Numerical Simulation And Experimental Study On Section Steel Straightening Mechanism

Steel sections play more and more important roles in every aspects of national economy. With the demand of high quality product, the undesired bending defects often occurred during the manufacture process of steel sections must be corrected. This thesis systematically addresses the fundemental theories involved in the straighting process of steel section products. These include the stress-strain relationships, the cuvature changes, the equation of moments, and the energy consumption, etc. The fundermental theory of 3D elasto-plastic finite element analysis (FEA) is also discussed.The explicit FEA software ANSYS/LS-DYNA has been used to perform the simulation of the elastic-plastic strainhtening processes. For the straighten- ing process of 30 kg/m rail using uneven-spaced straightening roller configura- tions, the stress and strain histories, the energy consumption, and residual cuvature during the bending correction process have been analysed. The characteristics of variations of stress and strain with time at critical points are also interpreted. The straightening processes of 36U and 11# steel sections used in the mines using 800 mm equal spaced straightening roller configurations have also been simulated. The analyses of this process are concentrated on deriving the straighting forces.Finally, the field measuring and the calculation of the amount of reduction for different types of straightners are desribed. The motor voltage and electric current values were measured for both idle running and work loading states. The differences of these values can be used to figure out the straightening forces. By comparing the FEA results with the experimental test results, a correction method for straightening force has been proposed, which can be used as a good guide for real life production processes.