BCTF-50 – Backlit Calibration Target Fixture

The BCTF-50 – Designed for glass calibration targets

BCTF-50 Technical Features

  • Battery powered backlight illumination
  • 6h run time / 1h charge via Micro USB
  • Adapter for microscope targets
  • Rotational axis for tilting in grid centre
  • Shifting via x-y-z stage
  • Tensile testing machine clamp adapter
  • Target exchange via clip fixture
  • For max. target size of 50 x 50 mm
  • available with different clamping adapters for flat or round specimens (see below)

            

For further information, a quotation or in case of any questions, please don’t hesitate to contact us via info@correlatedsolutions.eu

Speckle Pattern Application Kit

The Speckle Pattern Application Kit for the easy and fast production of a perfect speckle pattern for your DIC application!

The correlated solutions speckle components provide the production of ideal speckle pattern which is important for good signatures throughout the area of interest so that consistent sized subsets may be tracked with certainty

 

 

Characteristics and advantages:

  • High contrast, quick preparation
  • Precision: Optimised and consistent dot sizes
  • 50 % coverage: equal amount of black and white
  • Random: Perfect mixture between irregular and regular pattern
  • Result: improved higher spatial resolution due to optimised subset size and highly reduced noise

 

Why a good speckle patter is required?

In DIC, a mesh of small subsets of the image are tracked as the specimen moves and deforms. To perform this tracking, the subsets are shifted until the pattern in the deformed image matches the reference image as closely as possible; this match is calculated by the total difference in grey levels at each point. A good pattern will allow the correlation to be made with high confidence and produce low noise. The example below shows the uncertainty for the out of plane measurement data in Z-direction with different speckle patterns.

 

 

In order to provide consistent speckle patterns for various sample sizes and materials, the speckle kit includes:

 

Stamp Rollers (6 sizes):

  • 0,18mm dot size for 53 – 145mm FOV*
  • 0,33mm dot size for 102 – 296mm FOV*
  • 0,66mm dot size for 203 – 539mm FOV*
  • 1,27mm dot size for 389 – 826mm FOV*
  • 2,45mm dot size for 762 – 2032 mm FOV*
  • 5,08mm dot size for 1524 – 4064 mm FOV*

Flat Stamp Rockers 146 x 146mm (6 sizes)

  • 0,18mm dot size for 53 – 145mm FOV*
  • 0,33mm dot size for 102 – 296mm FOV*
  • 0,66mm dot size for 203 – 539mm FOV*
  • 1,27mm dot size for 389 – 826mm FOV*
  • 2,45mm dot size for 762 – 2032 mm FOV*
  • 5,08mm dot size for 1524 – 4064 mm FOV*
  • Rocker for Flat Stamps

Accessories:

  • extra ink
  • ink pad
  • hard padded carrying case

 

* recommended FOV (image width) for standard 5Mpx sensor with 2500x2000px. Alternatively check dot size, which should be minimum about 3x3px.

 

For further information, a quotation or in case of any questions, please don’t hesitate to contact us via info@correlatedsolutions.eu

Polarization filter for HEDLER LED

NEW! The new polarization filter for HEDLER LED

The major reason for applying light forming equipment in DIC is to avoid direct reflections. The HEDLER Profilux LEDs can be equipped with different light forming accessories such as usually applied in conventional photo studios. Some of them are also suitable for DIC. Correlated Solutions Europe can recommend suitable accessories for your application.

However the first basic recommendation is to set up the light source independently from the DIC system to adjust a suitable illumination direction. In a number of applications this is sufficient and these accessories can be avoided, which is of advantage, because their application is combined with light losses.

A highly recommended item is the new polarization filter especially developed for the high power Hedler LED 1000, which helps to work on strongly curved and shiny – even wet – surfaces, when combined with suitable polarisation filters on the DIC stereo system

HEDLER LED light sources

isi-sys offers various light sources from Hedler, in particular the following products, for which we also offer a polarization filter specially developed by us (read more>>):

 

LED1000

Focusable white LED light source with 185W, continuous wave

 

 

The HEDLER Profilux LED1000 is a new developed continuous light unit which generates with one high power single LED daylight quality with approx. 5600K and a CRI > 90 – flicker-free! It has an extremely quiet fan cooling and a special, active LED cooling; the LED has an average lifetime of approx. 50000 hours.

It comes with:

  • Fresnel lens
  • 185 Watts high power single cell LED
  • Integrated Electronic Ballast
  • U-bracket with 5/8″ quick-lock light stand attachment and friction brake plus the HEDLER QuickFit adapter for comfortable and fast interchanging of reflectors.

 

 

LED 650

70° expanded white LED light source with 75W continuous wave

 

 

LED 1000x

75°expanded white light source with 185W continuous wave

 

Note: The LED 650 and 1000x are only recommended for large FOV >1m applications at short object distances for cost reasons. Operation with separate light stand or tripod recommended, as without focusing such as for LED 1000.

