基于双重壳模型的钢筋黏结滑移有限元模拟

Finite element simulation of reinforcement bond-slip effect based on double-shell model

现有的钢筋与混凝土之间的黏结滑移有限元模拟方式存在建模繁琐、计算量大、部分适用条件有限等不足,需要简化和改进。为此,基于ABAQUS有限元分析软件,提出了一种基于双重壳模型的钢筋黏结滑移有限元模拟简易方法。双重壳模型由内嵌于混凝土的极小刚度、厚度的孔道基壳及与实际等弹性模量、等截面积的钢筋壳组成,并在重合的壳-壳界面处设置黏结滑移本构关系。使用此方法分别对钢筋中心拨出试验、梁受弯试验进行了有限元模型验证,并对比其他计算模型和试验数据。结果表明,双重壳模型的计算成本介于实体钢筋模型及钢筋嵌入模型之间,且能有效地模拟钢筋黏结滑移关系;其整体分析结果与试验结果吻合良好;考虑钢筋粘结滑移效应后,构件的刚度有略微降低。故该方法用于RC结构的有限元分析是可行的。

The existing finite element simulation methods of bond-slip between reinforcement and concrete have some shortcomings, such as complicated modeling, large amount of calculation and limited applicable conditions, etc., so it needs to be simplified and improved. Based on ABAQUS software, a simple finite element simulation method for reinforcement bond-slip relationship based on double-shell model is proposed. The double-shell model is composed of a base shell, with minimal stiffness and thickness, embedded in concrete and a reinforcement shell, of equal elastic modulus & cross-sectional area with reality. And the bond-slip constitutive relation is set at the overlapping shell-shell interface. Then, the finite element model verification by the proposed method was conducted for the rebar pullout test and beam bending test. The results show that the calculation cost of the double-shell model is between the solid reinforcement model and the embedded reinforcement model, and it can effectively simulate the reinforcement bond-slip relationship. The overall analysis results are in good agreement with the test results. After considering the reinforcement bond-slip effect, the stiffness of the member decreases slightly. Therefore, the proposed method is feasible for the finite element analysis of RC structures.