Simulation And Process Optimization Of The Circular Shear

The emphases of modern steel industry is the improvement of quality. High precisiontrimming circular shears, the important guarantee of plate quality, is widely used in theproduction of the plates and strips. The trimming circular shears of Nanjing Iron&Steelcould only cut25mm or less of steel plate due to its structural defect. In the process ofshear, the defects such as folded edge, high burr, fish-scale bifida and secondary shearsection of steel plate are commonly appeared, which not only affect the shear sectionquality and normal production process but also reduce the life of the shear. Therefore, ithas great significance in the researching of shearing parameters for product quality.This present is focus on the trimming circular shears of Nanjing Iron&Steel MediumPlate Plant. The stress-strain conditions and shearing parameters of the trimming circularshears were studied by theoretical analyses, finite element numerical simulation and fieldtest. The model of cutting-edge steel plate shear has been established by FEA softwareANSYS/LS-DYNA, and the shearing fracture process was simulated. The stress-strainconditions of plates and the change of shear force and lateral force in the shearing processwere obtained. And the effect of the parameters including overlap, lateral gap, and cuttingspeeds on shearing was analyzed. The cause of defects under different kinds of steel andthickness conditions was analysis by sampling deficient steel plate on-site. According tothe results, the optimized shearing parameters and improvement measures have beenobtained.Finite element simulation results show that the steel bite shear force and lateral forcereaches maximum during biting. Different types of steel has various best shearing gap,such as Q235steel is5%of shear plate thickness and Q345steel is6.25%of the platethickness. The shear force reduced effectively with the increment of overlap. In this paper,the shear force could reduce32%maximum and the minimum lateral force is occurredunder-4.5mm overlap. Shearing speed has little effect on shear force. The shear force andlateral force are increased less than8%with shear speed raised from0.2m/s to0.8m/s.The theoretical study and field test results show that that the shear defect appearsmainly due to the illogical shearing parameters, which is the minor overlap or oversizedlateral gap. The parameters of shearing process of Q235and Q345plate is optimized forthe causes of defects, which including the increment of overlap value by1mm, and thesetting of lateral gap as5%and6.25%of the thickness for Q235steel plate and Q345steelplate respectively. The problem of shear capacity and shear defects are solved through thecontrolling of cutting process.