FULL-FIELD REPRESENTATION OF DISCRETELY SAMPLED SURFACE DEFORMATION FOR DISPLACEMENT AND STRAIN ANALYSIS
FULL-FIELD REPRESENTATION OF DISCRETELY SAMPLED SURFACE DEFORMATION FOR DISPLACEMENT AND STRAIN ANALYSIS
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DOI：
10.1007/bf02327571
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发表时间：
1991-06-01
影响因子：
2.4
通讯作者：
CHAE, TA
中科院分区：
文献类型：
--
作者：
SUTTON, MA;TURNER, JL;CHAE, TA
详细评估的可行性，确定从测量的表面位移场的位移和位移梯度。 提出了一种改进的噪声估计和消除方法。 该方法用于分析三种试验的梯度：（1）均匀旋转，（2）均匀应变，（3）裂纹尖端位移场。 研究结果表明，所提出的方法可以用来提取潜在的二维位移和相应的梯度噪声数据具有合理的精度。 具体地，示出了（a）用于获取位移场的数字相关方法在每个点处具有大约150 μ应变的应变误差，（B）均匀应变区域中的平均应变具有小得多的误差，通常在20 μ应变的量级，（c）数字相关中存在的位移“噪声”非常小，大约0.01像素，（d）减少数据中噪音的拟议方法对准确评估位移梯度至关重要，（e）对所有三种情况的位移和位移梯度的成功评估表明，拟议方法既可用于量化位移场，也可用于合理估计总的梯度趋势。
A detailed evaluation of the feasibility of determining displacements and displacement gradients from measured surface displacement fields is presented. An improved methodology for both the estimation and elimination of noise is proposed. The methodology is used to analyze the gradients for three tests: (1) uniform rotation, (2) uniform strain, and (3) crack-tip displacement fields. Results of the study indicate that the proposed methodology can be used to extract the underlying two-dimensional displacements and their corresponding gradients from the noisy data with reasonable accuracy. Specifically, it is shown that (a) the digital correlation method for acquiring displacement fields has an error in strain of approximately 150-mu-strain at each point, (b) the average strain in a region of uniform strain has much less error, typically on the order of 20-mu-strain, (c) the displacement 'noise' present in digital correlation is very small, approximately 0.01 pixels, (d) the proposed methodology for reducing noise in the data is essential to the accurate evaluation of displacement gradients and (e) the successful evaluation of displacement and displacement gradients for all three cases indicates that the proposed methodology can be used both to quantify the displacement fields and to reasonably estimate the overall gradient trends.