Research On Key Technology Of Roll Forming Of Piece-packed Corrugated Plate

The roll forming process belongs to the elastic-plastic large deformation problem.In this paper,it includes two processes: cold forming and online three-roll bending forming.There are nonlinear problems of material,geometry and boundary conditions in the forming process,so the design and simulation of roll forming process is very difficult.At present,the deformation law and characteristics of sheet metal in cold bending process have not been fully mastered,which is called “unmastered art”.The cold bending process and roll pass design in actual production mainly depend on the designer ' s experience.In this context,this paper takes the roll bending forming of corrugated plate as an example,uses the special design and analysis software COPRA for cold bending forming to design the roll pass,and designs the roll pattern and roll diagram of the product.The forming process is simplified,and the finite element model is established.The finite element simulation analysis of the cold bending forming and online three-roll bending forming process is carried out.The research contents and conclusions are as follows:1.Roller pass design of Piece-packed corrugated plate.According to the basic principle of cold bending hole design,combined with the actual production experience,the parameters in the hole design are calculated,and the hole system,blank width,bending method,forming pass number,forming angle and pass spacing are determined.The roll hole design of corrugated plate is completed.Finally,the product roll pattern and roll diagram are given.2.Establishment of finite element model of cold bending.According to the characteristics of roll forming,combined with the structural characteristics of corrugated plate and the actual production experience,the forming process is simplified,and the parameters of the plate mesh,material model,boundary condition,contact and working load are set up.The finite element model of roll forming is established.Through the analysis of stress and strain in the bite process,the feasibility of the bite model is proved.3.Analysis of finite element simulation results of cold bending forming process.This paper analyzes the distribution and variation of stress and strain in the forming process,the stress and strain history curve of the special parts of the sheet,and the influence of process parameters on the forming process of the sheet.The following conclusions are obtained:(1)In the transverse direction of sheet metal,the variation laws of equivalent stress and strain path curve are similar,but the distribution of equivalent stress is complex.The equivalent stress and equivalent strain mainly occur at the bending angle and its adjacent areas.The equivalent stress reaches the maximum in the area near the bending angle,and the equivalent strain reaches the maximum at the bending angle.(2)In the process of sheet metal deformation,the equivalent stress at the corner node increases firstly and then decreases and finally fluctuates in a small range when the plate enters and exits a group of rolls.It can be concluded that the cold bending process is a process of multiple loading and unloading.From the analysis of the strain curve,it can be known that the equivalent strain history curve changes in a ladder-like cycle during the forming process.The sheet deformation is the result of the combined action of transverse deformation and longitudinal deformation,and the transverse deformation is the main form of expression.Therefore,in the design of the forming process,the distribution system of the transverse deformation of the sheet is mainly considered to ensure the shape,size and quality of the product.4.Analysis of finite element simulation results of online three-roll bending process of profile.This paper mainly studies the law of three-roll bending forming,analyzes the distribution and variation of stress field and strain field in the process of profile forming,studies the equivalent stress-strain curve of the key parts of the profile,and finally studies and analyzes the forming process and springback of three-roll bending.It is concluded that the variation of equivalent stress and equivalent path curve is similar,but the distribution of equivalent stress is complex.The stress and strain at the edge of the profile are large,and the plastic tensile deformation occurs.In the profile longitudinal direction,every roll in and out,the bending force(Z direction stress)and equivalent strain have a first increase and then decrease,the strain decreases greatly.So the visible springback is relatively large.5 Experimental study on roll forming process of corrugated plate.According to the analysis of the simulation results,this paper completed the parameter optimization of the forming process.Through the single plate roll bending process test,the product was trial-produced,and the feasibility of the technology was verified.It laid the foundation for the subsequent construction of large corrugated plate continuous forming and online roll bending production line,and played a technical test verification effect.