Session: 03-02-01: Advanced Manufacturing

Paper Number: 152032

152032 - Thermal Calibration of Finite Element Models in Wire Arc Directed Energy Deposition of Er-120S-G Using Thermocouples and Infrared Cameras 

As wire arc-directed energy deposition (WA-DED) continues to gain widespread acceptance in the manufacturing industry, the development and application of metallic alloys like 2219-Al, Ti-6Al-4V, Inconel 718, and stainless steel are increasing rapidly. However, optimizing process efficiency and achieving the desired outcomes through physical trials can be both expensive and time-consuming. This challenge underscores the importance of developing accurate and precise Finite Element Models (FEMs) that allow for cost-effective simulations. In this study, we focus on the thermal calibration of a FEM for ER120S-G, the high-strength steel alloy typically used for large vehicles and heavy construction equipment, utilizing thermocouples and infrared (IR) imaging as calibration tools.

Thermocouples were deployed at specific locations on the substrate to measure temperature with high accuracy, while an IR camera was used to create a detailed heat map of the part’s surface during the WA-DED process. To ensure the IR camera provided accurate temperature readings, an experiment was conducted to calibrate its emissivity settings. A block of ER120S-G was heated, and the temperature data collected by the IR camera was compared with the thermocouple readings. This experiment was carried out on both machined and non-machined ER120S-G surfaces to evaluate the impact of surface conditions on the emissivity of the material. For the primary calibration experiment, five thermocouples were positioned on the substrate, with the IR camera placed at a downward angle, providing a comprehensive view of the thermal profile.

The FEM was created using Abaqus, employing the Goldak double-ellipsoid heat source model to simulate the thermal history of the WA-DED process. The parameters defining the Goldak model, including depth, width, and front and back lengths, were systematically varied to study their influence on thermal history, stress distribution, and deflection. Results showed that heat transfer coefficients and power efficiency had the greatest influence on the overall thermal history, while the Goldak parameters primarily affected the immediate vicinity of the melt pool. Given that heat transfer coefficients are influenced by surface-to-surface contact conditions, the heatsink effect emerged as a critical factor affecting the thermal profile.

The FEM was calibrated by adjusting both the heat transfer coefficients and power efficiency to match the experimental data obtained from the thermocouples and the IR camera. After calibration, the model was used to simulate prints with varying parameters. Validation of the FEM was confirmed when the thermal history predicted by the model aligned closely with the experimental thermal data. Once validated, this model can be reliably used to simulate the thermal history of prints under different process parameters, enabling more accurate predictions of mechanical performance and reducing the need for costly physical trials.

Presenting Author: Joshua Bassett Center for Advanced Vehicular Systems

Presenting Author Biography: I'm a graduate student at Mississippi State University with my goal on getting a masters in aerospace engineering. I currently work at the Center for Advanced Vehicular Systems as a research assistant.