基于太赫兹光谱的平面应力测量方法

本文提出了一种基于太赫兹光谱技术的平面应力状态测量方法。该方法在传统的太赫兹时域光谱系统中引入起偏镜和检偏镜,实现了对太赫兹脉冲偏振态的调控。针对该实验系统,建立了试件所受应力与穿透试件的太赫兹波相位延迟之间的定量关系,并提出了根据实验所测太赫兹波相位延迟计算平面应力状态三个应力参量的数据处理方法。将该方法得到的实验结果和应变仪测量的结果作对比,发现两种方法有很好的一致性,证明此实验方法合理可靠。

Determination of Plane Stress State in Opaque Materials with THz Radiation

In this letter, a convenient experimental method is developed to determine the plane stress state of a stretched specimen. In this method, two polarizers are combined into the traditional terahertz time-domain spectroscopy (THz-TDS) system so that the polarization state of THz radiation can be modulated. With this system, the phase of detected THz radiation can be obtained, which contains the information of the applied stress. Based on the stress-optic law, an optimization algorithm is applied to an error function defined by us so that the plane stress state can be estimated from the phase information of the THz radiation. The measured stress components are compared to those acquired with strain gauges. Both of the results have a good agreement.