Reinforcement Mechanism Of External Pre-stressed Concrete

In recent years, the technology of Structural reinforcement is developing rapidly in China and begin to take shape. Reinforcing technology as a new discipline is forming. In vitro pre-stressed reinforcement technique as a method of strengthening the initiative, and its essence is using crude steel or high-strength steel wire strand such as a load of steel tools. Pre-stressed structure imposed on the in vitro. Use of the anti-pre-tension moment offset part of the loading forces, thereby improving the structure to improve its performance, and the purpose of ultimate strength.In this paper ,through theoretical analysis and numerical simulation methods, the increment of stress calculation,reinforcement mechanism,reinforcement design and its evaluation to the concrete beam with external pre-stressed is made a detailed analysis and research. At the same time using nonlinear finite element analysis simulation of in vitro pre-stressed concrete beams, such as the loading process. This is not only an important theoretical significance, but also for practical application has a high value .It provide the basis for design of pre-stressed reinforcement, and will be conducive to a more reasonable design, improve structural performance. Specific content:Firstly. Pre-stressed in vitro system is introduced in detail, such as in vitro pre-stressed beams main materials, casing, anchoring system, steering and shock absorption devices. Then in the reinforcement methods, the layout of the different type beam effect on the reinforcement structure and layout principles make a systems analysis .At same time ,the forced acts of pre-stressed beams in vitro by the shift are carried out the calculation and analysis.Secondly. For in vitro pre-stressed reinforced concrete beam, the author make a detailed analysis and calculation .Such as the bending calculation of simple beams,continuous beams and frame beams ,the deflection of considering secondary effects and not considering the secondary effects, Analyzing the behavior of external pre-stressed reinforcement indeterminate beams , including a second moment principle and calculation.Thirdly. On the basis of analyzing the co-deformation between the external pre-stressed tendons and concrete beams, though section internal force balance equation and deformation of coordinating relations, author make a analysis for a entire process of external pre-stressed concrete beams being loaded from the beginning to undermine with the numerical calculation method. Another, author use the BP neural network to forecast the limit stress of the external pre-stressed tendons.Finally. From the view of numerical simulation, using ANSYS which is one kind of FEM software, the mechanism of action of external pre-stressed tendon is discussed by the analysis of stress,strain,deflection and so on which is fore-and after of concrete simply supported beam of external pre-stressed of reinforcement; and analyze the reinforcement effect of external pre-stressed reinforcement according to reinforce a continuous rigid frame bride.