Study On Roll Shape And Accuracy Of Non-uniform Slende Axle Parts Straightening

With the development of mechanical industrial and national economic, therequirements of the variable cross-section slender shaft products’ quantity and quality aregetting higher and higher in the fields of industrial production and infrastructure, etc. Butbecause of the stiffness difference, stress concentration and some other reasons, thecross-section slender shaft usually get ellipse, bending and other defects in the process ofthe fabrication. So it must be straightened before being used. If we want to betterstraighten special section, we must not only consult all kinds of straightening theories andexperiences from domestic and foreign about steel, but also consider the particularity ofthe components external dimensions. Now, the research about this kind of straightening isso little. So it is the problem which needs to be resolved urgently in the study ofstraightening technology theory.In this paper, according to the elastic-plastic bending theory, the straightenedproducts were analyzed on the stress and deformation in straightening process andcombining the special external dimensions, we choose a kind of reasonable straighteningprocesses, namely three-roller straightening. The distribution of three rollers in space is120°, and the rollers will be changed because of the different products. Among the threerollers, two are driven rollers and the other one is responsible for press. Compared withother straightening process, the biggest superiority of this kind of straightening craft is thatit is more efficient to straighten some small multi-tapered shaft and the level can meet thenational requirements.This paper is primarily based on MARC, Solidworks and Abaqus to carry out thestraightening model and the multi-group finite element simulation firstly. By comparingand analysis the results of simulation, we can study the deformation rule more in-depth intheory. It can make up for the deficiency of the experimental data and can reduce a lot ofmanpower and money.By consulting massive correlation literature, we work out the relationship betweenbending deflection and curvature, bending moment, energy consumption when thework-hardening effect is under consideration. We make sure the feasibility of the straightening method and put forward three-roller straightening precision theoreticalcalculation formulae. We establish three dimension finite element model of straighteningafter calculating and optimizing the related straightening parameters with the help of theMATLAB genetic algorithm toolbox, including the roll radius, the roll length, the radiusof roll curvature as well as straightening speed and so on.Based on the finite element analysis software, we conduct some numerical simulation.We analyze the result of the simulation, mainly analyze the variation of the stress field;analyze the distribution of the residual stress after the straightening; study the variationrule of the stress and displacement at the special point in the hole straightening process.We also find out the influences of different parameters on straightening accuracy. It has animportant practical significance to further improve the straightening accuracy of thevariable cross-section slender shaft and also can provide a kind of reliable theoreticalguidance for practical production.