【作者】 谭璐；

【导师】 张川；

【作者基本信息】 重庆大学 ， 结构工程， 2008， 硕士

【摘要】 本文的研究是关于钢筋混凝粘结-滑移性能的有限元模拟,分析中假定这类构件可用平面应力场描述。采用不同的材料本构模型来模拟构件中的混凝土和纵钢,这两种材料之间的界面性能通过粘结-滑移模型来描述,粘结-滑移模型把混凝土和钢筋这两种材料模型联系起来,反应钢筋混凝土复合材料的性能。围绕上述内容本文开展的主要工作如下:①在已有研究基础上,选用基于等效单轴应变的增量式正交异性混凝土模型来模拟混凝土四结点等参元。混凝土的应力-应变关系采用考虑了受拉硬化的反复拉压加载滞回本构模型。②在纵筋布置处的混凝土单元之间增加结点,插入考虑了钢筋Baushinger效应的Seckin钢筋滞回本构来描述钢筋杆单元的应力-应变关系。③在上述两种模型的界面上插入自编的粘结-滑移模型来考虑它们之间的粘结-滑移作用。粘结-滑移单调模型直接采用了Eligehausen et al.(1982)的建议,滞回模型主要以滕智明的滞回规则为基础,参考Eligehausen et al.(1982)关于锚固钢筋在反复荷载作用下粘结-滑移滞回关系的试验结果,以此为依据修改了滕智明模型滞回路径中某些控制点的取值。④本文以FEAPpv(Finite Element Analysis Program Personal Version)这一有限元源程序为分析平台,在用户自定义的单元模块上,添加已有的钢筋混凝土单元,自编的钢筋杆单元,联结弹簧单元。在自定义材料模块上,添加上述三部分的本构模型。在FEAPpv中成功地实现了三部分的整合,采用源程序提供的支座位移控制加载进行求解。⑤运用此程序计算Viwathanatepa, Eligehausen等人的锚固钢筋试件,并与试验结果进行对比,验证不同加载制度下,采用本文的粘结-滑移模型,模拟锚固钢筋粘结-滑移性能的准确程度。研究粘结-滑移性能对不同锚固长钢筋受力性能的影响程度,以及不同钢筋直径和混凝土强度对粘结-滑移作用的影响。⑥分别采用不考虑粘结-滑移作用的整体式模型和考虑粘结-滑移作用的分离式模型,计算承受跨中集中荷载作用的钢筋混凝土简支梁的荷载-挠度曲线,并将其结果进行对比分析,研究粘结-滑移作用对适筋梁和超筋梁受力性能的影响程度。⑦从局部和整体两个层次上验证了程序分析结果的有效性,以及程序所采用模型的可靠性和确定参数的合理性。为本研究组一直以来进行的钢筋混凝土二维有限元分析的研究,提供了可直接调用的联结单元,以及低周反复荷载作用下的粘结-滑移滞回本构模型。更多还原

【Abstract】 This thesis concerns about simulating bond-slip relationships in reinforced concrete using finite element method. It is assumed that it can be treated as a plane stress problem. Different material models are used to simulate concrete and longitudinal steel. And link element is inserted between the two models to simulate bond between concrete and longitudinal steel.The main contents of the thesis are as following:①Based on the previous research on this point, equivalent uniaxial strain model for concrete was chosen, tension stiffening effect was taken into account in the concrete strain-stress relationship.②Nodes were added between longitudinal steel and concrete element. Seckin’s model was used in which the Baushinger effect is considered to represent the train-stress relationship of the longitudinal steel.③Bond-slip model were established by the author to describe the relationship between concrete and longitudinal steel. Eligehausen’s model was adopted under monotonic loading .Bond-slip model under reversed cyclic loading was based on Teng zhiming’s model. Bsed on Eligehausen’s testing results, some parameters of Teng zhiming’s model were refined.④On the basis of previous research in our group, concrete, steel and bond limk elements were integrated into FEAPpv (Finite Element Analysis Program Personal Version) to form user-defined element module and their strain-stress models were integrated to form material module. Displacement controlled loading algorithm which provided by FEAPpv was used in the program.⑤Testing results of anchoraged steel under monotonic and cyclic loading conducted by Viwathanatepa, Eligehausen et al were used to verify the above- mentioned bond-slip models. The effect of anchorage length on steel behavior, bar diameter and concrete strength on bond-slip relationships are evaluated.⑥Two different models,one is the integrated model without considering bond-slip and the other is the discrete model, were used to simulate load-deflection response of simply-supported RC beams.Effect of bond-slip on both under-reinforced and over-reinforced concrete beams was recognized.⑦Comparison of the computed results with tested ones was carried out in both loacl and overall responses to verify the finite element modelling of bond-slip in this thesis.The link element to simulate bond-slip, together with hysteretic rules under reversed cyclic loading ,are available to carry out realistic nonlinear finite element analysis.更多还原