Parameters Optimized Design, Simulated And Experimental Study Of Unequal Roller Spacing Straightening Machine

As a kind of finishing technology, straightening is more and more significant and have been a dispensable branch of industrial development. Unequal roller spacing straightening is an advanced straightening technology, it combines characteristics of equal roller spacing and variable roller spacing technology: it has high straightening precision, it can straighten wide specifications and kinds of rolled piece, it manipulates simply, its application is promising. That's why it is necessary for unequal roller spacing straightening machine to study on theory and apply in practice.Precise theoretical analysis of straightening is the basis of production control in practice. According to straightening theory, analyzed the force and deformation of steel bars in the course of straightening and mastered the process of steel bars straightened gradually by unequal roller spacing straightening machine. According to the elastic-plastic flexure theory, studied stress, strain, bending moment and springback of any little part of steel bars at arbitrary direction in the course of straightening and found the relationship between original curvature ratio, inflection curvature ratio and them, which could be a theoretical foundation for following design and calculation of parameters and simulation study.According to characteristics of unequal roller spacing straightening technology, established straightening scheme. According to contact stress and nipping condition, calculated the range of each structure parameter, then taking the sum of straightening force as objective function, optimized roller spacing by fmincon in MATLAB. This way can not only make machine in a good condition and have good straightening qualities, but also provide valuable references for design and research of unequal roller spacing straightening machine. Then got each structure parameter and theoretical values of straightening force. Meanwhile, established the relationship between curvature ratio and bending deflection, calculated rolling reduction of each rollers under different original curvature ratio and diameters of steel bars and found the matching relationship between them and the regulations of change. This way can make giving rolling reduction more easily, also make straightening efficiency and precision higher. Through studying straightening parameters, found rational parameters in the course of straightening steel bars of different diameters so that guaranteed straightening qualities, which provided scientific basis for formulating, optimizing of parameters as well as craft.According to optimized roller spacing, roller diameter, roller length and corresponding rolling reduction, established straightening system model by ANSYS/LS-DYNA and simulated, then examined straightening force, straightness as well as residual stress of ?8??10??12mm steel bars, in order to verify the effect of optimized design, rationality of simulation model and method as well as straightening qualities of unequal roller spacing straightening machine. Then compared the straightening qualities with equal roller spacing straightening machine, it demonstrated the superiority of unequal roller spacing straightening machine. Mastering this simulation technology helps to improve production efficiency, also reduce costs of straightening, which provided a new study approach for mastering deformation mechanism, improving and developing straightening theory. Then through analyzing and calculating experimental data of ?8??10mm steel bars straightened by unequal roller spacing straightening machine, and compared the experimental data with equal roller spacing straightening machine, it proved the straightening qualities of unequal roller spacing straightening machine is better as well, which plays a vital role in practice and popularization of study method. At the same time, simulating and experimental study reflected the advantages and disadvantages of unequal roller spacing and equal roller spacing straightening machine, it is good to take advantages of them in operation, generalize better equipments as well.The analytical method combined theory, simulation and experiment in this paper is a good try for the study of straightening technology in future. It has theoretical and practical significance.