MODULI DETERMINATION OF CONTINUOUS FIBER CERAMIC COMPOSITES (CFCCS)

Nicalon(TM)/silicon carbide composites were fabricated by the Forced C hemical Vapor Infiltration (FCVI) method. Both through-thickness and i n-plane (fiber fabric plane) moduli were determined using ultrasonic t echniques. The through-thickness elastic constants (moduli) were found to be much less than the in-plane moduli. Increased porosity signific antly decreased both in-plane and through-thickness moduli. A periodic model using a homogenization method was formulated to predict the eff ect of porosity on the moduli of woven fabric composites. The predicte d moduli were found to be in reasonably good agreement with the experi mental results.