This thesis has investigated the best method for bending large diameter pipes with relatively small bend radii. This method is called Induction Bending. In order to get the benefits of this method, a comparison with the other methods for pipe bending is presented and it was realized that this method is the best one for bending large diameter pipes with small bending radius. To evaluate this method, an elasto-plastic coupled thermo-mechanical model was built to simulate induction bending of large diameter pipes. Local induction heating, bending large diameter tubes with small bending radii and rapid cooling of the tubes after bending process were considered in these simulations using ABAQUS software. Mechanism of metal deformation during the bending process was studied in detail. Influencing parameters, such as thinning and thickening of the tube wall thickness, ovality of the cross-section of the tube, spring back angle after unloading and required push force were obtained. These influencing parameters were compared, with and without the presence of a reverse moment acting to the bending arm. It was realized that an appropriate reverse moment should be applied to the bending arm to keep the wall thinning within a required and acceptable value. In this investigation a simple analytical solution is also presented to predict forming conditions such as strains, stresses, tube geometry, forces and moments. The results are also compared with FEM simulations, obtained by ABAQUS software and with available experimental data. The results of analytical and FEM simulations are very well in agreement with experimental observations. It was concluded that for a quick evaluation of the process, the proposed analytical solution is quite satisfactory. Since the pipe after passing induction coils is cooled rapidly then the granular structure of the pipe changes. To know more about one a computer simulation has been done on the pipe by AC3 software.
