基于数字图像的非接触式泊松比测试方法

针对胶结充填材料等采用传统粘贴应变片测量泊松比方法出现的无法测量或测量精度不高的问题,提出了基于数字图像相关技术的非接触式泊松比测试方法,并阐述了该测试方法的原理与测试过程。运用Vic-2D软件对CCD相机所拍摄的胶结充填试块在加载系统作用下变形破坏过程的数字图像进行计算分析,得到了全场位移变化云图。选取试块弹性范围内图片,利用测线取点功能对试块两侧和上部取点分析,计算水平位移与垂直位移。对胶结充填材料泊松比测试结果表明,养护龄期相同的同组试块泊松比相近;养护龄期不同的各组试块,随养护龄期的增加,泊松比从0.378减小到0.103。该实验的成功应用证明了非接触式泊松比测试方法的可操作性、准确性与可靠性。

Non-contact testing method for Poisson ratio based on digital image

A new testing method was put forward to the problems of immeasurability or low measuring precision in the processes of Poisson ratio measuring for cemented filling materials etc by pasting strain gauge，which was based on digital image correlation technique.The authors described principle and process of Poisson ratio testing method.The digital images shot in the deformation process of cemented filling test block under the action of loading system with CCD camera were analyzed with software of Vic-2D to get full displacement changes cloud picture.The authors choose the pictures within test block’ elastic stage，and got the points of the free sides to calculate test horizontal displacement and vertical displacement of block.Cemented filling material Poisson ratio testing results show that the test blocks with same curing time had approximate Poisson ratio;for the test blocks with different curing time，the Poisson ratio is smaller with the increase of curing time from 0.378 to 0.103.The successful application of the experiment prove the non-contact Poisson ratio testing method of maneuverability，veracity and reliability.