CURLING OF THIN TUBES - ANALYTICAL AND EXPERIMENTAL-STUDY

The curling of thin tubes under compressive loads produces double wall ed tubes for many engineering applications. Experiments have been perf ormed on annealed copper, low carbon steel, stainless steel, and alumi num tubes to determine the relationship between the curling process pa rameters and the tube geometry, as well as tube material properties. E ffects of friction and work hardening during forming are included in t he analysis. The analytical and experimental results are compared with published results to determine the validity of the proposed analytica l model. The model can be used to determine the curling load and the c orrect die radius for successful curling. For simple and quick determi nation of the die radius, the present work introduces design curves, w hich correlate the tube geometry with the radius of the forming die.