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Knowledgebase : Application Notes
Vic 2D Applications In order for a setup to be a good 2D application (with just one camera), the specimen must be: * Specimen must be flat * Specimen must be planar to camera sensor * No part of the specimen can have any out-of-plane motion towa...
By default, Vic-3D uses the "Best Plane Fit" to assign a coordinate system. This option calculates a transform into the best fit plane of the surface. Sometimes it is preferred to leave the data in camera coordinates. By deselecting the Auto Plane Fit o...
Users now have the ability to combine views from two 3D systems using only a rigid speckled target. This can be used in any case where data from two systems must be combined: * Facing systems, e..g, two sides of a tensile coupon for measuring thinning...
INTERPRETING 2D DIC DATA WHY DOES MY STRAIN OR DISPLACEMENT DATA NOT MATCH THEORY OR OTHER MEASURING TECHNIQUES?  INTRODUCTION Digital Image Correlation (DIC) data is often used as a validation method, so being able to compare DIC data to theory, FE...
INTERPRETING 3D DIC DATA WHY DOES MY STRAIN OR DISPLACEMENT DATA NOT MATCH THEORY OR OTHER MEASURING TECHNIQUES? INTRODUCTION Digital Image Correlation (DIC) data is often used as a validation method, so being able to compare DIC data to theory, ...
COMPUTING CYLINDRICAL TRANSFORMATIONS The cylindrical coordinates transformation in Vic-3D is used to orient the data in an appropriate orientation for looking at cylindrical data. This transformation allows you to view both your hoop and axial strain r...
CONSIDERATIONS FOR HIGH-MAGNIFICATION TESTS Some of the most useful results in Digital Image Correlation come from high-magnification, small field of view tests. At the same time, these tests can be increasingly difficult, depending on the magnification....
Because of how we track and match images in order to obtain data, and because of the fundamentals of strain theory, we must treat the area of interest as a continuous surface. Discontinuous surfaces can result in unreliable data and erroneous strains. T...
This application note explains how to merge data from several systems encircling a cylinder. http://www.correlatedsolutions.com/supportcontent/cylinder-data-stitching.pdf [http://www.correlatedsolutions.com/supportcontent/cylinder-data-stitching.pdf]
There are several instances in which the use of the External Orientation Calibration can be helpful: 1. Large measurement fields for which a large enough grid is not practical. 2. The cameras have been moved or bumped since calibration, giving you a h...
Vic-Snap automatically names the images with the correct naming conventions for Vic-3D. So other than remembering not to use and underscore in the filename, there is no actions necessary for naming files correctly when using Vic-Snap. When using acquisi...
This application note covers the procedure for combining FLIR temperature data with 3D correlation fields, as well as the basics of using a FLIR camera with Vic-Snap. Related sample data can be found here [http://www.correlatedsolutions.com/installs/IR-ex...
We offer many different cameras, but in general theses are some things to check if your cameras aren't coming up: 1. Did anything change since they were last working (software settings, upgrading, etc.). If not, it is a hardware issue. 2. Check each c...
OVERVIEW When heat sources or hot surfaces are present in a DIC testing setup, refractive heat waves may distort your image; this distortion is not always apparent but it can create major errors in your results. These heat waves are similar to the heat ...
Calibrating for a high magnification setup can present a few challenges. This article will discuss techniques for getting the best calibration result at small fields of view. WHAT IS 'HIGH MAGNIFICATION'? A high magnification test is one where the lens...
The VicPy Python module for manipulating Vic-3D data is now available. For consistency and ease of installation, we are using the Anaconda(R) platform. TO INSTALL VICPY: * Download Anaconda from this link: https://www.continuum.io/downloads#windows [...
In Vic-2D and Vic-3D, some of the inspector tools will cause data to be averaged over a certain area - specifically, the Disc and Rectangle tools. With these tools, when the data is extracted, the resulting values will be a mass average of the values with...
Generally speaking, there are not many rules to setting up cameras, such as the stereo angle between cameras and lens selection because the calibration calculates all the parameters, such as stereo angle and focal length. However there are a few things to...
The following article gives an overview of merging data from multiple stereo systems: http://www.correlatedsolutions.com/supportcontent/merging-multiple-systems.pdf [http://www.correlatedsolutions.com/supportcontent/merging-multiple-systems.pdf]
Practices and Procedures to minimize error/noise and eliminate bias in your DIC data: http://www.correlatedsolutions.com/supportcontent/dic-noise-bias.pdf [http://www.correlatedsolutions.com/supportcontent/dic-noise-bias.pdf]
Navitar lens systems allow for a 6.5x magnification. The lens systems include many parts (C-mount coupler, adapters, zoom lenses, lens attachments, extenders, etc.) Linked below are flowcharts and exploded view for the following lens systems: ZOOM 6000 ...
Obtaining Synchronized Data Most of our systems come with an National Instruments DAQ. Typically these have BNC Inputs. Once the DAQ is plugged in, the Analog Data icon in Vic-Snap will no longer be greyed out. If it still is greyed out after the DAQ is...
During correlation and optional post-processing, Vic presents a wide range of output data available for 3D and contour plotting, extraction, and export. This application note gives an overview of commonly presented variables. OUTPUT VARIABLES Always P...
