体应变 VIC-Volume Digital Image Correlation Software

 

由CSI公司推出的全新Vic-Volume™软件是VIC数字图像相关产品线的一个令人兴奋的补充。 Vic-Volume利用来自X射线或CT扫描仪等断层扫描设备的体积图像来测量施加载荷下试件的内部变形。 Vic-Volume分析获取的图像,以创建试件内部行为的三维体积位移和应变数据。 得到的数据是变形数据的全场等值线图,可以查看,动画展示和提取做FEA验证。

The new Vic-Volume™ software by Correlated Solutions is an exciting addition to the VIC digital image correlation product line. Vic-Volume utilizes volumetric images from X-Rays or CT-Scanners to measure internal deformation of a specimen under an applied load. Vic-Volume analyzes the acquired images to create three-dimensional volumetric displacement and strain data of the specimen’s internal behavior. The resulting data is a full-field contour plot of the deformation data that can be viewed, animated, and extracted for FEA validation.

技术背景 Technology Background

 

数字图像相关技术(DIC)因其准确性,稳健性,多功能性,灵活性和整体易用性而广泛流行于全球的科学家,研究人员和工程师之中。 DIC通常使用白光机器视觉数码相机来进行二维和三维表面变形和应变测量。 自1998年以来,CSI公司提供了交钥匙方式的2D和3D DIC系统,并继续为其不断增长的产品线开发和添加新的先进DIC产品。 最近,CSI开发了新的软件,利用X射线或CT扫描仪的实用图像测量施加静态载荷下物体的体积变形(内应变)。

Digital Image Correlation (DIC) has found widespread popularity among scientists, researchers and engineers across the globe due to its accuracy, robustness, versatility, flexibility and overall ease of use. DIC is commonly used to measure 2D and 3D surface deformation and strain utilizing white light machine vision digital cameras. Correlated Solutions has offered turn-key 2D and 3D DIC systems since 1998, and continues to develop and add new advanced DIC products to our growing product line. More recently, Correlated Solutions has developed new software that utilities images from X-Rays or CT scanners to measure volumetric deformation of an object under an applied load.

 

测量设置 Setup

 

CT_inspection_line_detector

 

上图显示了在测试过程中如何采集图像的典型设置。 断层扫描仪获取特定深度坐标处的图像,然后Vic-Volume分析图像切片以构建由体素组成的3D体积。 各个体素是子卷的构建块,其中包含体积图像关联数据。

The diagram above displays a typical setup of how the images are acquired during a test. The scanner acquires images at specific depth coordinates, and then Vic-Volume analyzes the image slices to construct a 3D volume made up of voxels. The individual voxels are the building blocks for the sub-volume, which contain the volumetric image correlation data.

 

案例 Example 1

 

puck

橡胶圆盘安装在两个夹头之间,并以已知的增量从CT扫描仪获取一组参考图像。 然后分析每个“切片”数据以计算静态体积测量结果。 在圆盘经受压缩载荷后,CT扫描仪在相同位置再次获取图像。 DIC算法用于计算构成3D体积的每个单独体素处的体积变化或变形。

A rubber puck is mounted between two grips, and a set of reference images are acquired from a CT scanner at know increments. Each ‘slice’ of data is then analyzed to compute a static volume measurement. After the puck undergoes a compression load, images are acquired again by the CT scanner at the same locations. Digital Image Correlation algorithms are used to calculate the volumetric change or deformation at each individual voxel, which make up the 3D volume.

 

上面的动画显示了受压缩的橡胶圆盘的内部应变(Ezz)。 可以将体积应变(内应变)数据作为体积或单个数据切片进行查看,分析或提取。 通过该技术,内部压缩应变可以清楚地看到。

The above  animation displays the internal strain (Ezz) of a rubber puck undergoing compression.  The volumetric strain data can be viewed, analyzed, or extracted as a volume or as individual data slices. The internal compressive strain can clearly be seen.

 

案例 Example 2

RMC-pic

将增强的橡胶基质复合材料安装在两个手柄之间,并以已知增量的从CT扫描仪获取一组图像做参考。 然后分析每个“切片”数据以计算静态体积测量结果。 在标本经受拉伸载荷后,通过CT扫描仪在相同位置再次获取图像。 数字图像相关算法用于计算构成3D体积的每个单独体素处的体积变化或变形。

A reinforced rubber matrix composite is mounted between two grips, and a set of reference images are acquired from a CT scanner at know increments.  Each ‘slice’ of data is then analyzed to compute a static volume measurement.  After the specimen undergoes a tensile load, images are acquired again by the CT scanner at the same locations.  Digital Image Correlation algorithms are used to calculate the volumetric change or deformation at each individual voxel, which make up the 3D volume.

 

上述动画显示了经受张力的增强橡胶基质复合材料的内部应变(Ezz)。 可以将体积应变(内应变)数据作为体积或单个数据切片进行查看,分析或提取。 如视频所示,内部张力应变可以清楚地看到。

The above  animation displays the internal strain (Ezz) of a reinforced rubber matrix composite undergoing tension.  The volumetric strain data can be viewed, analyzed, or extracted as a volume or as individual data slices. The internal tension strain can clearly be seen.

 

技术特性 Vic-Volume Software Features

• 通过“Tweening”方法可方便的进行AOI选择
• 半自动化的初始预测计算
• 针对准确性进行了优化,可减少非线性优化以减少偏差和插值伪影
• 高度先进的内存管理允许分析巨大的体积数据集并提高计算效率
• 基于体积3D位移和应变信息

• Convenient AOI selection method through “Tweening’’
• Semi-automatic initial guess computation
• Optimized for accuracy reduce non-linear optimization to reduce bias and interpolation artifacts
• Highly Advanced memory management permits analysis of huge volumetric data sets
• Volumetric 3D displacements & strains