110 likes | 210 Vues
Magnetometer Booms Vibration Issues Berkeley Composites Laboratory Department of Mechanical Engineering University of California at Berkeley. Overview. Deployment. FGB stowed. FGB deployed on gravity offset fixture. SCB deployed on gravity offset fixture. SCB stowed. Deployment.
E N D
Magnetometer Booms • Vibration Issues • Berkeley Composites Laboratory • Department of Mechanical Engineering • University of California at Berkeley
Deployment FGB stowed FGB deployed on gravity offset fixture SCB deployed on gravity offset fixture SCB stowed
Deployment 1) Frangibolts Actuated 2) Elbow DAD Releases 3) Mid-deployment 4) Fully Deployed
SCB Base Bracket Use larger washers to better support feet. Repeat vibration. Round off corners. Repeat vibration. Fatigue crack in near foot still appear (not clearly shown) Fatigue crack in near foot Machine off existing feet and retrofit wider feet. Repeat vibration. Base bracket with retrofitted feet has no damage. Near foot has no damage; Yielding in far foot
Base Hinge Fretting/ Galling Alodine aluminum clevis Steel washer between clevis and bronze spool (only lower washer visible in picture.) Bronze spool captures base spring. Non-load bearing (vertical direction) FGB and SCB share common hinge mechanism
Base Hinge Fretting/ Galling Clevis inside surfaces Steel washer on clevis Steel washers Steel washer and bronze spring spool Bronze spring spool
Frequency shift Frequency shifts without damage to instrument after random vibration. G10 thermal isolators Missing chamfer (machining error) causes binding of upper stop and clevis.
F1 random vibration F1 booms re-designated F6 flight spare because of the accumulated random vibration time
Random Vibration Specs • Random Vibration Levels (Ref. Swales SAI-TM-2430-Rev D )