The Engineering Residual Stress Implementation (ERSI) Working Group

The Engineered Residual Stress Implementation (ERSI) working group was formed in 2016 with a mission to develop a holistic paradigm for the implementation of engineered residual stresses into lifing of fatigue and fracture critical components. ERSI emerged from within the United States Air Force (USAF) aircraft structural integrity community, with the primary focus so far being on cold expansion of holes and associated life extension.

ERSI is comprised of six primary focus areas that represent different technical disciplines of aircraft structural integrity: 1) fatigue crack growth analysis, 2) validation testing, 3) residual stress measurement, 4) nondestructive inspection/evaluation and quality assurance, 5) residual stress process simulation, and 6) risk assessment and uncertainty quantification.

An overview of the activities of the ERSI working group will be presented, including round robin efforts related to residual stress measurements, FE process simulations of cold expansion of holes, fatigue crack growth analyses incorporating residual stresses, stress spectrum effects, and stress intensity factor comparisons.