Our Work

Measurement-driven, model-based estimation of residual stress and its effects on fatigue crack growth. Part 1: validation of an eigenstrain model

The objective of this paper is to validate a measurement-driven, model-based approach to estimate residual stress (RS) in samples machined from quenched aluminum stock. Model input is derived from measurement of RS in the parent stock. Validation is performed for prismatic T-sections removed from bars at different locations. We find RS predicted agrees with RS measured, by contour and neutron diffraction methods, with root-mean-square model-measurement difference of 22 MPa. Follow-on work (in Part 2) applies the RS estimation to samples representative of aircraft structures and examines the effects of RS on fatigue crack growth in the RS-bearing samples.

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Case studies

TrueSlot® – near surface residual stress measurement ExpressRS® – expedited residual stress results Strain Gaging Services Residual Stress DART – automated residual stress measurement Mechanical stress relief of aluminum alloys Rapid Forge Design Aluminum forging quench modeling Machining distortion modeling with multi-step models including residual stress BAMpF®

Technical Publications

Measurement-driven, model-based estimation of residual stress and its effect on fatigue crack growth. Part 2: fatigue crack growth testing and modeling Measurement-driven, model-based estimation of residual stress and its effects on fatigue crack growth. Part 1: validation of an eigenstrain model Near Surface Residual Stress Measurement Using Slotting Measurement Layout for Residual Stress Mapping Using Slitting Precision of Hole-Drilling Residual Stress Depth Profile Measurements and an Updated Uncertainty Estimator An Uncertainty Estimator for Slitting Method Residual Stress Measurements Including the Influence of Regularization Validation of a Contour Method Single-Measurement Uncertainty Estimator Repeatability of Contour Method Residual Stress Measurements for a Range of Materials, Processes, and Geometries PSR Biaxial Residual Stress Mapping Validation The Contour Method (book chapter)