M. R. Hill, University of California, Davis, CA
Laser Peening (LP) and Low Plasticity Burnishing (LPB) are two recently emerging surface treatment technologies capable of introducing residual stress deep into a treated surface. While judicious use of these treatments is often of significant benefit to structural component fatigue lives, their misapplication can sometimes lead to excessive component distortion or degrade component fatigue performance through compensating tensile residual stress. Also, during development, there can be a disconnect between successful laboratory treatments and in-field component trials, where slight changes in geometry, loading, and surface treatment application can interact to wreak havoc. Applications of these treatments, therefore, have relied on carefully implemented empirical approaches to provide intended benefits. A computational design tool for residual stress and fatigue analysis could eliminate much of the costly empirical burden imposed by such difficulties. This paper describes a computational design tool applicable to LP and LPB treatments. Although the approach is general and applicable to a range of structural configurations and surface treatments, example results are provided for LP applied to the leading edge of turbine engine airfoils to suppress crack growth due to Foreign Object Damage (FOD).
Summary: Laser Peening (LP) and Low Plasticity Burnishing (LPB) are two recently emerging surface treatment technologies capable of introducing residual stress deep into a treated surface. While judicious use of these treatments is often of significant benefit to structural component fatigue lives, their misapplication can sometimes lead to excessive component distortion or degrade component fatigue performance through compensating tensile residual stress. Also, during development, there can be a disconnect between successful laboratory treatments and in-field component trials, where slight changes in geometry, loading, and surface treatment application can interact to wreak havoc. Applications of these treatments, therefore, have relied on carefully implemented empirical approaches to provide intended benefits. A computational design tool for residual stress and fatigue analysis could eliminate much of the costly empirical burden imposed by such difficulties. This paper describes a computational design tool applicable to LP and LPB treatments. Although the approach is general and applicable to a range of structural configurations and surface treatments, example results are provided for LP applied to the leading edge of turbine engine airfoils to suppress crack growth due to Foreign Object Damage (FOD).
