数字光弹性法综述

A Review of Digital Photoelasticity

将光弹性法与计算机图像处理技术相结合 ,来自动采集光弹性数据和分析应力的方法 ,称为数字光弹性法 ,与传统光弹性法相比 ,它可以进一步提高实验速度和精度。本文详细讨论了以下两个方面 :一是光弹性条纹的细化和倍增处理技术 ;二是自动确定光弹性参数的技术 ,包括相移法、傅立叶变换法、逐步载荷法、广谱分析法和RGB光弹性法等。通过对近二十年来国内外在这些方面的研究、应用和进展作了综述 ,认为采用白光的彩色域相移技术计算光弹性等倾角 ,结合采用白光源或三色光源的相移法来确定光弹性等色线级数 ,有望成为解决静态二维和三维冻结模型薄切片应力分析的最佳方法 ;另外 ,设计一种能实时和同步采集多幅条纹图的实验装置 ,通过相移法来自动获取动态光弹性数据 。

Digital photoelasticity combined the traditional photoelasticity with computer imaging techniques in order to acquire photoelastic data and analysis stress automatically, can improve experimental speed and precision. In this paper, we firstly reviewed the photoelastic fringe refining and multiplication and the techniques for automatically determining photoelastic parameters, including phase shifting, Fourier transform method, load stepping, spectral content analysis and RGB photoelasticity etc. The advancements in the last two decades reveal that the combination of the isoclinic parameter, which is calculated by the color-field phase shifting technique, and the ischromatic parameter, which is determined by the phase shifting in white light or three-color light, is expected to solve the static stress analysis of two dimensional models or three dimensional thin slices. Moreover, the combination of designing a device to collect several photoelastic images real-timely or synchronously and acquiring photoelastic parameters by the phase shifting technique is one of the promising ways for the development of digital dynamic photoelasticity. The review also gives us a future trend of digital photoelasticity and benefits for automating data-acquisition and stress-analysis.