Perforation of Metal Sheets

Ph.D. project: Jens Erik Steenstrup
The main purposes of this dissertation are:
1. Development of a dynamic model for the piercing and performation process
2. Analyses of the main parameters
3. Establishing demands for process improvements
4. Expansion of the existing parameter limits
The literature survey describes the process influence of several parameters. The survey is focused on evaluating the parameter effects using different result parameters. Further, the possibilities of parameter optimisation are described.
Simulation of the process is developed on the basis of existing literature involving the piercing operation. Process simulation is focused on the sheet deformation. However, the effect on the tool and press is included. The process model is based on the upper bound analysis in order to predict the force progress and hole characteristics etc.
Parameter analyses are divided into two groups, simulation and experimental tests. The tests complement each other in order to reveal the dominant parameters, which are decisive for the final product.
Crucial demands are established to enable the desired improvements, focused on expanding the existing parameter limits. The demands include a justified need regarding a high-speed press and a tool designed for punches with minimum length. Further, a systematic problem solving procedure is established. This procedure includes simulation as an integrated part, necessary for problem detection and to predict a favourable solution.