钢纤维混凝土纤维拔出的数值模拟

发布时间：2018-06-08 23:47

本文选题：钢纤维 + 混凝土　；参考：《东北大学》2014年硕士论文

【摘要】：钢纤维增强混凝土材料因其优良的力学性能,广泛应用于桥梁、建筑和水利等工程实际环境,因此研究钢纤维混凝土的力学性能是现代工业发展的必然需求。而界面脱粘滑移模型作为钢纤维混凝土力学性能核心的内容,仅仅通过实验研究其力学性能有一定程度上的困难。本文在不考虑混凝土破坏的前提下,利用ANSYS软件,用有限元法分析了钢纤维从混凝土基体中拔出的过程,为钢纤维混凝土的断裂韧性研究提供了依据。本文首先建立了平直钢纤维混凝土的有限元模型。为了考虑纤维与混凝土界面层的属性影响,在纤维与混凝土间设置界面层,利用节点耦合和解耦合的方法模拟纤维与混凝土的粘结和脱粘作用,以界面切应力强度准则作为纤维脱粘的判断依据,实现对平直钢纤维拔出混凝土过程的模拟,并与试验结果对比。研究了界面弹性模量、纤维直径和纤维埋深对界面应力分布的影响。进而分析界面切应力强度、界面弹性模量和界面摩擦应力对平直纤维拔出特性的影响。其次本文利用接触单元模拟纤维与混凝土的接触界面,忽略混凝土基体破坏的影响考虑纤维的塑性变形,对端钩型钢纤维拔出混凝土过程进行研究,并与试验结果比较。分别讨论了界面摩擦系数、基体弹性模量、钢纤维的抗拉强度和混凝土收缩对纤维拔出特性的影响。最后本文由纤维拔出的位移载荷曲线得到纤维拔出过程中的耗能量,讨论不同埋置角和不同尺寸端钩钢纤维拔出耗能的变化规律,对端钩纤维单丝拔出的拔出耗能做出合理预判。
[Abstract]:Steel fiber reinforced concrete (SFRC) is widely used in bridges, buildings and water conservancy projects because of its excellent mechanical properties. Therefore, it is necessary to study the mechanical properties of SFRC in modern industry. As the core of the mechanical properties of steel fiber reinforced concrete, it is difficult to study the mechanical properties of the interface debonding slip model only by experiment. In this paper, without considering the failure of concrete, the process of pulling steel fiber out of concrete matrix is analyzed by using ANSYS software and finite element method, which provides a basis for the study of fracture toughness of steel fiber reinforced concrete (SFRC). In this paper, the finite element model of straight steel fiber reinforced concrete (SFRC) is established. In order to consider the effect of the properties of fiber and concrete interface layer, the bond and debonding between fiber and concrete is simulated by using the method of node coupling and coupling. Based on the criterion of interfacial shear stress strength as the criterion of fiber debonding, the simulation of concrete pull-out process of straight steel fiber is realized, and the results are compared with the experimental results. The effects of interfacial elastic modulus, fiber diameter and fiber depth on the interfacial stress distribution were studied. The effects of interfacial shear stress strength, interfacial elastic modulus and interfacial friction stress on the pull-out characteristics of straight fiber were analyzed. Secondly, the contact element is used to simulate the contact interface between the fiber and the concrete. The plastic deformation of the fiber is taken into account, and the process of drawing out the end hook steel fiber is studied, and the results are compared with the experimental results. The effects of interfacial friction coefficient, elastic modulus of matrix, tensile strength of steel fiber and shrinkage of concrete on the pull-out characteristics of the fiber were discussed. Finally, from the displacement load curve of fiber pull-out, the energy consumption of fiber pull-out process is obtained, and the variation law of pull-out energy of steel fiber with different burying angle and different size is discussed. To the end hook fiber single filament pull-out energy consumption to make a reasonable prediction.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528.572

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