The Effect of Polyurethane Mandrels and NBR in the Bending Process of Steel Pipe with using the Numerical Simulation and Experimental Test

Today, the bent tubes of various bending radius are widely used in the automobile, aerospace, and shipbuilding industries. In the tubes bending, the smaller the bending radius and wall thickness of the tube, the greater the likelihood of defects such as wrinkle, rupture and non-circularity of the cross-section of the tube. Therefore, one of the most important issues is how to fix these defects. For the reduction of wrinkle and rupture, the effect of geometric parameters of bending tools, mold and mandrels in pipes are been considerate. The type of mandrel used in the bending process can be effective in optimizing bending mold force and the reduction of wrinkle and rupture. In the paper, the simulation and test of the rotational tube bending process will be presented with using elastomer mandrels of polyurethane elastomeric mandrels and NBR and then the crucial mechanical and physical properties for steel tubes of different diameters. Then the optimal parameters are determined for bending the tube without rupture with using mold force, internal and kinetic energy. The test results verify the simulation results.