Tube bending on the roll machine

Thin-walled tube plastic crash in bending

“…In the case of Bernully-Euler kinematics hypothesis, which is valid for a long bending arm L, elastic stage is constrained by the curvature 1 and moment M 1 defined by Equations [7] …”

“…In the case of tube bending without inner filler or mandrel critical curvature * is constrained by circular section distortion, which defined by Prager's plastic hinge mechanism, induced by inner equilibrium compression forces [6,7] (1-/E) [(½ -* ) sin * -cos * )] = 1 sin 1…”

“…Relevant non-linear bending problems of strip and sheet on the roll machines are given in [3,4,5]. Simulation of the tube push bending on the roll machine with limit curvature estimations is considered in [6,7].…”

“…1. Tube bending analysis is based on Bernoulli-Eulero hypothesis for long beams, using numerical non-linear procedures [6,7]. Initial linear tube on the circular supports with radii r 0 is bended by the central circular toll with radius R 0 .…”