Research Of GH4169 Rolling Blade Fracture Model And Simulation Of Forming Process

As a widely used thin-walled part,the blade plays a vital role in aero engines and gas turbines.Because the curved surface of the blade is complex and it is required to work in the harsh working environment of high temperature and high load,the formed part must have high strength and fatigue performance.In addition to meeting the performance requirements of blade forming parts,the rolling process also has the characteristics of low technical cost and short manufacturing cycle.Therefore,this process is often used to process aviation blades.However,during the roll forming process,due to factors such as the initial structure of the blank,the material’s own properties and process parameters,defects such as cracks will occur in the formed part.Therefore,it is of great significance to study the law of crack generation and the formation mechanism of key areas by means of numerical simulation.In this paper,a kind of non-tenon blade is used as the research object.Based on GH4169 material,the ABAQUS platform is used to simulate the location area of cracks during the blade forming process and the effect of external factors and internal factors on the cracks is studied.At the same time,its influence on the formation of key areas of the blade was studied.This paper first selects a hybrid hardening model with an isotropic strengthening coefficient C as the constitutive model.In order to improve the calculation efficiency,an explicit radial return algorithm was adopted as the VUMAT development method of the hybrid hardening model,and the MMC model was added to the model as a damage criterion.A blade rolling finite element model was established in the ABAQUS platform for analysis.The method of combining simulation and experiment was used to solve the unknown parameters in the MMC model with the least square method.The developed model is used to simulate the notched tensile test of a certain GH4169 material,and the relative error between the simulated displacement load curve and the experiment obtained is within 5%,which proves that the model is correctly developed and suitable for GH4169 material.The method of controlling variables was used to analyze the influence of the external process parameter reduction amount,rolling speed and bite position,and the internal parameter isotropic strengthening coefficient on damage.Among the external process parameters,the most significant effect on the damage is the reduction amount,followed by the rolling speed,and the bite position has almost no effect.When the isotropic strengthening coefficient is increased,the degree of damage is lower when the process parameters are not changed.Based on the analysis of the maximum equivalent stress and equivalent plastic strain in the key damage characteristic area,the ruler of blade roll forming in this area is obtained:the increase of the reduction amount will promote the increase of the equivalent plastic strain and the maximum equivalent stress,and the increasing isotropic strengthening coefficient will have a certain hindrance effect on the metal flow.But the hindering effect of the isotropic strengthening coefficient decreases with the increase of the reduction amount.Increasing the rolling speed will cause the equivalent plastic strain and the maximum equivalent stress to decrease firstly and then increase and the increase of the isotropic strengthening coefficient will have a certain hindrance on the metal flow and the hindrance effect will first increase and then decrease as the rolling speed increases.