Research On Key Technology Of Roll Forming Of Inner Connecting Corrugated Plate

There are many types of cold-formed steels,which are applicable to a wide range of parts,and can produce parts with relatively complicated cross-sectional shapes.Under the same external load,the weight of cold-formed steel is lighter than that of conventional steel.Cold forming is a high-efficiency,material-saving,energy-saving and environmentally friendly sheet metal forming technology.The inner connecting steel corrugated board culvert has the advantages of high strength,convenient installation and low cost.It has low requirements on foundation bearing capacity and flatness,has strong ductility,and shows good adaptability to terrains such as permafrost,soft soil and expansive soil.In general,the overall cost of steel corrugated culverts of the same diameter can be saved by 40% compared with traditional culverts,and the installation period can be saved by more than 30%.In this paper,the inner corrugated plate is taken as the research object,and the reasonable roll hole shape is designed according to the design principle of the wide corrugated plate.The forming process was rationally simplified and the analytical model was established.The ABAQUS was used to simulate the sheet forming process.The main research contents of the thesis are as follows:(1)The stress and strain states of each pass of sheet metal forming,the transverse plastic strain and longitudinal plastic strain history curve of typical joints and the stress distribution of the transition zone are studied.(2)The effects of different parameters on the forming were studied.The increase in the pitch of the frame and the difference in the roll diameter makes the sheet forming more complete,and the forming speed increasing,and the strain per plate increases,which is not conducive to forming.The influence of friction coefficient on the forming is complicated.The frictional force increases the force of the roll and the sheet material and is difficult to transfer to other areas of the sheet,and it causes uneven distribution of stress and strain in the corner and its vicinity,but also increases the strain value at the corner,thus reducing the springback.(3)The simulation analysis of the on-line three-roller roll bending process was carried out,and the stress-strain distribution of the key nodes was obtained.The causes of the online roll bending rebound were analyzed.By modifying the on-line roll radius of the roll several times,the working radius size value within the required range after molding is obtained,and it provides practical guidance for production.(4)According to the results of simulation analysis,the process parameters were optimized,and a fully automatic cold-bending production line integrating unwinding,feeding,punching,cold-bending forming,in-line bending,length cutting and automatic gathering was built.The corrugated board was connected to the process experiment to realize the mass production of the products.