Carbon Fiber Reinforced Non-linear Finite Element Analysis Of Reinforced Concrete Beams

At first, this paper summarizes recent efforts in finite element analysis of reinforced concrete structures in the world. The constitutive models of steel and concrete are carefully said, which are basic materials of reinforced concrete.And on the base of theory of non-linear finite element analysis, the paper designed a program, which can be used to analyze CFRP strengthened reinforced concrete beams. The program has some main traits:1. It used four elements: concrete triangle element, steel linear element, CFRP linear element, double-spring element;2. It can simulate the phenomena of distribution stress again when the concrete element ripped or the steel bent;3. It simulates the effect of main crack to limit flexural loading;4. It takes into account of friction among ripped concrete elements;5. It used several kinds of methods to distribute the imbalance node loading, and contrast them;6. By changing some parameter of program, it can calculate other strengthening method;7. The compatibility of program is better, and it can be used on all kinds of computers;8. The exploitation of program is so good that it can be designed more and a software system can come into being on base of it.Considering there are not many programs about CFRP strengthened beams in the world so far, on the basis of the program the paper also did the following work:1. The program results is contrasted with experimental results, and the compatibility is well, which proves that the program designed by author is accurate and reliable enough;2. The paper discussed the problem that how to distribute the imbalance node loading to steel and CFRP When concrete element is ripped, and put forward the formula of distribution proportion;3. According to the formula of space between main cracks, the paperdiscussed the achievement method in program;4. The paper found that because of friction among ripped concrete elements, 15%-20% of imbalance node loading must be moved to the structure;5. The paper calculated two series of CFRP strengthened reinforced concrete beams. One is the effect of thickness CFRP to limit flexural loading; the other is the effect of concrete grade to limit flexural loading. The paper also put forward some reasonable advice by calculation.Additionally, this paper also presents a way and direction for the further study on this problem in future.