Thermal Modeling Techniques of Heat Assisted Single Point Incremental Forming in ANSYS Workbench

Single Point Incremental Forming (SPIF) is a manufacturing process used to form sheet materials, similar to thermoforming or stamping, that does not require the use of molds or dies. SPIF uses a CNC machine, with a blunt end forming tool, to incrementally form a sheet material into the desired shape of the final part. One disadvantage of SPIF is that after the tool is removed from the sheet material there is often springback due to small sections of the material that have not surpassed the material yield strength and have not permanently deformed. Past research [4] shows with the application of high temperature fluid flow, accuracy of the SPIF process, as well as formability of the material, is increased when used on polymers. Heat assisted SPIF will still result in some material springback and low accuracy parts, requiring need for further analysis of the heat assisted SPIF process. The objective of this research is to create an accurate method for analyzing heat assisted SPIF of polymers in ANSYS workbench and to use the ANSYS analysis to improve the accuracy of the final part in reference to the desire CAD model. This work will present methods for modeling the temperature profiles of the polymer sheets during the heat assisted SPIF process within ANSYS workbench. The temperature profiles of the polymer sheet during different stages of the heat assisted SPIF process will be examined and methods to apply the thermal profile to a coupled ANSYS simulation will be presented. The methods discussed in this work include CFD analysis of the heated fluid flow, direct application of the temperature loads to an applied face mesh or Z-level mesh, and the use of thermal conduction due to an applied tool temperature. Each method of applying the temperature profile to the polymer sheet is analyzed for accuracy, computation time, and the difficulty of the setup within ANSYS workbench. The results show that while the CFD analysis method most resembles the experimental setup, the Applied Face Mesh (AFM) method shows the highest accuracy when compared to the temperature profile seen during experimentation, while also having a low computation time. While this paper shows possible methods for modeling the temperature profile of the polymer sheet during heat assisted SPIF, future research will show more results as to how each method affects the accuracy of the final heat assisted SPIF simulation in ANSYS workbench