Targeting Pod Circuit Card Shock Loading Evaluation
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Applied Mechanics Division © 1987-2009 Mercer Engineering Research Center 135 Osigian Blvd. • Warner Robins, GA 31088 info@merc-mercer.org • www.merc-mercer.org • 478.953.6800 MERC was tasked to investigate possible causes for solder joint failures on circuit card assemblies contained in an airborne targeting electronics pod. MERC produced a finite element model of the circuit card assemblies contained in the electronics pod and performed a vibration analysis. The analysis of the CCA’s showed a potential resonance near the first harmonic of the aircraft gunfire vibration. This resonance is sensitive to the amount of support provided by the metal PCB retainers that fasten the CCA’s to the chassis. Visual evidence suggests that these retainers allow the CCAs to deflect a substantial amount. MERC recommended a re-design of these pieces to improve the fatigue life of the CCA’s; this re-design would have minimal impact on the legacy system while improving system reliability. CCA finite element model Modal frequency alignment with gunfire rate decreases the life of the CCA. Targeting Pod Circuit Card Shock Loading EvaluationTargeting Pod Circuit Card Shock Loading Evaluation