Study On Shear Force Of Wide And Thick Plate Rotary Trimming Shears

The rotary trimming shears is used for trimming of wide and thick plates in the finishing line of steel rolling.With the continuous improvement of the finishing process and technology level of the plate,the rotary trimming shears is developing in the direction of thicker shear plate,larger blade diameter,higher shear efficiency and shear quality.The calculation of shear energy parameters of edge-cutting disc is the key to its structural design and shear process parameter setting.At present,the calculation formula of shear force of disc is mostly introduced by empirical formula or other shear force formula,which does not consider the actual shear force characteristics in depth and can not calculate the shear force of wide and thick plate well.Based on the actual working conditions of the trimmed disc shears,the theoretical analysis of the plate biting process is carried out,and the value range of the plate biting angle is obtained.The mechanical analysis of the stable shear process is carried out,and the stress characteristics of the stable shear are obtained.The theoretical formulas of shear angle and shear area are re-established,and it is clear that the shear force direction of the shear process should be parallel to the direction of the upper and lower shear blade axis connection.The shear force in the stable shear stage is divided into four parts : plastic shear force,crack propagation force,trimming bending force and lateral contact friction force,and the shear force calculation formula suitable for rotary trimming shears is re-established.By introducing the model and related experimental data,the specific expression of the shear force related influence coefficient is obtained by fitting,which effectively reduces the theoretical calculation error.Comparing the calculated value of the shear force formula with the measured value and the ABAQUS numerical simulation results,it is concluded that the established shear force calculation formula is reliable.The influence of process factors such as shear speed,plate thickness,shear blade diameter and cutting edge on shear force was analyzed by ABAQUS numerical simulation,and the reliability of shear force calculation formula was further verified.Based on the established shear force calculation formula,the shear torque and shear power of different plate thicknesses are calculated theoretically,and the theoretical reference values of shear torque and shear power of disc shear are obtained.Through theoretical analysis and numerical simulation,the mechanical characteristics of the shear process of the wide and thick plate rotary trimming shears are studied,and the shear force calculation formula suitable for the rotary trimming shears is re-established.The formula takes into account the specific effects of multiple process factors,which will provide some theoretical support for the design of the disc shear and the further improvement of the shear capacity.