常温における岩石の二・三の動力学的性質

Abstract

Dynamic properties of marble and granite have been investigated at room temperatures, using bars of these rocks vibrating transversely at audio frequencies in free-free modes. The results are as follows;1. Up to a critical strain amplitude, the internal friction and resonant frequency are almost independent of strain amplitude. When the strain amplitude exceeds this critical value, the internal friction increases and resonant frequency decreases.2. The break point, i. e., the strain at which the internal friction becomes dependent of amplitude shifts to lower strain amplitudes as the relative humidity increases.3. Previous thermal and static stress (cold work) histories experienced by test samples are found to have a large effect on the internal friction.4. The internal friction and the longitudinal wave velocity are both almost independent of frequency with a range between 300 and 5, 000cps.