DIFFERENCES BETWEEN STATIC AND DYNAMIC ELASTIC MODULI OF ROCKS: PHYSICAL CAUSES

Abstract

Elastic moduli are controlled mainly by the viscoelastic and microplastic behavior of rocks if stress and strain remain below the proportionality limit. Differences between measured static and dynamic elastic moduli are caused by different inelastic contributions to stress-strain relationships which behave as a function of strain amplitude and frequency (energy and strain rate). Static and dynamic elastic moduli can be appropriately compared at equal strain amplitudes and frequencies and at identical physical properties of solids. Nonlinear seismics, inelastic behavior, hysteresis, strain amplitude dependence of wave velocities and attenuation, static and dynamic elastic moduli