An accelerated simulating method for flow forming process through locally and dynamically rigidifying the workpiece

Flow forming is a widely used process for manufacturing tubular parts in the aerospace and defense industries. In this process, the workpiece is produced locally and continuously under the action of the mandrel and feed of roller(s), which requires a lengthy finite element simulation (FES) time. To speed up the FES, dynamic rigidifying the portion of the workpiece which undergoes little or no deformation is an available method to reduce the amount of calculation. The mobile region that deforms plastically during the process can be identified based on the position of the roller(s) and then projected onto the designed workpiece to construct the rigid-flexible coupling model. This identification can be accelerated by clustering the elements of the workpiece into a sequence of blocks along the axial or hoop direction, or both. Thus, the workpiece can be subdivided into blocks or simply into rigid and deformable parts along the intersections of the blocks. In addition, the partitioned workpiece is overlaid by a structured mesh to store the historical data during the process and ensure accuracy. By integrating the above methods, the local and dynamic rigidification method can be applied to simulate the flow forming process via the secondary development of Abaqus. Comparing the precision and efficiency of models divided along diverse directions, the model divided along the axes has the optimal performance and can reduce the calculation time by 1/4 to 1/3. When the workpiece is cut only at the interfaces between rigid and deformable parts, the FES results for the large radius model show that rigidification performs well with large reduction. And the model which has a long workpiece can obtain a better-accelerating performance.