Research On Warm Bending Forming And Process Optimization Of CAP1400 Wave Tube

Wave tube is an important pipeline equipment for pressurized water reactor nuclear power plants.It connects the main pipeline and voltage stabilizer.It is a nuclear safety firstclass pipeline.The CAP1400 nuclear power surge tube is assembled from five sections.Among them,the bending angle of section 002 pipeline reaches 180°,and the bending angle is the largest.It is prone to defects such as excessive ellipse,excessive thinning of the outer wall thickness and even breakage.Compared with the cold bending process,the warm bending process has good plasticity,low resistance and return.Compared with the hot bending process,the advantages of elasticity and easy control,such as excessive oxidation and strength deterioration,will not occur.Therefore,the research on the warm bending forming of section 002 of CAP1400 wave tube has certain guiding significance.The main research content of this article is mainly divided into the following aspects:First,the theoretical analysis of the forming process of the wave tube is carried out,and the theoretical analytical formulas of the minimum wall thickness,the maximum wall thickness and the rebound angle of the final state of the wave tube are obtained.Aiming at the original bending process parameters of section 002 of the wave tube,based on the MSC.Marc platform,a simulation numerical model of the whole process of warm bending forming of section 002 of the wave tube is established to predict the forming quality of the product.The simulation results are in good agreement with the theoretical results.Secondly,through orthogonal experimental design,numerical simulation is used to obtain the maximum thickening rate,maximum thinning rate,ovality and damage value of the wave tube under different process conditions corresponding to the orthogonal design scheme,and the respective values are obtained through stepwise regression analysis.The influence of bending process parameters on the forming result.Thirdly,based on the BP neural network,the wave tube forming quality prediction model is established,and the nonlinear relationship between the bending process parameters and the maximum thinning rate,ovality and damage value is established;the genetic algorithm is used to optimize the process parameters to complete the optimization process The product quality prediction corresponding to the parameter satisfies the evaluation requirements of each forming index.Finally,using the GUI platform of MATLAB,combined with the BP neural network model and the genetic algorithm optimization model,a human-computer interaction system for predicting the results of warm bending forming of section 002 of the CAP1400 fluctuating tube and optimizing process parameters is established.