【作者】 沙鹏；

【导师】 李晓延；

【作者基本信息】 北京工业大学 ， 材料加工工程， 2003， 硕士

【摘要】 本文用MSC.Marc大型有限元软件建立了钢筋混凝土复合材料的嵌入模型。模拟了适筋梁和超筋梁的加载过程，并研究了适筋梁和超筋梁各自的力学特性。通过计算得出了钢筋混凝土结构受力后的应力分布云图，找出了结构的危险部位。在使用钢筋混凝土结构时，可选的钢筋和混凝土强度匹配种类很多。本文计算了混凝土C30-C50与Ⅱ、Ⅲ级钢筋每一种强度匹配情况下的力学特性，为工程师选用钢筋和混凝土强度等级组合时提供了依据。通过钢筋混凝土的腐蚀试验，本文研究了局部锈蚀钢筋和全部锈蚀钢筋在钢筋混凝土结构中的力学退化性能，并用“坑蚀”和“剥层”的有限元模型对其进行了数值分析。最后本文对北京市一座在役道桥的T型梁，进行了有限元模拟，对其受力状况进行了评估。研究表明：用三维有限元模型能够成功模拟适筋梁和超筋梁的力学行为，其结果和理论值与试验值一致，计算精度令人满意。说明本文所采用的简化模型是合理的，可靠的。在道桥常用的混凝土牌号与Ⅱ、Ⅲ级钢筋的强度匹配中，力学性能由好至劣的顺序为：C50-Ⅲ、C45-Ⅲ、C40-Ⅲ、C35-Ⅲ、C30-Ⅲ、C50-Ⅱ、C45-Ⅱ、C40-Ⅱ、C35-Ⅱ和C30-Ⅱ。“脱层”模型可以用于对全面锈蚀钢筋力学退化特性的模拟。同一载荷下，钢筋混凝土梁的纵向位移随着梁内钢筋全面锈蚀深度的增加而增加。从而说明了锈蚀钢筋将大大降低钢筋混凝土结构的承载能力。更多还原

【Abstract】 Finite element analysis was used to simulate the stress-strain behavior of reinforced concrete beams via a composite model. The mechanical response of the appropriate reinforcement beam and the surplus reinforcement beam, which were loaded in the experiment conditions, was computed. The potential critical failure area of the reinforced concrete beams was analyzed by the detail study of the stress distribution. In the design of the reinforced concrete structures, the strength grade from C30 to C50 of concrete is usually matched with Grade II and III of steel bars. The mechanical characteristics of the above groups of matching have been investigated. Corrosion behavior was studied both by experimental and numerical approaches. The mechanical properties of partial corrosion and entire corrosion in the reinforced concrete structure were analyzed. Dot Corrosion and Delamination models were employed during the simulation. Finally, the mechanical properties of a T-beam of an actual bridge have been analyzed. Results show that the use of the 3-D finite element model is suitable and the precision of the simulation is acceptable. It was found that the load carrying capacity, from high to low, of different matching of the concrete and steel bar is as follows: C50-III, C45-III, C40-III, C35-III, C30-III, C50-II, C45-II, C40-II, C35-II and C30-II. "The Delaminating Model" could be adopted to simulate the condition of entire corrosion on steel bars. The corrosion of the steel bars in the concrete has important influences on the load carrying capability of the reinforced concrete structures.更多还原