Dr. Kirk Retrospective: Alternative Scaling of Almen Strip Saturation Curves

Author:  Donovan Stumpf, R. Varma, L. Feltner, P. Mort | Purdue University
Source:  The Shot Peener magazine, Vol 40, Issue 1, Winter 2026
Doc ID:  2026005
Year of Publication:  2026
Abstract:  
INTRODUCING THE DR. KIRK RETROSPECTIVES Dr. David Kirk’s articles in The Shot Peener have long been among the most valuable resources for both new members of the peening community and its seasoned practitioners. Known for translating complex ideas into clear, practical explanations, Dr. Kirk bridged the gap between theory and application — a connection that remains as vital today as when his first papers were published. Whether addressing the fundamentals of peening or the finer details of Almen strip composition, his writing continues to make the science more accessible. Now, a new generation of researchers is carrying that legacy forward. Under the direction of Dr. Paul Mort of Purdue University’s School of Materials Engineering, Donovan Stumpf, Rajeshree Varma, and Langdon Feltner will reflect on Dr. Kirk’s conclusions and explore how his ideas continue to evolve in the era of advanced materials and digital manufacturing. Each article in the Dr. Kirk Retrospectives series will revisit a cornerstone of his work, pairing his vital insights with new research — honoring the past while charting the future of peening innovation. This article explores how an energy-based approach can extend Dr. Kirk’s bending model of the Almen strip. The main idea is that when Almen saturation data are scaled by peening energy rather than time, the results from different peening conditions and strip thicknesses can align on a single, unified curve.