# Numerical Simulation and Analysis of the Manufacturing Process of Pre-Bulged Rupture Discs
## 4 Conclusions  
In the scope of this contribution, the authors established a robust, accurate and reliable numerical simulation model for analyzing all steps of the bulge-forming process of rupture discs. The simulation model involves all relevant process steps and parameters such as friction/contact between the clamping unit and the metal membrane, experimentally validated nonlinear material behavior, finite strains, etc. Extensive experimental investigations from an industrial production process confirm the validity of the simulation results. The systematic experimental evaluation of the simulations has shown that the deformation variables considered in the bulge-forming process are highly sensitive to the mechanical properties of the primary material. Even small variations in these variables can have a significant influence on the forming result. Therefore, this must be taken into account if the primary material comes from one and the same batch, as the entire manufacturing process of a cold-rolled strip must be considered. When carrying out numerical bulge-forming simulations, it is recommended to identify the required material parameters individually in preliminary tests. This approach should account for not only the chemical composition of the material under consideration but also its forming history and the heat treatment process it has undergone. A thorough material characterization is essential in view of the fact that bursting discs are safety-relevant components for pressure protection in process engineering systems including extremely critical process boundary conditions. However, the obtained results may serve as a basis for process engineers when adjusting the process parameters to achieve a pre-defined bulge shape for rupture discs. In addition, the results provide a comprehensive understanding of the stress-strain behavior of rupture discs, which is essential for sizing and positioning the pre-notches (single-layer design) or perforations (multi-layer design). The validated numerical model also provides the capability to perform comprehensive parameter studies for different materials with different plastic flow behavior in the future. Furthermore, it will be possible to analyze the physical behavior under different geometric conditions, such as various bulge diameter-to-thickness ratios or the influence of the bending radius dimension on the deformation behavior. By taking into account the contact between the outer edge of the bursting membrane and the clamping tool, different contact boundary conditions, such as different friction values or contact normal pressures, can also be investigated.  
Conceptualization, B.T. and D.A.; methodology, B.T.; software, B.T.; validation, B.T., D.A. and K.W.; formal analysis, B.T., D.A. and K.W.; investigation, B.T.; resources, B.T. and D.A.; data curation, B.T.; writing--original draft preparation, B.T. and D.A.; writing--review and editing, B.T., D.A. and K.W.; visualization, B.T.; supervision, D.A.; project administration, B.T. and D.A.; funding acquisition, D.A. All authors have read and agreed to the published version of the manuscript.  
This research has been developed within the project PLan_CV and was funded in the scope of the funding program FH-Personal (grant number 03 FHP109) by the German Federal Ministry of Education and Research (BMBF) and Joint Science Conference (GWK).  
Not applicable.  
The data as well as simulation models presented in this study are available on request from the corresponding author.  
The corresponding author [PERSON] (D.A.) acknowledges on behalf of all authors the support of the company _STRIKO Verfahrenstechnik GmbH, Reichshof, Germany_, which provided all rupture disc samples and the production machines for the bulge-forming process as well as the measuring equipment for experimental analysis.  
The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analysis, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.