Elastic limit of x-cut quartz under shockless and shock wave compression: Loading rate dependence

To examine the effect of compressive loading rate on the elastic limit of brittle solids, shockless and shock wave uniaxial strain experiments were conducted on x-cut quartz to a peak stress of $11GPa$⁠. Using a compact pulsed power generator, x-cut quartz crystals were subjected to shockless compression (loading rate of $∼3×105∕s$⁠). Plate impact experiments were used to subject samples to shock wave compression (loading rate $⩾4×107∕s$⁠). Particle velocity histories, measured at propagation distances of $1.5–3.5mm$⁠, demonstrated that the elastic limit of x-cut quartz under shockless compression was 85%–90% higher than the elastic limit under shock wave compression. The substantial increase in the elastic limit with decreasing loading rate is contrary to the expected loading rate dependence of material strength. Mechanistic implications of this finding are discussed.