数字光弹性中五步彩色相移法及其应用

把相移法与光学彩色信息图像处理技术相结合，提出全场数字化确定主方向角的光弹性五步彩色相移法。其主要优点是采用最简单的白光平面偏振仪光学系统，由数码照相机采集五幅等色线与等倾线相互耦合的彩色条纹图，经计算机进行处理后，就可以得到O～π／2]范围内单纯连续的等倾角相图；为了减少测量误差，在相移法中引入背景光强参与运算。对实验中存在的三种主要误差因素进行了定量分析，给出了具体的误差控制指标。用对径压缩圆盘问题的理论仿真模拟结果、基本实验和复杂平面及空间实际问题进行检验和对比，表明本方法是正确可行的。

Five-Step Color Phase-Shifting Technique in Digital Photoelasticity and Its Applications

Combined color imaging with phase shifting, a technique named five-step color phase shifting (CPST) is presented to determine principal direction angle and the whole-field single isoclinic phase map in the range of 0,π/2]. A digital camera recorded five isoclinic color images coupled with isochromatics from a plane polariscope with five different settings, respectively. The unloaded light intensity image is introduced to operation. For knowing the accuracy of the CPST influenced by the different error sources, such as measuring intensities errors, orientation errors, and especially the initial stress errors, methods are given to analyze and estimate the influence of the different error sources on the final calculated isoclinic results. Experiments have been carried out with the simulation of a circular disk under diametral compression and some actual applications. This technique utilizes white light, which avoids undefined isoclinics near the locations where the isochromatics exist, and will have active effect on experimental stress analysis and structural strength design.