锈蚀钢筋混凝土梁承载力退化特性数值分析

Numerical analysis for the degradation of bearing capacity properties of corroded beams

采用ABAQUS有限元软件对一未锈蚀钢筋混凝土简支梁的静力承载性能进行了数值模拟,并与试验结果进行了对比,验证了有限元模型的可靠性。在上述有限元模型的基础上,利用ABAQUS分项计算功能,计算了不同锈蚀程度下钢筋混凝土简支梁的宏观力学特性,计算中分别考虑了锈蚀钢筋黏结滑移性能退化、锈蚀钢筋力学性能退化及二者耦合作用对简支梁承载力及延性退化特性的影响。分析结果表明:随着钢筋锈蚀率的增加,构件的承载力及延性显著降低。轻微锈蚀情况下,钢筋与混凝土之间的黏结滑移性能退化对构件的承载性能无显著影响,而锈蚀引起的钢筋力学性能退化对构件的承载力及延性影响较大。在中等及以上程度锈蚀情况下,黏结滑移性能退化引起的构件承载力和延性退化在构件力学性能退化中占主导地位。总体上看,锈蚀构件的宏观力学特性受到黏结滑移退化及钢筋力学性能退化的耦合影响,随着锈蚀率加大,构件承载力降低,脆性愈加显著。

An uncorroded reinforced beam was analysised with the help of ABAQUS,a finite element software,and comparing with the test result,it was said that,the finit element model is reliable. Base on the finite element model above,using the separate caculation function,macroscopic mechnical properties of different degree corrosion of the beams were caculated,in the caculation,the degradation of bond- slip performance,corroded mechanical performance of bars and the above degradation factors coupling action were taken into consideration that would affect the bearing capacity and ductility of the beams. The analysis result showthat with the increasing of corroded rate,the bearing capacity and ductility of the members is descreased significantly,in the slight corrosion condition,the degradation of bond- slip does not affect the bearing property of beams significantly,but the degradation of corroded bar had a significant affection.In the condition of medium or above corroded rate,the bond- slip degradation would take a leading role to the degradation of bearing capacity and ductility. Overall,the macroscopic mechanical properties of corroded members was affected by the degradation of bond-slip and mechnical properties of bars,with the incrasing of corroded rate,the capacity of members in decreased,and the brittleness is more significantly.