Elastic properties of a unidirectional SiCf/Ti composite: Acoustic-resonance measurements and micromechanics predictions

Using the mode-selective contactless resonance ultrasound spectroscopy, we measured the complete elastic-stiffness tensor Cij and the corresponding internal-friction tensor Q-1ij of a silicon-carbide fiber unidirectionally reinforced Ti-6Al-4V-matrix composite. This material shows orthorhombic symmetry and possesses nine independent Cij and Q-1ij. We independently excited and detected an unique vibration-mode group among the eight vibration groups of a orthorhombic rectangular parallelepiped. This provides a great advantage in identifying the vibration modes of the observed resonance peaks, whose frequencies yield the Cij by solving an inverse problem. To verify the resultant Cij, we also determined Cij by point-contact resonance ultrasound spectroscopy and pulse-echo methods. Then, using the composite Cij, we inversely calculated the transverse-isotropic fiber elastic stiffnesses with micromechanics theory. With the fiber Cij and the isotropic matrix Cij, we reconstructed the composite Cij as a function of fiber-volume fraction. © 2000 American Institute of Physics.Ogi H., Dunn M., Takashima K., et al. "Elastic properties of a unidirectional SiCf/Ti composite: Acoustic-resonance measurements and micromechanics predictions", Journal of Applied Physics, 87(6), 2769-2774 (2000) https://doi.org/10.1063/1.372254