Distortion Compensation for Additive Manufacturing Development, Validation, and Pitfalls
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The thermal mechanical processing that takes place in metal additive manufacturing can result in appreciable residual stresses that can cause distortions in as designed geometries [1]. These distortions can result in parts that do not meet geometric requirements. Furthermore, for designer engineers, there is not a clear path towards mitigating these distortions; changing part geometry, adding material to increase stiffness, and/or trial and error are used in hopes of achieving an acceptable design. Distortion compensation wherein a simulated part distortion is used in an inverse modeling framework to intentionally evolve a design can help to overcome these obstacles. In this work, we develop a simulation-based framework for distortion compensation for metal additive manufacturing. This approach allows an original design geometry to be evolved such that the printed part satisfies the as designed geometric requirements without requiring trial and error build iterations. This talk will expand upon previous work [2] and share the development of a distortion compensation capability including 1) an automated meshing workflow for additive manufacturing, 2) a thermal mechanical inherent strain approach for distortion simulation, 3) an inverse finite element modelling approach used to evolve design geometry, and 4) validation study data. Additionally, the current limitations, successes, and struggles with this approach will be discussed. These results endeavour to improve the agility and accuracy of the metal additive manufacturing capabilities within a reasonable design timeline. Future work will expand the existing validation basis to include additional materials and geometries and continue to evolve the numerical and simulation frameworks to improve efficiency and accuracy. REFERENCES [1] Mukherjee, T., Zhang, W., & DebRoy, T. (2017). An improved prediction of residual stresses and distortion in additive manufacturing. Computational Materials Science, 126, 360-372. [2] Herriott, C. F., Stender, M., Johnson, K. L., White, B. C., Crandall, C. L., Shinde, S. C., ... & Hegde, A. S. (2024). Distortion compensation for metal additive manufacturing: verification, validation, and development of a thermal mechanical workflow (No. SAND2024-09416C). Sandia Natio
