MEMBRE D’HONNEUR 2024

Alan NEEDLEMAN

Distinguished Professor of Materials Science and Engineering, Texas A&M University, USA

Alan Needleman studied Mechanical Engineering at the University of Pennsylvania beginning in 1962 and received his B.S. degree in 1966. He then entered graduate school at Harvard University where he majored in Solid Mechanics and minored in Materials Science and Applied Mathematics. In his PhD work, supervised by Professor John Hutchinson, he developed one of the first finite deformation elastic-plastic finite element programs and used that program to model plastic void growth. The finite element method was developed by structural engineers in the 1950s to carry out stress analyses of aerospace and civil engineering structures. In the late 1960s John Hutchinson, Jim Rice and a few others realized that the finite element method was an ideal tool for solving plastic deformation and fracture problems that are too complex mathematically to permit an analytical solution. Thus began a revolution in the way the Solid Mechanics modeling of mechanical material behavior is carried out.

Alan finished his PhD work in 1970 and moved to the Massachusetts Institute of Technology (MIT) as an Instructor (1970-1972) and then Assistant Professor (1972-1975) in Applied Mathematics. While at MIT Alan carried out finite element calculations of tensile bars where necking emerged as a bifurcation (sort of the tensile analog of buckling of a column). In 1973, Alan spent a semester visiting the Technical University of Denmark where he began a fruitful and enjoyable collaboration with Viggo Tvergaard that has lasted more than 50 years.

In 1975 Alan joined the Solid Mechanics group at Brown University as an Assistant Professor and was fortunate to have a group of distinguished and supportive senior colleagues/mentors, including Jim Rice, Rod Clifton, Ben Freund, Jacques Duffy and Harry Kolsky, who created a collaborative and collegial work environment. Also, faculty in Solid Mechanics at Brown were encouraged to focus on carrying out quality research that could, at least in principle, have both a research and an engineering impact; funding, citations, number of students were not considered in faculty evaluations.

At Brown, Alan benefited from interacting with excellent colleagues, talented and fun-to-work-with national and international collaborators, and a wonderful group of students and post-docs. This enabled him to contribute to a range of materials modeling topics including stability of plastic deformation, ductile fracture, a cohesive surface formulation for modeling crack nucleation and crack growth, fatigue, plasticity of single crystals and polycrystals, and discrete dislocation plasticity. Alan served as Dean of Engineering from 1988 to 1991 and became the Florence Pirce Grant University Professor in 1996.

In 2009, Alan retired from Brown and joined the Department of Materials Science and Engineering at the University of North Texas (UNT). At UNT, inspired by experiments of Elisabeth Bouchaud (then at CEA-Saclay) and her colleagues, Alan worked on modeling the fractal scaling of ductile fracture surface roughness and its connection with a material’s crack growth resistance.

Alan moved to Texas A&M University in 2015 where he is now Professor of Materials Science and Engineering, holder of the Royce E. Wisenbaker ’39 Chair II and University Distinguished Professor. Alan continues working on modeling plastic deformation and fracture of materials. He has added meso-scale modeling of plasticity of amorphous solids, analyzing implications of a local, short time negative dissipation rate for plastic deformation modeling and identification of plastic material parameters using Bayesian statistics to the range of topics he works on.

At UNT and at Texas A&M, as at Brown, Alan has benefited from and enjoyed working with excellent colleagues, wonderful students and post-docs, and talented national and international collaborators.