Springback Analytic And Process Parameters Optimization Of Plate Edge Preflex For The Forming Of Large Diameter Longitudinal Seam Welded Pipe

With the more energy consumption such as global oil and natural gas, pipelineconstruction has been developed rapidly and the demand of large-diameterstraight-welded welded pipe (LSAW) is increasing. JCO forming, as the firstproduction technique for LSAW, On the bending forming quality control and processparameters adjustment can only rely on the experience of the staff, there exist processparameters adjustment error and product quality fluctuation of the problems of theneed to perplex process of the system, establishing a reasonable to the bending ofprocess parameters.Firstly, according to forming characteristics of large-diameter longitudinalwelded pipe, based on theory of plastic bending, the reasonable assumptions wasconsidered and the forming model was simplified in the paper. According to geometricrelations between pre-bending moulds and slab, the spacing from upper die to lowerdie, radius of curvature at any angle of pre-bending slab were deduced. At the sametime the index sclerosis and bilinear sclerosis two material model, this paper derivedafter spring back perplex bend Angle and the process parameters of between analytical,and termination of perplex moment analytical forming force.Then，using ABAQUS finite element analysis software, X70 pipeline steel and 20# steel as the main research object, established the finite element simulation model ofbending forming, through the discussion finite element algorithm, different elementstype on the bending forming and the influence of the simulation calculation precisionspring back, determined the advance of bending forming for finite element numericalsimulation parameters. This article introduces bending forming stress and straindistribution characteristics, discusses the material properties, friction coefficient, sheetthickness and perplex length factors on the rebound after the influence law of bendAngle.Then, used X70-Φ1067×19.1×12000 mm straight tube welding seam perplexprocess as an example, the finite element simulation model, through the actual production data to validate the theoretical derivation and simulation model is correct.And also used perplex length as design variables, established the process parametersoptimization model, and in the process of welded tube production perplex processparameters selection provides important theoretical basis, has theoretical significanceand practical application value.