechanical performance analysis, and a model focusing on the interaction effect between the beam or column and the core area of the eccentric joint is proposed. The simplified assumptions of the model were compared with the mechanical performance obtained from the FE models, and a revised coefficient is adopted for the distortion angle in order to coincide with the character of the distortion angle in the FE models. The proposed model in this paper is accurate when predicting the ratio of the distortion warping stress and the bending stress.