Research On Deformation Coordination Of Multi-point Flexible Supporting Thick Plate

With the approach of "Industry 4.0",China aims to improve the intelligence level of the manufacturing industry,establish smart factories,and efficiently produce sophisticated products.The steel industry actively takes the supply side as the starting point for reforms and uses the downstream market demand to force the technological transformation of production equipment.Therefore,the straightener,which is the main finishing equipment in steel plate production,has become the focus of reform.Wide and thick plates are becoming more and more stringent due to their extensive application.Production factors have caused the phenomenon of warping to become the primary reason for the quality of wide and thick plates.Steel plates with a thickness greater than 40 mm and excessive warping in the width direction can only be flattened.The traditional flattening machine is expensive and the shape measurement is mainly manual.The setting of the reduction amount and the placement of the horns are based on the experience of the workers.Multiple straightening results in a low straightening rate,which greatly affects the production efficiency of wide and thick plates.In order to improve the leveling efficiency and accuracy and reduce the cost of equipment at the same time,it is urgent to carry out in-depth research on the automation improvement of the leveler and the coordination of the reduction and deformation of the flattening process for wide and thick plates.This topic mainly focuses on the calculation methods of the multi-point straightening and bending amount of wide and thick plates,the selection of the fulcrum distance and the design of the straightening platform,the non-contact online detection of the shape and visualization of the steel plate,and the flattening strategy.First,based on the theory of elastoplastic deformation,a four-point straightening model with small empty straightening area,high straightening accuracy and uniform stress distribution is proposed for the deficiency of the three-point straightening model.The calculation formula of the four-point straightening reverse bending amount is obtained through the curvature integral,the deflection curve equation and the elastic-plastic deformation theory.Secondly,based on the analysis of the straightening results of the two models based on the finite element method,it is concluded that the four-point straightening model has significant advantages in terms of residual deflection and straightening accuracy.The straightening accuracy can be improved by more than 23.3%.Considering the residual deflection of the steel plate,it is concluded that when the fulcrum distance is 1800 mm,the number of hydraulic cylinders can be reduced while meeting the accuracy requirements.A new layout method with staggered distribution of upper and lower flexible supports is designed for the straightening platform.Then,the control variable method is used to analyze the multi-point straightening model with different parameters through simulation,and the error fitting model is established based on MATLAB and the formula is revised in conjunction with the flexible support distribution method.The correctness of the simulation model and the correction formula are verified through experiments.According to the structure of the flattening machine,a laser detection device for the unevenness of wide and thick plates is designed to realize the dynamic detection of the plate shape.Finally,analyze the influence of the non-straightening area and eccentric load on the shape and stress of the flattening process and propose corresponding optimization measures.Combined with the actual situation,the finite element software ABAQUS was used to discuss the flattening strategies of three different types of scooped steel plates: bending along the width of the plate,bending along the length of the plate,and bidirectional bending.The simulation results met the expected requirements.The formulation of a reasonable flattening machine work flow is of great significance to the research of the multi-point straightening process for wide and thick plates.