FEA On Surface Shot Peening To Strengthen Railway Vehicle Bodywork

This topic researched on how to enhance its service life of the chassis steel structure urgently according to our actual demand. It carries on using the computer simulation technology to the chassis steel structure shot peening strengthening process the movement simulation, through shot peening the stress, the strain field which the pill craft caused carries on the value simulation, the utilization limited unit law to the projectile hit rear spring material surface stress, the strain distribution has carried on the value computation and the statistical analysis. I have discussed the relations between the jet speed, spray angle, the projectile diameter, the residual stress and the strain. I choose several groups of typical parameters to compare, in the analysis different situationshot peening to the local distortion influence, then shot peening strengthening craft parameter to the chassis steel structure to carry on the optimized choice. To the optimized parameter which obtains has conducted the experimental study, mainly discussed the jet velocity and the angle to the steel structure surface strengthening effect influence rule.Firstly I have establishedshot peening strengthening finite element model at the jet velocity as 40m/s, 60m/s, 80m/s, 100m/s, the spray angle for 45°, 60°, 75°, 90°, the projectile diameter ;0.8mm, 1.0mm,1.2mm,1.6mm,2.0mm, the impact identical goal steel plate single grain of the pill. I have carried on the movement simulation using the finite element software to the establishment each kind of finite element model, had discovered the goal steel plate receives the projectile attacks repeatedly when the stress and the strain change rule: The jet velocity and the projectile diameter counter stress, the strain influence are very big, but spray angle major effect strain.Through to the projectile diameter, the jet velocity, the spray angle craft parameter optimizes, obtains: Regarding the 1mm diameter projectile, the spray angle for 90°, chooses 60～80m/s the speed to be possible to obtain the good comprehensive effect; Regarding the jet velocity is 80m/s, the projectile diameter for 1.0mm, spray angle for 60°appropriate; The jet velocity is 80m/s, the spray angle for 90°, the projectile diameter should take 1.0～1.2mm. To the optimized craft parameter which determined has conducted the experimental study, mainly has analyzed the strengthened steel plate surface macroscopic roughness and hardness changed rule, I found: When other craft parameter same, the projectile speed is bigger, the surface roughness Ra ascension is bigger; The spray angle is bigger, the surface roughness is bigger. The speed is when 60m/s the surface hardness enhances 24.1%. The speed is when 80m/s the surface hardness enhances 38.6%.But when other craft parameter same, spray angle to degree of hardness influence basic consistent, angle for 60°when the surface hardness enhances 24.1%; Angle for 90°when the surface hardness enhances 27.6%. When speed certain, the angle for 60°compared to 90°can improve the steel plate surface quality well. When angle fixed, considered merely the speed to the steel plate surface roughness influence, the 60m/s speed is more appropriate. This conclusion is consistent with the optimized parameter which obtains with the analog computation.On the one hand the experiment explained this topic will use the research technique feasibility, more importantly the result and the method apply in the railroad vehicles manufacturing industry, will be helpful to when will carry on the surface treatment chooses the appropriate craft parameter, thus will improve the chassis steel structure surface quality, will lengthen the vehicles service life.