Tuesday  |  Frick  |  02:40 PM–03:00 PM

#13316, The Power and Limits of Superposition and Residual Stress Analysis

Bueckner’s superposition principle was first applied to the analysis of residual stress measurements by Gary Schajer in 1981. It largely enabled the accurate measurement of residual stresses by making the data analysis calculations accurate. Before then, the issue of stress re-arrangement during material removal had plagued attempts to accurately analyze data. Since then, superposition has revolutionized many aspects of residual stress and spawned numerous attempts to come up with the best inverse solution methodology. This talk first briefly reviews the historical path from Bueckner to Barenblatt to Iain Finnie that led Schajer to Bueckner’s principle, with a detour to Paul Paris’ landmark paper on fatigue crack growth. The talk will then attempt to explain and demonstrate the principle in a simple manner to promote intuitive understanding. The talk then explains how this superposition principle has revolutionized residual stress analysis with examples from hole drilling, slitting, and the contour method. The talk will then show cautionary examples where researchers have applied Bueckner’s principle beyond its limits. The talk will also discuss why some researchers still refuse to believe Bueckner’s principle works, in spite of overwhelming proof of its validity when applied appropriately.

Michael Prime   Los Alamos National Laboratory