Location

Snowmass Village, CO

Start Date

1-1-1995 12:00 AM

Description

In high temperature composites interphases are added between the fibers and the matrix to improve their thermal and mechanical properties. Chu and Rokhlin have determined interphasial elastic properties and interphasial damage for ceramic and intermetallic matrix composites by measuring bulk wave phase velocities along different directions in the composites [1, 2, 3, 4]. Effective interphasial moduli were found from velocity data using micromechanical models. More recently, fatigue damage in the fiber-matrix interphases in SiC/Ti-15-3 composites has been assessed using both the ultrasonic wave velocity and scattering (attenuation) measurements as functions of the stages of the fatigue life cycle [5, 6]. It has been found that the velocity and attenuation (scattering) of ultrasonic waves in these composites are very dependent on the interphase properties due to the large diameters of the fibers. On the other hand the frequency dependences of the wave velocity and attenuation have not been fully studied experimentally.

Volume

14B

Chapter

Chapter 5: Engineered Materials

Section

Composite Properties

Pages

1233-1240

DOI

10.1007/978-1-4615-1987-4_157

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Frequency Dependences of Ultrasonic Wave Velocity and Attenuation in Fiber Composites. Theory and Experiments

Snowmass Village, CO

In high temperature composites interphases are added between the fibers and the matrix to improve their thermal and mechanical properties. Chu and Rokhlin have determined interphasial elastic properties and interphasial damage for ceramic and intermetallic matrix composites by measuring bulk wave phase velocities along different directions in the composites [1, 2, 3, 4]. Effective interphasial moduli were found from velocity data using micromechanical models. More recently, fatigue damage in the fiber-matrix interphases in SiC/Ti-15-3 composites has been assessed using both the ultrasonic wave velocity and scattering (attenuation) measurements as functions of the stages of the fatigue life cycle [5, 6]. It has been found that the velocity and attenuation (scattering) of ultrasonic waves in these composites are very dependent on the interphase properties due to the large diameters of the fibers. On the other hand the frequency dependences of the wave velocity and attenuation have not been fully studied experimentally.