In this application video, a 2-cam 2.3 Mpx EduDIC system is used to measure the engineering effective
(von Mises) strain, total displacement (with Rigid Body Motion Removed) and engineering shear strain XY
of a diamond cut-out 3D-printed Coupon in the new Istra4D V4.13 software.
New features from the Istra4D V4.13 software presented in this application video include;
- Image Rotation, in each camera view by +90° intervals
- New HDF5 Image Compression Options, allowing faster saving of data or smaller data sets to be acquired
- Smart Colorbars, in each camera visualization new colour bars and colour step-levels can be quantified
- Guage Plate Data Labelling, allowing freely definable plates to be added anywhere in a visualization
with any active (visualized) or static data values for either the entire grid or virtual gauge data.In the live setup mode, the acquisition frame rate of the cameras operating in Master/Slave mode is set
to 162 fps.
The Region-of-Interest (RoI) is adjusted in the horizontal resolution direction. In each camera view, the RoI
can be shifted to the middle of each camera image. Image rotation, in Istra4D 4.13, is changed through
selection of the +90° rotation intervals from the User Toolbar. Each camera view can be independently
changed, in every phase within the measurement process (live setup, projection calibration, meas.
series playback, correlation evaluation, and graphical visualization).
In the projection calibration, the QR-code of the 10mm Calibration Target is recognized and detected
automatically via Istra4D. Each calibration target has its own encrypted QR-code which states the
calibration target’s inherit ID and properties. During the online calibration, the projection calibration model
is computed and updated with a live feedback status.
The automatic recording procedure is then selected for the measurement and is stopped manually be the
user following the specimen fracture. New HDF5 Image Compression Options, in Istra4D V4.13, allow users
to save the images in different compressed or even uncompressed formats for either speed or data space.
Selection of “No Compression”, for example, is 6x faster than the default compression format “Zlib”, as such,
using 2x 2.3 Mpx cameras the automatic recording procedure can operate & save image at a full rate of 80 fps.
However in the application video, every 10th image is saved at the operational acquisition rate at 162 fps
(meaning 16 frames are being saved every second)
The correlation evaluation was not presented or shown in this application video.
In the graphical visualization, the 2D-overlay of the effective (von Mises) strain can be seen. The von Mises
strain, also known as equivalent plastic strain or effective strain, is a single scalar value used to measure total
permanent shape change in a ductile material under complex loads. In this measurement the maximum effective
strain is 90 mstrain. Thenafter the total displacement with rigid body motion removed (RBMR) is selected showing
the generation and concentration of strain around the diamond cut-out and the location where the sample eventually
fractures. Smart Colorbars, in Istra4D V4.13, can be seen whereby for the selected camera view visualization, a
different palette is selected for each camera. A ”plasma” colour map is selected, proving another palette for better
visualization. The quantification of the colour levels for the “plasma” colour map is reduced to 8-levels given better
indication of the strain concentration. The new Gauge Plate Data Labelling feature in Istra4D V4.13 is also presented,
whereby a plate is created for which data can be freely added, either from data within the entire evaluated grid or that
from virtual gauges. Additionally, the active quantity of the selected visualization display can also be added to any plate.
Finally, temporal plots are made of a virtual line and circle gauge, showing the Euclidean length change of the line gauge
(in mm) in the upper plot and the engineering line strain of the line gauge (in mstrain) with the maximum shear strain XY
across the surface of the circle gauge (in mstrain).
Tensile Test of a Diamond Cut-Out Coupon using Istra4D V4.13
To learn more about how Dantec Dynamics can help you solve your testing challenges, contact us today.
