Study Of The Mechanism Of Roll Straightening With Tension For Medium Plate Based On Curvature Integration

As the development of national economic and industry, the demand of plate of highquality becomes larger and larger. There will be mid-wave and edge-wave because ofthe uneven distribution of temperature and residual stress in the strip, and water mistcooling will cause the buckling to drop the straightness and the shape accuracy of thestrip. In order to get high quality, the strip with defects needs to be fixed andstraightened on a roller straightening machine. At present, the inland research is farbehind the international advanced level; the model of traditional method is too rough todetermine the technology and is difficult to calculate the reduction accurately. Also,there is little research about the roller straightening machine with tension on the twosides of machine. Therefore, it has the important meaning in improving the corecompetence of company to do further research and study of the tension-levelingmechanism.This thesis studied the principle of straightening process based on metalelastic-plastic theory and numerical analysis method. The main contributions of thethesis are as follows.①Compared three straightening methods for roller leveler and analyzed the effectof large deformation, small deformation and linear global reduction method to thequality of strip. The theory of bending straightening also has been researched.②Determined the structure of rollers and number of rollers. Then, According tothe condition of incoming strips, structural parameters such as the roller space, rollerdiameter and so on have been determined by considering the limit of contacting andtorsional strength.③Establish the mathematical model of curvature integral method, and solve theequations to get the technological parameters and energetic parameters by using theoptimization method in MATLAB. Compare the straightening force calculated byanalytical method and finite element software MSC. Marc.④Based on the curvature integral method, analyze the effects of different originalcurvature, reduction and tension stress to the distribution of curvature and residual stressin the strip.This thesis studied the intrinsic principle of straightening of medium plate withtension on the two sides by curvature integral method and analyzed the important parameters which affect the curvature and residual stress. The achievement of this thesiscould provide certain reference value for designing the roller leveler and bettertechnology.