Advisor

Tian, Wenmeng (Meg)

Committee Member

Morshedlou, Nazanin

Committee Member

Ma, Junfeng

Date of Degree

8-1-2020

Original embargo terms

Visible to MSU only for 6 months||forever||5/15/2021

Document Type

Graduate Thesis - Open Access

Degree Name

Master of Science

Abstract

Quality assurance has been one of the major challenges in laser-based additive manufacturing (AM) processes. This study proposes a novel process modeling methodology for layer-wise in-situ quality monitoring based on image series analysis. An image-based autoregressive (AR) model has been proposed based on the image registration function between consecutively observed thermal images. Image registration is used to extract melt pool location and orientation change between consecutive images, which contains sensing stability information. Subsequently, a Gaussian process model is used to characterize the spatial correlation within the error matrix. Finally, the extracted features from the aforementioned processes are jointly used for layer-wise quality monitoring. A case study of a thin wall fabrication by a Directed Laser Deposition (DLD) process is used to demonstrate the effectiveness of the proposed methodology.

URI

https://hdl.handle.net/11668/18439

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