Research On Cold Bending Process Of CAP1400 Surge Line Piping

Based on the AP1000 nuclear power technology, the CAP1400 nuclear power technology, as the third Chinese nuclear power technology, is researched and developed through re-innovating. The Surge Line Piping is the main part of nuclear reactor, so the bending process of the Surge Line Piping is connected with the safe in operation of CAP1400 nuclear and the spread and application of the CAP1400 technology. So the research on the basic theory and FEM simulation are important to instruct the bending process in scene.This article aims at the theory analysis and FEM simulation of the process.Firstly, this article does the theory analysis of the process and establishes the formulas of the minimum and maximum thickness, the spring back angle and cold bending moment, provides the standards in evaluating the forming equality.Secondly, based on the bending process, the article establishes the FEM simulation model in the help of MSC.MARC. The result’s comparision between FEM simulation and theorical calculation confirms the model’s right and concludes that the final quality of bending pipe by origional process can not satisfy the productions’ requirements.Further, aimming at the disadvantages, the article provides two optimizing programmes: the wall thickness’ s designing and bending moudle designing. The wall thickness’ s desiging programme, based on the wall thickness and uses reversable deformation theory, solves the high wall thickness variable rate. Based on keeping the bending raduis, the bending moudle designing programme solves the necking, the worse ovality and constrated stress by adding auxiliary press moudle. The programme also gets the effect law that press moudle distance, turning angle and speed to the final production quality.A parametric design and simulation system for the cold bending of surge bending pipe is developed by combining with the secondary development technology of MARC in the Visual Basic programming platform. The system can accomplish the independent theory analysis of variable Surge Line Piping s,establish and calculate the FEM model and analyse the FEM simulation results. The system has very good actual using value which can effectively shorten the new product development cycle.