Finite Element Simulation And Section Quality Optimization Of New Zirconium Alloy Sheet Blanking

Zirconium alloy is widely used in nuclear power and aviation because of its excellent corrosion resistance,mechanical properties and low thermal neutron absorption cross section.In the field of nuclear power,the stamping process is mainly used to process the zirconium alloy sheet.The quality of the characteristic section after blanking affects the forming quality of the strip and the assembly quality of the grid.Therefore,it is very necessary to study the quality of the blanking surface of the zirconium alloy sheet.Of zirconium alloy sheet metal cutting processing,sheet metal deformation area are mainly concentrated in extremely narrow blanking clearance,die deformation time is short,the deformation process with geometric nonlinearity,material nonlinearity and contact nonlinear characteristics,the coupling relationship between different processing parameters must be taken into consideration at the same time,thus further analysis of zirconium alloy sheet metal blanking section quality also is particularly complicated.Is widely used in recent years,the finite element analysis technology,using the finite element analysis software to sheet metal blanking process simulation analysis in the section of the parts prior to actual production quality has plenty of understanding,solving problems that may occur to effectively improve the quality of parts of the cross-section,decrease the mould wear,prolonging the service life of mould,provides some reference guide for practical production.In this paper,the domestic new type of zirconium alloy sheet metal as the object of analysis and research,using DEFORM simulation analysis software to blanking the whole process of the new type of zirconium alloy sheet metal finite element simulation analysis.A single factor blanking simulation model was established to analyze the variation rule between blanking process parameters and the length of bright zone of blanking groove section.The response surface method was used to design the simulation test scheme and analyze the interaction between the factors.The punching sequence die was designed to verify part of the simulation test data by physical test.Ga-bp neural network model was established to predict the length of bright zone,and genetic algorithm was used to optimize it.The thesis mainly includes the following contents:(1)The material parameters required by the finite element simulation model are obtained through experiments.The anisotropy of zirconium alloy is obvious,and the anisotropy material model needs to be established during the finite element simulation.The material parameters for this model include Young’s modulus,Poisson’s ratio,K value,N value and three direction anisotropy coefficient.In this paper,the above parameters are measured and calculated by three-direction tensile test.(2)Using DEFORM blanking model simulation of new zirconium alloy plate blanking deformation process,analyzes the blanking deformation in the process of stress and strain state,and uses the single factor analysis method,research the different influence factors(friction coefficient,the blanking clearance,cutting speed and mould cutting edge radius)hedge cutting surface brightness the influence law of belt length.(3)The response surface method was used to design the simulation test of a new type of zirconium alloy thin sheet,and the mathematical function expression between the influencing factors and the length of the bright band on the cutting surface was established.The interaction between the influencing factors and the length of the bright band on the cutting surface was studied according to the simulation test results.The simulation scheme of partial blanking was tested and verified by designing the sequential die.The average absolute value error between the test data and the finite element simulation data was 2.81%,and the data results showed that the finite element simulation model was reliable.(4)Use of stamping simulation test data and the physical experimental data set up the 3-11-1 three layer GA-BP neural network prediction model,using the genetic algorithm based on neural network prediction model optimization,optimal process parameters,the results show that the process parameters before optimizing blanking physical test biggest euphotic zone length ratio increased by 12.36% on average.The feasibility of applying the finite element simulation and GA-BP-GA neural network model to predicting and optimizing the length of bright strip on the cutting surface of new zirconium alloy was verified.