Alan Needleman has been a leading innovator in developing the mechanics of large plastic deformation and fracture. His career has been intertwined with the rise of the field of computational solid mechanics. To this field he has made many significant and lasting contributions, usually as the first to demonstrate that computational approaches are both feasible and likely to yield insight.
Needleman performed the first finite element calculations of void growth and coalescence (in early 1970's), of necking in tensile bars (in 1972), of debonding using models which embed cohesive zones (in 1983), and ductile crack growth using models which simulate void nucleation, growth and coalescence (in the early 80's). There are more major contributions. He was one of the first to perform accurate numerical computation of the development of shear band localizations in realistic geometries, and the pictures of emerging bands which came out of the studies where widely regarded as "classics". He has simulated crack growth patterns, including bifurcation and branching, in the dynamic fracture of brittle materials. Most recently, he originated and still drives the effort to develop computational methods to predict macroscopic stress-strain behavior based on discrete dislocation mechanics. In all these cases, his primary contribution has been to lead the way and to demonstrate the feasibility and power of computational approaches to the particular phenomenon.
Needleman is ranked among the most highly cited researchers worldwide, in both the engineering and materials science categories. He served as Dean of Engineering at Brown University, and on the Executive Committee of the Applied Mechanics Division of ASME. He is a member of the US National Academy of Engineering.