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GALCIT Special Seminar

Tuesday, April 25, 2023
4:00pm to 5:00pm
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Gates-Thomas 135
*CANCELLED* Revisiting Linear Elastic Fracture Mechanics
Angkur Shaikeea, Ashby Postdoctoral Research Fellow, Department of Engineering, University of Cambridge,

Note: Due to unforeseen circumstances, this talk has been cancelled.

Additive manufacturing has led to significant advancements in the creation of lightweight solids with report of extreme mechanical properties in stiffness, strength, and auxetic behaviour. However, there is still much to learn about the damage tolerance of these solids to proliferate as engineering materials. The validity of continuum ideas of fracture has not been fully tested, and the well-established stress intensity factor is insufficient to describe the damage tolerance in 3D architected solids. As a result, 50-year-old theories and test protocols in linear elastic fracture mechanics require revision. For instance, plane strain is not a conservative toughness for these solids.

In the pursuit of testing continuum ideas of elastic fracture mechanics in 3D discrete systems, a fascinating observation was made — Elastic brittle architected solids exhibit a rising R-curve, similar to ductile solids, leading to unexpected toughening in a brittle system. This finding can open new horizons in the physics of solids and spur the development of theories like strain gradient elasticity. Large-scale numerical calculations and development of techniques in in-situ measurements with micro-tomography have deciphered the elusive behaviour of micromechanics of mechanical metamaterials. These experimental techniques, including lab-based tomography and full-field 3D microscopic strain measurements in continuum solids using Digital Volume Correlation, stand out as new technologies in experimental mechanics. Not only do they enhance our understanding of materials, but they also enable the design of materials using data-driven mechanics in a variety of applications.

For more information, please contact Nathaniel Wei and Peter Gunnarson by email at [email protected].