结构空间约束对钢筋混凝土梁受弯性能的影响  

The influence of structural spatial constraints on the flexural performance of reinforced concrete beams

作　　者：雷宇霜 金浏[1] 杜修力[1] Lei Yushuang;Jin Liu;Du Xiuli(Faculty of Architecture,Civil and Transportation Engineering,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学城市建设学部,北京100124

出　　处：《东南大学学报（自然科学版）》2024年第4期885-893,共9页Journal of Southeast University：Natural Science Edition

基　　金：北京市自然科学基金资助项目(JQ22025);国家自然科学基金资助项目(51978022)。

摘　　要：为探究结构空间约束对框架结构屈服机制的影响,借助多尺度数值方法,建立了具有不同边界条件的钢筋混凝土(reinforced concrete,RC)梁模型.定量分析了端部约束及添加现浇楼板对RC框架梁刚度和受弯承载力,即试件所能承受的最大弯矩的影响,揭示了端部约束及现浇楼板对RC梁弯曲机制的影响机理.此外,对各国规范计算的受弯承载力进行对比分析.结果表明,结构空间约束会影响RC框架梁的破坏形态.固支梁的刚度和受弯承载力显著高于简支梁,固支梁的受弯承载力和刚度最高可达简支梁的3.06倍和4.10倍.添加现浇楼板可显著提高梁的受弯承载力与刚度.各国规范可准确地计算简支梁的受弯承载力.然而,计算的固支梁及楼盖梁的受弯承载力极其保守,剪跨比为5.0的固支加板梁的受弯承载力模拟值分别是中国、美国和加拿大规范值的6.25倍、6.76倍和6.06倍.To investigate the influence of structural spatial constraints on the yielding mechanism of frame structures,reinforced concrete(RC)beam models with different boundary conditions were established using a multiscale numerical method.A quantitative analysis was conducted on the influence of end constraints and the addition of cast-in-place floor slabs on the stiffness and flexural capacity of RC frame beams,i.e.,the peak bending moment that the specimen can withstand.The influence mechanisms of end constraints and cast-in-place floor slabs on the bending mechanism of RC beams were revealed.Furthermore,comparative analyses were conducted with the calculated flexural capacity of various national standards.The results indicate that structural spatial constraints affect the failure modes of RC frame beams.The stiffness and flexural capacity of fixed-end beams are significantly higher than those of simply supported beams,with the flexural capacity and stiffness of fixed-end beams reaching up to 3.06 and 4.10 times those of simply supported beams,respectively.The addition of cast-in-place floor slabs significantly enhances the flexural capacity and stiffness of the beams.National standards can accurately calculate the flexural capacity of simply supported beams.However,for fixed-end beams and floor beams,the calculated flexural capacity is extremely conservative.For example,the simulated values of fexural capacity for the fixed-end beam with a shear span ratio of 5.0 are 6.25,6.76 and 6.06 times the calculated values according to Chinese,American,and Canadian standards,respectively.

关 键 词：钢筋混凝土梁 结构空间约束 端部约束 现浇楼板 强梁弱柱 细观模拟 

分 类 号：TU375.1[建筑科学—结构工程]