Passively Adaptive Viscous Damping Mechanism

TO PROLONG LIFE AND ENHANCE THE PERFORMANCE OF SDI AND OTHER SPACECRAFT STRUCTURES, THE EFFECTS OF STRUCTURAL DYNAMICS MUST BE REDUCED. PASSIVE DAMPING HAS BEEN DEMONSTRATED AS AN EXCELLENT MEANS FOR VIBRATION SUPPRESSION, EITHER ALONE OR IN CONCERT WITH ACTIVE CONTROL. THE IDEAL PASSIVE DAMPING SOLUTION FOR SPACE APPLICATIONS WOULD BE LIGHTWEIGHT AND EFFECTIVE OVER WIDE RANGES OF FREQUENCY AND TEMPERATURE. NONE OF THE CURRETNLY AVAILABLE OPTIONS FOR PASSIVE DAMPING SATISFY ALL THESE CRITERIA. THE GOAL OF THIS EFFORT OS TO DEVELOP A VISCOUS DAMPING MECHANISM THAT WILL ADAPTIVELY CHANGE TO PROVIDE PASSIVE DAMPING THAT IS NEARLY CONSTANT WITH RESPECT TO TEMPERATURE AND THEREFORE CLOSER TO THE IDEAL THAN ANY OTHER FORM OF DAMPING. THIS INNOVATIVE CONCEPT WILL BE COMPLETELY PASSIVE: CHANGES IN TEMPERATURE WILL DIRECTLY AFFECT THE DAMPING MECHANISM WITH NO NEED FOR EXTERNAL POWER. THE LOSS MECHANISM OF VISCOUS DAMPERS RELIES ON FORCING FLUID THROUGH A PASSAGE. WHEN ITS TEMPERATURE CHANGES, THE FLUID'S VISCOSITY CHANGES, AND THIS DIRECTLY EFFECTS THE LOSS CHARACTERISTICS OF THE DAMPING MECHANISM. THE PHASE I EFFORT WILL DEMONSTRATE THE FEASIBILITY OF USING THERMAL EXPANSION PROPERTIES IN AN INNOVATIVE MANNER TO COMPENSATE FOR CHANGES IN THE FLUID'S VISCOSITY BY ALTERING THE INTERNAL MECHANICS OF THE DAMPER. A PROTOTYPE DAMPING MECHANISM WILL BE DESIGNED, BUILT, AND TESTED OVER A REPRESENTATIVE TEMPERATURE OF THESE MECHANISMS FOR AEROSPACE APPLICATIONS.