Portable Ultrasonic Shot Peening Repair of Helicopter Components

Portable Ultrasonic Shot Peening Repair of Helicopter Components

 

John A Gran, George G Liu, Jung-Hua Chang, and Michael J Kane

U.S. Army RDECOM, Aviation and Missile RDEC, Aviation Engineering Directorate

Redstone Arsenal, Alabama, 35898

U.S.A.

Randy Buckner and Robert Bilbrey

Avion Solutions, Inc

Huntsville, Alabama 35805

U.S.A.

 

Abstract: 

Many helicopter dynamic components are fatigue critical and depend on shot peening to enhance fatigue life and lessen the impact from field induced surface damages.  These components require conventional peening at Army approved vendors during manufacturing or overhaul repair.  A common question asked during overhaul or field repair is:  Can these components be repaired with a portable shot peening device in the field rather than shipping the parts back to the shot peening vendor?  This ability would significantly increase readiness and reduce repair and life cycle costs.  Through a Small Business Innovative Research project, a test plan was developed by the Aviation Engineering Directorate of the U.S. Army Research, Development, and Engineering Command, and carried out in conjunction with Avion Solutions, Inc.  The effort includes a detailed comparative analysis of ultrasonic shot peening versus conventional shot peening on commonly used metallic alloys, optimization of ultrasonic shot peening parameters, and understanding its impact on fatigue strength.  Based on the study, several helicopter components have been selected for use of the portable ultrasonic peening repair.  Some examples of actual repairs of helicopter dynamic components will be presented.  Also, the variation of the ultrasonic parameters and their impact on peening intensity in one particular field repair application will be discussed.