Prof. Samantha Daly

Department of Mechanical Engineering

Department of Materials Science and Engineering

The University of Michigan, Ann Arbor 48109

Title:

Linking Length Scales: Investigating the Effect of Microscale Strain Localization on Macroscopic Response

Abstract:

The accurate measurement of deformation in response to thermo-mechanical loads is a fundamental requirement in the characterization of materials and structures. Of particular interest is the connection between the macroscopic and microscopic length scales, where strain localization at the grain or constituent level can play critical roles in overall material deformation and ultimate failure of the material. The identification of specific microstructural characteristics that lead to local damage accumulation and accelerated failure, and their mitigation, is key for the informed development and optimization of materials.

This talk will present our recent work on exploring these connections using a combination of distortion-corrected digital image correlation and scanning electron microscopy to measure deformation fields at small length scales, including a creation of functionalized nanoparticles for sub-grain deformation tracking. These approaches enable us to glean critical insights into material behavior, including the impact of constituent architecture on damage accumulation in aerospace composites and the relationship between processing and performance in metallic alloys. Recent studies examining aging effects on the rare earth magnesium alloy WE43 will be discussed as an illustrative example of these emerging experimental approaches and associated analysis. The talk will also include a discussion of on-going work to develop unsupervised learning approaches that statistically link microscale deformation behavior and microstructural attributes.

About the Speaker:

Sam Daly is an Associate Professor in the Department of Mechanical Engineering and in the Department of Materials Science and Engineering at the University of Michigan, Ann Arbor. Her research interests include the mechanical behavior of materials, fatigue, fracture, creep, composites, multi-functional materials, and advanced experimental techniques with a focus on novel approaches for small-scale characterization. She received her Ph.D. and M.S. degrees from the Division of Engineering and Applied Science at Caltech in 2007 and 2002 respectively, and joined the faculty at the University of Michigan in 2008. She is a recipient of the NSF CAREER Award, the Journal of Strain Analysis Young Investigator Award, the Experimental Mechanics Best Paper of the Year Award, the IJSS Best Paper of the Year Award, the DOE Early Career Award, the AFOSR YIP Award, the ASME Orr Award, and the U-M 1938E and departmental faculty excellence awards. Prof. Daly currently serves on the Board of Directors for SES and SMST, and on the editorial boards of Experimental Mechanics and Strain.

Faculty Host: Prof. Kevin Hemker