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条纹灰度法在光弹性中能自动采集数据、分析和显示等色线条纹图。这种方法组合了光弹性和数字图象分析两种技术,这篇论文描述了一个Apple—Ⅱ微型计算机图象分析系统,它把等色线图分成256×256个图象元素(象素),每一象素将亮度转换成8—bit分辨率的视频讯号,在黑到亮之间产生256级灰度,灰度Z与条纹级数N在暗场时,它能写成N=(1/π)arcsin(AZ~(1/2r))其中A、r是常数。这种方法对相对迟后小于半波长的双折射特别有效,这篇论文中用两片玻璃模型研究弹性应力场,具有很好的分辨率,其结果表明对应力分析主应力差(σ_1-σ_2)有较高精度。
Stripe grayscale in the photoelastic can automatically collect data, analysis and display contour lines such as color stripes. This method combines two technologies, photoelasticity and digital image analysis. This paper describes an Apple-II microcomputer image analysis system that divides the isochromatic line into 256 × 256 image elements (pixels) , Each pixel converts the brightness into an 8-bit resolution video signal, producing 256 levels of gray between black and bright, and grayscale Z and the number of fringes N in the dark field can be written as N = (1 / π) arcsin (AZ ~ (1 / 2r)) where A, r are constants. This method is particularly effective for birefringence of less than half-wavelength later. In this paper, two glass models are used to study the elastic stress field and have good resolution. The results show that the principal stress difference (σ_1 -σ_2 ) Have higher precision.