A METHOD OF MAKING COMPOSITES WITH PASSIVE VIBRATION DAMPING EFFECT

摘要

"A method for passive damping on composite materials" This invention relates to a method of passive vibration damping composite materials such as Kevlar & Graphite composites with embedded Kevlar flexcore at ambient & varying temperatures using surface activation technique of Plasma etching along with thin hybrid layers (on one side only) of high sensitivity ferro-electrically soft & hard piezoelectric ceramic material layers. The surface activation is done using Plasma etching technique for getting better adhesion of piezoceramic material with composites. Hydrophilic polymers such as KFRP (Kevlar Fiber Reinforced Plastic) & Hydrophobic Graphite Composites were treated with Radio Frequency (RF) plasma to modify the surface properties such that they get reflected in the adhesion enhancement between plasma treated polymer surfaces and the thin piezoceramic material coating at elevated temperatures. It has been found that there is significant passive damping contribution at resonant frequencies from the thin hybrid piezoelectric coatings on one side of the substrate composite materials like Graphite & Kevlar fiber with embedded Kevlar flexcore at elevated space domain temperatures. (Fig 1)