FORGE® for flowforming
FORGE® can address the simulation of flowforming process, dedicated to manufacture parts of revolution. Flowforming is a shaping process based on the plastic deformation of metal, between a mandrel and a roller. It can be carried out cold or hot, and makes it possible to produce parts of revolution without welding, with variable thicknesses while preserving the fibre of the metal.
Since flow forming is an incremental process with many rotations of the part-mandrel assembly, a large number of increments is necessary with a Lagrangian formulation to respect the geometry. In order to reduce the calculation time, it is therefore interesting to use simulation models that approximates the rotation of this process.
Hub spinning stress
FORGE® allows accurate prediction of:
- The geometry of the component in the final stage
- The distribution of the thickness of the part, and the presence of local striction
- Defects, such as the presence of folds
- Metallurgical developments in the case of hot flow forming
- Plastic deformation
- Residual stresses
- The damage criterion of Latham and Cockroft (rupture in tension)
- The optimal speed and displacement cycle of the roller
- The force of the roller
Folds prediction during flow forming
COMPETITIVE FEATURES OF FORGE® FOR FLOW FORMING
- A Lagrangian approach to simulate accurately the flow forming process as in reality.
- An ALE (Arbitrarily Lagrangian Eulerian) approach to speed up the computation time.
- A 2.5D model approximation taking into account the contact position of the rotating roller allows a geometric prediction of the shapes and the forces of the process in very fast computations.
- An automatic remeshing allowing to adapt the mesh of the part to the conditions of the process and to reduce the calculation time.
- Automatic tools kinematic allowing to calculate the roller speed based on friction for accurate 3D process simulation.
- A 2D flow-forming press allowing to control the displacement of the roller, based on its position of linear speed in the X and Z directions. The rotation speed of the system makes it possible to calculate the contact points of the roller with the part throughout the process.
- Dedicated template that allows a simplified data entry of flow forming.
- An elasto-plastic material model for cold flow forming allowing the prediction of residual stresses in the part.
Flow forming simulation
CASE STUDY: FLOWFORMING OF AN ALUMINIUM WHEEL RIM
The example presented here corresponds to the forming of an aluminium rim. After the forging, drilling and flaring stages also carried out in FORGE®, the flow forming of the part is done by a 2D simulation, with a calculation time of 10 minutes.
The adaptive remeshing enables to have fine mesh in interesting zones: under the roller and in contact with the mandrel.
The material is an aluminium alloy, modelled by an elasto-viscoplastic law.
The final geometry and the thicknesses of the part with the expected geometry.
The simulation results reveal the presence of 2 folds. FORGE® can optimize the stroke of the roller to avoid this defect.
Prediction of the pressure on the wheel and the force on the roller