2011 Articles

Experimental study of attenuation and dispersion over a broad frequency range: 1. The apparatus

Takei, Yasuko; Fujisawa, Kazuhiro; McCarthy, Christine

We have developed a new experimental method to investigate the anelasticity of a polycrystalline solid at high homologous temperature (T/Tm = 0.6–0.7). By using a rock analogue (borneol polycrystals) and a partially molten rock analogue (borneol + melt) having low melting and eutectic temperatures (Tm = 204.5°C, Te = 43°C), respectively, testing high homologous temperature can occur near room temperature. An apparatus is described for cyclic compressive, Young's modulus type attenuation experiments over a wide range of frequencies (10–10−4 Hz) and at small strain amplitudes (10−6–10−5). Creep tests to measure steady state viscosity can also be performed. Details of the apparatus, including its piezoelectric actuator, dual laser displacement meters and trio of load cells, are discussed. Attenuation spectra and modulus dispersion measured for aluminum, acrylic plastic, and a rock analogue are presented to illustrate the accuracy of the method.