4/25/2014 Julia Cation
Written by Julia Cation
MechSE hosted the 2014 Arthur Newell Talbot Distinguished Lecture yesterday, April 24, 2014, at the NCSA auditorium. Alan Needleman, professor of materials science and engineering at the University of North Texas, spoke on “Modeling Ductile Fracture Toughness and Fracture Surface Roughness.”
The abstract for his lecture stated: “Two fundamental questions in the mechanics and physics of fracture are: (i) What is the relation between observable features of a material’s microstructure and its resistance to crack growth? and (ii) What is the relation between observable features of a material’s microstructure and the roughness of the fracture surface? An obvious corollary question is: What is the relation, if any, between a material’s crack growth resistance and the roughness of the corresponding fracture surface? I will discuss results of 3D finite element calculations of modeI ductile crack growth aimed at addressing these questions. In the calculations, ductile fracture of structural metals by void nucleation, growth, and coalescence is modeled by an elastic-viscoplastic constitutive relation for a progressively cavitating plastic solid. A material length scale is introduced via a discretely modeled microstructural feature, such as the spacing of inclusions that nucleate voids. Possible connections between quantitative measures of crack growth resistance and quantitative measures of the statistics of the fracture surface roughness are investigated and related to the nature of the ductile crack growth process.”
Needleman completed his PhD in engineering at Harvard University, and is a member of the National Academy of Engineering and the National Academy of Arts and Sciences. He holds honorary doctorates from the Technical University of Denmark and Ecole Normale Superior de Cachan (in France).
Arthur Newell Talbot was named Professor of Municipal and Sanitary Engineering in charge of Theoretical and Applied Mechanics at Illinois until 1926, and regarded teaching as the most important aspect of his work at the university. The Arthur Newell Talbot Distinguished Lecture is made possible through the support of the Talbot family, in honor of their ancestor’s commitment to learning and teaching.