Advanced video extensometer for non-contact, real-time, high-accuracy strain measurement
Advanced video extensometer for non-contact, real-time, high-accuracy strain measurement
复制标题
先进的视频引伸计，用于非接触式、实时、高精度应变测量
DOI：
10.1364/oe.24.019082
复制
发表时间：
2016-08-22
期刊：
影响因子：
3.8
通讯作者：
Tian, Long
中科院分区：
文献类型：
--
作者：
Pan, Bing;Tian, Long
我们开发了一种先进的视频引伸计，用于材料测试中的非接触、实时、高精度应变测量。在所建立的视频引伸计中，结合主动成像的思想和高质量的双边远心透镜，构建了一个“接近完美和超稳定”的成像系统，以获得高保真的测试样品表面的视频图像，该图像不受环境光照变化和物体表面与图像平面之间发生的微小离面运动的影响。此外，一个有效的和准确的逆合成高斯-牛顿算法，结合时间初始猜测转移计划和高精度插值方法，以实现实时，高精度的位移跟踪与可忽略的偏差误差。对铝合金试样和碳纤维丝试样进行了拉伸试验，以验证所开发的先进视频引伸计的效率、重复性和准确性。结果表明，纵向和横向应变可以估计和绘制在117 fps的速率和最大应变误差小于30微应变。(C)2016美国光学学会
We developed an advanced video extensometer for non-contact, real-time, high-accuracy strain measurement in material testing. In the established video extensometer, a "near perfect and ultra-stable" imaging system, combining the idea of active imaging with a high-quality bilateral telecentric lens, is constructed to acquire high-fidelity video images of the test sample surface, which is invariant to ambient lighting changes and small out-of-plane motions occurred between the object surface and image plane. In addition, an efficient and accurate inverse compositional Gauss-Newton algorithm incorporating a temporal initial guess transfer scheme and a high-accuracy interpolation method is employed to achieve real-time, high-accuracy displacement tracking with negligible bias error. Tensile tests of an aluminum sample and a carbon fiber filament sample were performed to demonstrate the efficiency, repeatability and accuracy of the developed advanced video extensometer. The results indicate that longitudinal and transversal strains can be estimated and plotted at a rate of 117 fps and with a maximum strain error less than 30 microstrains. (C) 2016 Optical Society of America