熔石英的四阶弹性常数

根据Ｍｕｒｎａｇｈａｎ的有限形变理论和Ｗａｌｌａｃｅ的预应力固体热弹性理论，导出了在流体静压力和单轴应力下立方对称或各向同性固体中小振幅弹性波传播速度与二、三、四阶弹性常数间的非线性应力关系式．用脉冲超声回波重合技术，在０．１至７００ＭＰａ的压力范围，对不同的预应力和波的传播条件，测量了熔石英中超声纵波和横波自然声速值随压力的变化，由实验结果确定了熔石英全部独立的四阶弹性常数．

Fourth-Order Elastic Constants of Fused Quartz

Based on the finite strain formula of Murnaghan and the thermoelastic theory for Stressed materials of Wallace,the nonlinear stress expressions of the propagation velocitics of small amplitute elastic waves in a cubic symmetric or isotropic solid subjeCted to a hydrostatic pressure or an uniaxial stress are derived in terms of sectond,third and fourth cider elastic constants at zero stress. By using the technique of ultrasonic Pulse-echo overlap,the pressure variations of natural sound velOCity in fused quartz are measured in the range of pressure up to 700MPa for the different elastic modes. Combining these experimental results,all independent fourth cider elastic constants have ben evaluated