钢筋混凝土梁柱节点核心区计算模型研究

梁柱节点核心区受力复杂,修正斜压场理论和斜压杆模型均存在一定的不足,基于前人对斜压杆机制和软化桁架机制的研究,提出梁柱节点核心区受剪承载力新计算模型,即斜压杆机制和软化桁架机制承担的水平剪力按一定比例组合的计算模型。该模型既可以计算节点核心区的受剪承载力,还可以验算节点核心区混凝土抗压强度,计算水平配箍率。将国内外82个试件的节点最大剪应力试验值与该方法所得的节点最大剪应力计算值比较得出:均值为1.154,变异系数为0.131。较试验值与软化拉-压杆模型计算值之比结果相比,离散性较小,验证了此方法的可行性。

STUDY OF CALCULATION MODEL OF REINFORCED CONCRETE BEAM-COLUMN JOINT CORE

Stress of beam-column joint is complex, and modified compression field theory and the diagonal compression strut model have some shortages. Based on predecessors' study on the diagonal compression strut mechanism and softened strut-and-tie mechanism,a new calculation model of shear capacity of beam-column joint core was proposed,where the horizontal shear carried by both the diagonal compression strut mechanism and softened strut-and-tie mechanism was combined by a certain percentage. According to the proposed model,the shear capacity of beam-column joint core was calculated,concrete compressive strength and horizontal stirrup ratio were also computed. Experimental value of largest shear stress of 82 specimens at home and abroad was compared with calculated value using the method,and the mean ratio of experimental value to calculated value by the method was1. 154 with coefficient of variation of 0. 131. The discreteness of experimental value to calculated value by the method was smaller than that of experimental value to calculated value by softened strut and tie model,and the feasibility of the method was verified.