05-11-2026 - Lecture Hall B

PhD Presentation

From microstructure to fracture: Modeling the ductile-to-brittle transition in recycled steel

Amrit Jena

Recycled steel is central to decarbonizing construction, but scrap-based routes bring higher residual element contents and wider inclusion populations, adding uncertainty to their mechanical behavior. At service temperatures, this shifts the ductile-to-brittle transition and lowers the upper-shelf energy. Predicting this requires a fracture model with physically meaningful parameters, rather than ones fitted to a single test.
In this talk, I show how Gurson-type ductile damage parameters can be derived from SEM inclusion statistics and transferred across loading rates and specimen geometries without recalibration. The real challenge in my PhD lies in the transition region, where a crack starts with ductile tearing and ends in cleavage. I discuss how coupling the ductile model with a multi-barrier cleavage model can capture this sequence and help predict the behavior of recycled steels.