CFRP布加固RC柱细观力学分析模型及抗扭分析  

Meso-scale Mechanical Analysis Model of CFRP Sheet-reinforced RC Columns and Torsional Analysis

作　　者：金浏[1] 籍一丁 李冬[1] 雷宇霜 杜修力[1] JIN Liu;JI Yiding;LI Dong;LEI Yushuang;DU Xiuli(Key laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124

出　　处：《北京工业大学学报》2024年第11期1339-1349,共11页Journal of Beijing University of Technology

基　　金：北京市自然科学基金资助项目(JQ22025);北京市科技新星计划资助项目(20220484047)。

摘　　要：为了探究配纤率、截面形状、截面尺寸、轴压比对碳纤维增强复合材料(carbon fiber reinforced polymer,CFRP)加固钢筋混凝土(reinforced concrete,RC)柱抗扭性能的影响,采用了可以同时考虑混凝土材料非均质性、钢筋与混凝土间黏结-滑移关系、CFRP布与混凝土间界面关系的细观力学分析方法。首先,建立了用于CFRP布加固RC柱抗扭性能分析的三维数值模型;进而,将基于该模型的数值模拟结果与试验结果对比,验证了模型中加载方式、外贴CFRP布方法的合理性及材料参数的准确性;最后,基于建立的细观力学分析模型,探讨了配纤率、截面形状、截面尺寸、轴压比对扭转作用下CFRP布加固RC柱破坏模式和力学性能的影响机制。分析结果表明:CFRP布加固RC柱抗扭承载力随配纤率增大而提高,但提高幅度随配纤率增大而降低;受到围压分布的影响,圆形截面的有效约束面积大于方形截面,使得CFRP布对圆柱的约束效果好于方柱;CFRP布加固RC柱的名义扭转强度存在尺寸效应;轴压比的增大使其抗扭承载力先增大后减小,在轴压比为0.4时达到最大值。进一步,采用叠加规范公式方法提出了FRP布加固RC构件抗扭承载力计算公式,与数值模拟结果对比发现,该公式可给出安全储备冗余度30.2%的设计值,可初步用于CFRP布加固RC柱抗扭承载力的安全设计。To explore the effects of fiber ratio,cross-sectional shape,cross-sectional size and axial compression ratio on the torsional performance of carbon fiber reinforced polymer(CFRP)-reinforced concrete(RC)columns,this paper employs a meso-scale mechanical analysis method that can simultaneously consider the heterogeneity of concrete,the bond-slip relationship between reinforcement and concrete,and the interfacial relationship between CFRP sheets and concrete.First,a three-dimensional numerical model was established for the analysis of the torsional performance of CFRP sheet-reinforced RC columns.Subsequently,the numerical simulation results based on this model were compared with the experimental results to verify the rationality of the loading approach and the method of externally bonded CFRP sheets,and the accuracy of material parameters.Finally,based on the meso-scale mechanical analysis model,the influence mechanism of the fiber ratio,cross-sectional shape,cross-sectional size and axial compression ratio on the failure modes and mechanical properties of CFRP sheet-reinforced RC columns under torsion was investigated.Results show that the torsional bearing capacity of RC columns increases with the increase of fiber ratio,but the improvement rate decreases with the increase of fiber ratio.Influenced by the distribution of confining pressure,the effective restraint area of the circular section is larger than that of the square section,making the restraint effect of CFRP sheet on the circular column better than that of the square column.The size effect can be observed in the nominal torsional strength of CFRP sheet-reinforced RC columns.The torsional bearing capacity firstly increases and subsequently decreases with the increase of the axial compression ratio,and reaches its maximum capacity at n=0.4.Furthermore,a calculation formula for the torsional bearing capacity of FRP sheet-reinforced RC members is proposed by superposing specification formulas.Compared with the numerical simulation results in this paper,the f

关 键 词：RC柱 CFRP布 细观模型 数值模拟方法 抗扭分析 承载力计算 

分 类 号：TU375[建筑科学—结构工程]