为了实时得到低维材料的应变,提出了一种基于数字图像跟踪的低维材料实时应变测量方法。首先,将试件上制作的标志点或试件表面适当的特征点作为跟踪目标,采用改进的适于跟踪测量的图像相关公式,以及根据低维材料变形特点选取相应的匹配模板和搜索区域,实现了实时测量应变所需的两点跟踪;利用双线性插值算法将目标定位在0.01 pixel上的位置,提高了该方法的测量精度。然后分级施加荷载,不仅实时跟踪到目标,而且得到低维材料在相应载荷下的实时应变值,为研究低维材料动态力学特性提供了一种实验方法。通过实验,验证了数字图像跟踪技术完全可以应用于低维材料的实时应变测量,并且适用于不同距离标志点之间的测量,相对误差在5%以内。

In order to obtain the real-strain of low dimensional materials,the real-strain measurement of low-dimensional materials based on digital image tracking has been proposed. First,the speckles pre-made on the sample or its surface feature points are taken as the tracking objects. Two points are successfully tracked in the real-strain measurement by adopting the improved image correlation formula and selecting the correlative matched template and search region that are determined by analyzing the deformation characteristic of low-dimensional materials. By using the arithmetic of bilinear inter value,the objective is orientated in the 0.01 pixel location,so the measurement precision has been improved. Then,the loads are exerted at grade step. The objects can be successfully tracked. And,the real-strain value under the correlative loads has been obtained. Furthermore,it is an experiment method for studying the dynamic mechanics of low-dimensional materials. The experiment shows that the tracking technology can be fully applied in the real-strain measurement of low-dimension materials. Moreover,the method is also applied in the real-strain measurement of different distances between two speckles. And,the relative calculation error is controlled in 5%.