Lecture Shamsaei - Crack Paths 2027

Additive manufacturing (AM) is changing how we design and manufacture components, while it also challenges some of the assumptions that have traditionally guided materials qualification. One important question is whether properties measured from standardized test specimens can truly represent the behavior of the components they are intended to qualify. For additively manufactured metallic parts, the answer is not always straightforward. Thermal history can change with component size and geometry, while build orientation, location within the build, processing conditions, and local defect populations can lead to significant variations in mechanical behavior, even within a single build. These effects are particularly important for fatigue-critical applications, where relatively small differences in microstructure or defects can strongly influence crack nucleation and small crack growth.

This presentation explores the challenges these AM-specific characteristics create for conventional qualification approaches and asks a fundamental question: how can we build confidence in the fatigue performance of a component when the material itself is closely tied to the manufacturing process and the geometry of the part? Addressing this challenge requires connecting process history to material structure, mechanical behavior, and ultimately component performance. The presentation will discuss opportunities to develop these process-structure-property-performance relationships through experiments, physics-based modeling, and data-driven approaches. Such efforts could enable more efficient and component-relevant qualification strategies, helping AM move beyond demonstrating manufacturing capability toward achieving predictable and certifiable performance in fatigue-critical applications.