EXPANDED TUBE EVALUATION METHOD, EXPANDED TUBE EVALUATION METAL MOLD AND EXPANDED TUBE EVALUATION TUBE

摘要

To easily evaluate an expanded tube having a defect by using an evaluation tube.SOLUTION: An evaluation method of an expanded tube acquires the distortion history of a full-scale expanded tube from a numerical analysis or an experiment of the expanded tube, derives a stroke of a core grid in which the peripheral distortion of an evaluation part of an evaluation tube is similar to that of the full-scale expanded tube, and the axial distortion of the evaluation part is accommodated within a range of the full-scale expanded tube axial distortion ± 1.5% when using the core grid for pushing out a split mold arranged in the evaluation tube having an artificial defect to a radial direction of the evaluation tube, forms the expanded evaluation tube by pushing out the split mold by moving the core grid within a range of the derived stroke, and determines the adaptability of the full-scale expanded tube corresponding to the evaluation tube by confirming a state around the artificial defect of the expanded evaluation tube.SELECTED DRAWING: Figure 7