恒高温下钢管混凝土的界面黏结应力-滑移关系模型研究

Research on Bond Stress-Slip Relationship Model for Interface of Concrete-Filled Steel Tubular Members under the Constant High Temperature

高温下,钢管混凝土的黏结应力-滑移关系模型是进行钢管混凝土结构耐火性能非线性分析的基础.目前国内外对常温下和高温后钢管混凝土的平均黏结强度和黏结滑移关系模型研究相对较多,而高温下钢管混凝土的黏结滑移关系模型研究较少.该文在已有高温下钢管混凝土界面性能试验结果的基础上,提出了高温下界面黏结应力-滑移关系曲线,并通过大量相关试验数据拟合出平均黏结强度及对应的滑移,以及剩余黏结强度与主要影响因素的关系式.与试验结果的对比分析表明:该文提出的高温下黏结应力-滑移关系模型的计算结果和试验结果吻合较好,为进一步研究钢管混凝土耐火性能的精细化有限元分析奠定了基础.

Bond stress-slip relationship model of interface for concrete- filled steel tube(CFST) under high temperature is the basis of nonlinear analysis of CFST structure. At present, the average bond stress and slip relation model of CFST at room and high temperature are paid more attention, while there are the less results of CFST under high temperature. In this paper, based on the experimental results of CFST interfacial performance at high temperature, a reasonable curve of interfacial bond stress-slip relationship at high temperature is presented, the average bond strength and the corresponding slip are fitted by a large number of experimental datas, as well as the relationship between the residual bond strength and the main influencing factors. The comparison with the experimental results shows that, the calculated results of bond stress-slip relationship model in this paper are in good agreement with the experimental results. The results in the paper could lay a foundation for the further research of the fine finite element analysis of fire resistance of CFST.