航空透明件表面波声弹效应

Surface wave acoustoelasticity of aerospace transparency

表面波作为超声波的一种特殊形式，由于其传播特性，使得通过改变频率检测距物体表面不同深度处的初始应力成为可能，因此，各种材料的表面波声弹理论与实验技术的研究不断受到重视。本文从弹性波和有限变形理论出发，推导了表面波在有初始应力的各向同性弹性体中传播时，物体表面应力与超声波传播速度之间的一般关系。对作为飞机坐舱的航空透明件YB－3有机玻璃试件进行了声弹性实验，同时还给出了由实验数据回归的三次多项式声弹公式。实验结果表明，此类材料中声表面波的传播速度对其中的应力的依赖关系只在很小的范围内是近似线性的，而在其强度极限内总体上为非线性关系。

Surface wave, as a special form of ultrasonic wave, makes it possible to probe initial stress at various depths below the surface by changing its frequency. In this paper the propagation of Rayleigh surface wave in an isotropic elastic material subjected to a homogenous stress is studied theoretically. The formula for the velocity change of surface wave versus the change in the applied static stress is investigated numerically.Acoustoelastic experiment for a specimen of aerospace transparency is also carried out.The result showes the nonlinear relation between sound velocity and applied stress.