基于MCFT的钢筋增强ECC梁受剪承载力计算方法  

Calculation method for shear strength of reinforced ECC beams using modified compression field theory

作　　者：乔治[1] 潘钻峰[2] 梁坚凝[3] 孟少平[1] Qiao Zhi;Pan Zuanfeng;Leung C K Y;Meng Shaoping(School of Civil Engineering,Southeast University,Nanjing 210096,China;College of Civil Engineering,Tongji University,Shanghai 200092,China;School of Civil Engineering,Hong Kong University of Science and Technology,Hong Kong,China)

机构地区：[1]东南大学土木工程学院,南京210096 [2]同济大学土木工程学院,上海200092 [3]香港科技大学土木与环境工程系

出　　处：《东南大学学报（自然科学版）》2018年第6期1021-1027,共7页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金青年基金资助项目(51208093);国家自然科学基金委员会-国际交流资助项目(5141101015);教育部博士点基金资助项目(20120092120021)

摘　　要：基于修正斜压场理论(MCFT)和ECC的材料特性,建立了适用于计算RECC梁受剪承载力的修正MCFT方法.该方法将开裂后的ECC看作一种连续材料,对ECC构件斜向开裂后的平均主应力-应变关系和局部应力平衡方程进行了修正,考虑了拉压双轴受力下的软化本构关系以及裂缝间ECC的纤维桥接作用.建立了40根RECC梁和6个RECC板的剪切试验数据库,对提出的RECC梁受剪承载力修正MCFT方法进行了验证,结果表明该方法具有较高的计算精度.通过合理简化,推导了斜压杆角度和主拉应变的显示计算公式,进而提出了有腹筋RECC梁受剪承载力的简化计算方法,该方法无需迭代计算.利用数据库对该简化方法进行评估,试验强度与计算强度比值的均值及变异系数分别为1. 05和0. 197,表明其预测精度良好.Based on the modified compression field theory(MCFT)and the characteristics of engineered cementitious composites(ECC),a modified MCFT method for calculating the shear capacity of RECC beams is established.In this method,cracked ECC was regarded as new continuous material,and averaged principal stress-strain relationships and local stress conditions at crack locations for ECC were modified,considering the stress-strain relationship under biaxial stress state and the fiber bridging action on the crack plane.A database was established for the shear tests of 40 RECC beams and 6 RECC slabs,and then the modified MCFT method for the shear capacity of RECC beam were evaluated.Results indicate that the modified MCFT method is of high accuracy.Through reasonable simplification,the expression for the inclination of ECC strut and the principle tensile strain was explicitly derived,and a simplified calculation method without iterative calculations for the shear strength of RECC beam with stirrups was further proposed.The simplified method was then evaluated by the database.Results show that the mean value and coefficient of variation of the ratio of test strength to predicted strength are 1.05 and 0.197,respectively,indicating that the calculation accuracy of the simplified method is good.

关 键 词：工程用水泥基复合材料 梁 受剪承载力 修正斜压场理论 斜压杆角度 

分 类 号：TU375.1[建筑科学—结构工程]