Walter P. Murphy Professor Emeritus

BS, physics, 1948

DSc physics, 1951 Carnegie Institute of Technology (now Carnegie Mellon University)

Contact Info

 

Dislocation theory; mechanical properties of metals

     Our research areas are the mechanical properties of metals, including fatigue and fracture of metals, the high-temperature creep of crystalline solids, and dislocation theory applied to these phenomena. We are developing dislocation-based solutions of the plastic regions around stressed cracks. These solutions rely on dislocation crack tip shielding and dislocation crack extension force conditions. In fact, we believe that complete solutions for crack problems in elastic plastic solids cannot be obtained, except for the most simple problems, without use of the dislocation equations. In the area of geophysics, we recently developed a theory for the migration of subglacial lakes under ice sheets and earthquake dislocations moving at a transonic velocity on a fault separating rock of sightly different elastic constants.
     In the area of geophysics, our primary research area is in the theory of the flow of glaciers and ice sheets.
     Prof. Weertman has an island in Antarctica named after him.

Associations and Awards

Walter P. Murphy Professor Emeritus of Materials Science and Engineering

Member, American Academy of Arts and Sciences, 1997

Seligman Crystal of the International Glaciological Society, 1983

Acta Metallurgica Gold Medal, 1980

Champion H. Mathewson Gold Medal of the Metallurgical Society of AIME for work on creep and fatigue fracture, 1977

Member, National Academy of Engineering, 1976

Guggenheim Fellowship, 1970

Robert E. Horton Award, American Geophysical Union, 1962

Fulbright Fellowship, 1951

Fellow, Geological Society of America, 1970; ASM International, 1972; American Physical Society, 1982; American Geophysical Union, 1982; TMS–AIME, 1990; American Academy of Mechanics

Publications

J. Weertman, Asymptotic crack tip stress, rotation pseudo-stress field and dislocation fields for mixed mode I and II cracks in elastic perfectly plastic solids, Mechanics of Materials. 35, pp. 433-452 (2003).

J. Weertman, Relationship between stress-strain potentials and maximum shear and zero shear trajectories for mode III crack, in Electron Microscopy: its Role in Materials Science (The Mike Meshii Symposium), edited by J.R. Weertman, M. Fine, K. Faber, D. Quesnel, W. King and P. Liaw, The Minerals, Metals & Materials Society (TMS), Warrendale, PA, pp. 107-112 (2003).

Subsonic-type earthquake dislocation moving at approximately 2^1/2 x shear wave velocity on interface between half spaces of slightly different elastic constants. Geophys. Res. Lett. 29: art no. 1470 (2002).

Why the stress trajectories in the Dean-Hutchinson plastic sector of the growing mode III crack are an unfocused fan. J. Mech. Phys. Solids 50: 153-63 (2002).

Anomalous work hardening, non-redundant screw dislocations in a circular bar deformed in torsion, and non-redundant edge dislocations in a bent foil, Acta Materialia 50, pp. 673-689 (2002).

The Comninou-Dundurs Effect and position stability of subglacial lakes, Annals of Glaciology 35, pp. 495-502 (2002).