Research On Springback And Accurate Cutting Length Of Tube Bending

A 10,000 tonnage vessel may apply approximately 10,000 meter-long tube.And the processing amount of tube bending accounts for about 60% in total tube processing. Processing quality and efficiency of tube has a great impact on the shipbuilding cycle. Study of springback and precise cutting plays an important role in improving the quality of tube, reducing material waste, developing process of welding first then bending, improving production efficiency of tube and even shorting the entire ship production cycle. The main contents are as follows:Theory research of springback: analyzed elastic and plastic regional changes on cross section of tube according to pure bending model, neglected the moment of elastic deformation region Me, and power-law hardening model was used to describe the relationship between stress and strain on whole cross section,established approximate formula of springback angle and radius of curvature after springback with the consideration of wall thickness. Analyzed the effects of mechanical properties of materials, size of tube and bending size on springback.Finite element analysis of springback: technological parameters of mold have a great influence on springback of tube, and it is hard to study by theoretical calculation. Designed orthogonal experiments, built thin-walled tube NC bending models of different process parameters rely on finite element software DYNAFORM, simulated the process of forming and springback of tube, range analysis and variance analysis were used to analyze the angles of springback.Analyzed the effect of various factors on springback, and came up with optimization schemes to reducing springback of tube.Research on precise cutting length of tube: analyzed the stress on cross section of tube bending, deduced the formula of radius on strain neutral layer,established precise cutting length formula of variation bending with the consideration of wall thickness.