SIMULATION OF ORBITAL FORMING PROCESS
In this study the feasibility of 3D FEM simulation of the orbital forming process was investigated by evaluating the simulation time. Commercial FEA software DEFORM 3D v4.0 that has an efficient computation algorithm for simulating incremental forming process was used for the simulations and the savings in computation time was determined. In order to provide reliable flow stress for the simulation, a finite element based inverse analysis technique has been introduced. Results show that developed inverse analysis technique is efficient and accurate for use in 3D FEM simulation for process optimization.
Inverse problems in finite element simulation of metal forming processes
Focuses on the inverse problems arising from the simulation of forming processes. Considers two sets of problems: parameter identification and shape optimization. Both are solved using an optimization method for the minimization of a suitable objective function. The convergence and convergence rate of the method depend on the accuracy of the derivatives of this function. The sensitivity analysis is based on a discrete approach, e.g. the differentiation of the discrete problem equations. Describes the method for non‐linear, non‐steady‐state‐forming problems involving contact evolution. First, it is applied to the parameter identification and to the torsion test. It shows good convergence properties and proves to be very efficient for the identification of the material behaviour. Then, it is applied to the tool shape optimization in forging for a two‐step process. A few iterations of the inverse method make it possible to suggest a suitable shape for the preforming tools.
Preform design in ring rolling processes by the three-dimensional finite element method
Abstract Perform design by the three-dimensional finite element method has been carried out for plain ring rolling and T-section profiled ring rolling. The application of the backward tracing scheme for perform design in ring rolling processes demonstrates, for the first time, the extension of the scheme into three dimensions. The preform design in plain ring rolling aims at obtaining a preform which simulates a final plain ring product with uniform axial height. Loading simulations were carried out for two progressively modified preforms derived from the result of loading simulations with a rectangular-shaped ring. Then, backward tracing was applied to obtain a final preform for the specified product configuration of uniform axial height. The preform in the T-section profiled ring rolling process was to be designed to simulate a final profiled ring product with complete filling in the groove and uniform axial height. The final preform shape for plain ring rolling was selected as a trial preform in T-section profiled ring rolling. A more satisfactory preform was obtained from the backward tracing results. It was shown by forward simulation that the final preform was good enough to satisfy the design criteria.