Tailored Structural Damping from Embedded Nano-Composite Layers 2006-01-3649

As the use of carbon fiber reinforced polymer composites become more common for high performance component design, the need to further tailor the materials properties to specifically suite a specific application is desired. Increases in intrinsic material damping, especially for that of load bearing components, can reduce harmonic stresses which are transmitted through a structure, decrease the overall weight of a structure, and reduce vibration induced fatigue of drivers.

This paper explores the use, and effects of lamina placement, of carbon nano-fiber reinforced constrained interlaminar shear layers. These nanofiber shear layers can be a replacement for carbon nano-tube reinforced interlaminar shear layers, which have shown increased in intrinsic damping with little or no loss of flexural modulus, for use in spring or flexure designs which require elevated intrinsic material damping. The use of carbon nanofibers produces an economic alternate to carbon nano-tubes allowing the production of light weight, stiff structural members which utilize high intrinsic material damping. A combination of numerical modeling, and material performance indices are used to refine the number of possible laminate geometries which retain high modulus and show increases in total damping levels.

A number of studied geometries show retention of high dynamic modulus along with increases in intrinsic material damping. The predicted increase in intrinsic material damping gives design engineers further control of the behavior and performance of carbon fiber reinforced springs or flexures.