A novelty mandrel supported thin-wall tube bending cross-section quality analysis: a diameter-adjustable multi-point contact mandrel

The mandrel plays a vital role in metal tube bending limit improvement and high-quality achievement. For the forming process of tubes with different diameters, corresponding needs to be customized, which has disadvantages long design cycle, high manufacturing cost, low reuse rate. Therefore, novelty concept diameter adjustable (DAM) based on multi-point contact was proposed adapt processes. Since point-contact characteristics DAM can lead irregular cross-section deformation, cross-sectional full profile radial error (FP-RE) model proposed. As more comprehensive evaluation model, FP-RE is used measure deformation degree whole cross-section. A diameter-adjustable adopted AISI 304L (the inner = 40–56 mm) experiments. maximum absolute 0.11% compared ones obtained from FEA Abaqus/explicit. In addition, effects characteristic parameters, viz., support blocks amount, effective magnification, diameter, quality were discussed. results indicated that (a) an even number could prevent collapse outer convex wall improve concave wall. (b) When larger bending, non-contact area would cause increase roundness section distortion. (c) minor for same while thinning just opposite. Finally, result also proved minimum 40 mm six blocks) about mm, acceptable.