Sometimes, images acquired for use in 2D or 3D digital image correlation tests can be too dark; noisy; blurry; or aliased. From time to time we are asked whether it would be beneficial to process these images in software such as Photoshop to fix these iss...
INTRODUCTION When running a correlation in Vic-3D, one of the values given for each image is the _Projection error_. This article will explain how the projection error is calculated and what can cause a high projection error. Based on the calibration, ...
TEMPLATE TAG REFERENCE BASICS To insert a text tag, place the tag and any parameters, separated by commas, inside braces. The tag will be replaced by the appropriate value without changing the font, position, etc. For example, {@VIC_RIG_TX}. To insert ...
SYSTEM SPECS Many things in our test set-up can affect our noise and resolution, but with a good setup, the following rules of thumb can be applied to estimate what type of noise and resolution you can expect out of your test. This is what we base most ...
TO MAKE PYTHON SCRIPTS RUNNABLE FROM ANY LOCATION UNDER WINDOWS: To call python scripts directly from the anaconda console command prompt, e.g., to invoke the script "foo.py" by typing: > foo.py instead of needing to type: > python pathtofoo.py P...
The linked PDF details the procedure for correcting SEM drift and distortion in Vic-2D. The ZIP file contains a demo set of distortion correction data together with an image list. SEM Drift Correction [http://www.correlatedsolutions.com/supportcontent/s...
The linked note describes the procedure for setting up and troubleshooting the Vic-Snap remote app as well as details on using the supplied D-Link DIR-505L. http://www.correlatedsolutions.com/supportcontent/vic-snap-remote-setup.pdf [http://www.correlat...
SPECKLE PATTERN FUNDAMENTALS In digital image correlation, there is the quality of the data is often dependent on the quality of the speckle pattern. Using an optimal speckle pattern is one of the most important factors in reducing measurement noise and...
A quick graphical explanation of how deformations are converted to strains in Vic-3D: http://www.correlatedsolutions.com/supportcontent/strain.pdf [http://www.correlatedsolutions.com/supportcontent/strain.pdf]
Strain filters in Vic-2D and Vic-3D are user-defined so that users can select how localized or how averaged the strains will be presented in the data. The strain filter helps determine the strain gauge size for all of the individual points on the contour ...
STRAIN TENSORS  When comparing strain values obtained from DIC to analytical results or to strain results obtained from other measurement methods, it's important to select the strain tensor which matches your expected values. At low strains, many of thes...
SUMMARY AND OVERVIEW Here we will discuss subset size, step size and strain filter selection. In short, you want your subset to be larger than your speckle sizes and for most applications your step size to be roughly 1/4 of the subset size. As a rule of ...
WHAT YOUR SYSTEM INCLUDES: Turn-key DIC systems include a minimum of a year of support and upgrades (some systems include longer service contracts). This contract can be extended at anytime. Check with us, or check your purchase order to see when your u...
An overview and setup guide of the triggering methods including Digital Pulse(or TTL Capture) and Hardware Triggering, used to obtain synchronized data during the acquisition process, available through Vic-Snap.
Calibration in Vic-3D is well automated but certain situations can lead to problems with either high calibration scores, or a failure to calibrate at all. This article lists some common causes for each situation. WHAT IS THE CALIBRATION SCORE? Calibrat...
The linked PDF contains a few quick tips about setting up and using network license keys: http://www.correlatedsolutions.com/supportcontent/using-network-keys.pdf [http://www.correlatedsolutions.com/supportcontent/using-network-keys.pdf] The network-a...
The linked article discusses the details of testing with Photron (TM) cameras. http://www.correlatedsolutions.com/supportcontent/photron-camera-notes.pdf [http://www.correlatedsolutions.com/supportcontent/photron-camera-notes.pdf]
The linked article covers vibration and rotary measurements using the vibration module in Vic-Snap. http://www.correlatedsolutions.com/supportcontent/vibration-overview.pdf [http://www.correlatedsolutions.com/supportcontent/vibration-overview.pdf]
This feature was previously labeled "Show co-variance" and then "Show sigma estimate." The "Show Focus/Contrast" feature may be selected by right clicking the live image in Vic-Snap. The user is also given the option for three different subset sizes in...
Most Vic Turn-key systems come with two types of keys: 1. The acquisition license, which is located inside the PC and enables Vic-Snap (possibly Vic-Gauge, if purchased), Vic-2D, and Vic-3D (if purchased). 2. The post processing dongle (sometimes more...
The online documentation for the VicPy Python module can be found at: http://www.correlatedsolutions.com/supportcontent/VicPy/ [http://www.correlatedsolutions.com/supportcontent/VicPy/]
Particularly common with high heat applications, sometimes we must view through a window, glass, viewing pane. There are just a few things to keep in mind when doing this: 1. Keep the window as planar to the sensor planes as possible. Sometimes the ca...
The X, Y and Z values in exported data are the undeformed X, Y and Z values, which do not change. These are the same X, Y and Z values displayed on the contour graph when "Show reference data" is selected. However, in contour graphs "show deformed data" i...