Competencies in residual stress measurement

• Relaxation methods (destructive)
  • Contour method (bulk, uniaxial, 2-D stress map on a single plane)
    See Mike Prime's site for a nice explanation of this method.
  • Crack-compliance method (bulk, uniaxial, distribution with depth, on a single plane)
    Once again, Mike Prime has a nice explanation of this method.
  • Hole-drilling (near surface, biaxial, uniform or linear distribution with depth, at a single point)
    This link at Measurements Group explains the method in detail.
  • Eigenstrain method (bulk, triaxial, whole- or partial-field distribution)
    This paper has more information.
• Diffraction methods (potentially non-destructive)
  • X-ray diffraction (biaxial surface measurement, single point)
  • Neutron diffraction (triaxial, bulk stress, single cubic neighborhood)

Competencies in residual stress effects

• Inclusion of residual stress in elastic-plastic finite element modeling
  • Eigenstrain analysis
  • Modeling of residual stress effects in fracture
  • Modeling of residual stress effects in fatigue
  • This paper has more information.
• Weight function analysis for elastic predictions of residual stress effects in fracture and fatigue

Applicable Equipment

• Full strain-gage instrumentation facility
• Wire electric-discharge machining (EDM) facility available through Professor Yamazaki's
  IMS-Mechatronics Laboratory
• Scintag XDS2000 X-ray diffractometer located in ChEMS
• ND must be carried out at a national facility, such as the Los Alamos Neutron Science Center (LANSCE)

Results

• Please refer to references section of Prof. Hill's home-page for examples of our work.