Blue-X-Focus – LED light source

The new LED light source with 200W @ 100Hz and 1μs flash period

The Blue-X-Focus is a powerful LED light source, especially designed by isi-sys for digital image correlation:

  • The short, single wave length (blue) improves the optical transfer function properties especially a) at the image boarders for conventional lenses and b) for high resolution, small FOV set-ups such as the Micro 3D stereo sensor.
  • The pulse mode reduces motion blur and maximizes light power at lowest possible heating of the object surface
  • Large beam expansion range from 3,2° to 60° for small to large field of view. Operation through small windows
  • A polarization-filter (optional) is suppressing direct reflections in combination with a second pair for the sensors
  • The short wavelength can be used in combination with bandpass filters for measuring on hot samples

Further details:

  • Power: Standard operation with 80W in continuous mode or 120W for pulse mode depending on duty cycle. Example for 0,7 duty cycle: 105W @ 240Hz and 2,9ms flash period. Power adjustable manually or external by pulse length and frequency as well as automatically limited depending on temperature.
  • The focusing adapter for standard DIC is from 5° to 60° expansion. The version for small FOV is adjustable from 3,2° to 4,7° expansion corresponding to e. g. 5mm x 3mm at 53mm WD or 300mm x 140mm at 1800mm WD (working distance)
  • Mounting is possible horizontal or vertical via M6 or ¼” threads
  • The cooling air stream is directed from the front inlet to the backside to avoid hot air waves in the images.Power: Standard operation with 80W in continuous mode or 120W for pulse mode depending on duty cycle. Example for 0,7 duty cycle: 105W @ 240Hz and 2,9ms flash period.

Application example for DIC on small FOV (magnification 1:1 approx. 14x10mm @ 12Mpx, Rodagon 135mm)

DAQ Devices

The isi-sys DAQ devices are set up for operation with the Vic software for Digital Image Correlation (DIC) by Correlated Solutions and function as integral part of isi-sys turn-key DIC systems. They mainly serve for triggering the cameras (hardware trigger) and simultaneously recording analog data as well as for delivering analogue real-time output generated by the Vic-Gauge software.

There are three DAQ types with different performance and features (and pricing):

 

DAQ-STD-8D

Only the DAQ-STD- 8D Synchronization- / Trigger Device can be used for synchronization of the cameras via a periodic signal (supported by the Fulcrum Module of Vic-Snap or the isi-sys synchronisation software module / isi-Studio

 

 

 

 

 

DAQ-T8D-16

 

Isi-sys also offers a 16-bit device – the DAQ-T8D-16. Both devices have +/-10V output channels.

 

 

 

 

 

 

DIC-DAQ-Box-klein
The DAQ-T4D-12 is a 12bit device with 5V analog output

 

 

 

 

 

 

 

Camera Trigger & Power supply

Hardware triggering and the power supply for the cameras are transmitted via the 12-pin Hirose connectors on the DAQ device. Two of these connectors are available for connecting up to two cameras. Isi-sys also offers Y-cables for operating 4 cameras (two stereo systems) or more. It is also possible to operate more than two cameras with one DAQ device. We will be happy to advise you.

 

Computer Connection 

Connection to a computer is done by USB cable (type A <-> type B connector).

 

Analog inputs

isi-sys DAQ devices are available with either differential or non-differential analog inputs. The analog input connectors are BNC type, the range is +/-10V.

 

Further IO connectors

Besides analog inputs, all isi-sys DAQ devices can also be equipped with analog outputs (BNC type connector), which differ in voltage range depending on DAQ type. Digital IO connectors (BNC type) are available as well.

Vic-3D Educational System

The new VIC-3D Educational (EDU) System from Correlated Solutions is a low-cost solution developed for academic institutions to assist in teaching the Digital Image Correlation technique to undergraduate and graduate students.

The VIC-3D EDU system utilizes the same accurate DIC algorithms found in the powerful VIC-3D software, while allowing users to acquire data quickly and easily. The system features a simplified setup, streamlined image acquisition, and ideal post-processing features. The stereo cameras are mounted inside a protective enclosure, which includes an integrated LED light source, a cooling fan, and an exterior USB & power connectors. The system also includes a tripod, tripod head, speckle roller, ink pad, calibration target, and a convenient carrying case.

This product is the perfect addition to engineering courses such as solid mechanics, measurements, structures, automotive design, aerospace, safety, FEA validation, and many others. Furthermore, the VIC-3D EDU software has the ability to process images acquired from any VIC-3D EDU system, which allows users to share images not only across campus, but also with colleagues at other universities. The system simply requires a computer with one available USB3 port and one available power source. Whether you are teaching students new measurement techniques or validating FEA models, this system will surely enhance the quality of your department’s curriculum.

 

 

VIC-3D Educational System

 

 

VIC-3D Educational System specifications:

 

Camera Resolution 1920 x 1200 (2.3 Megapixels)
Frame Rate 20Hz live, .5Hz acquisition, 100 frames per capture
Exposure Time 19µs – 1s
Field of View Fixed: 150 x 200mm
Displacement Resolution In-plane: +/-2µm; Out-of-plane: +/-4µm
Strain Measurement Resolution 50µε
Strain Measurement Range  0.005% to >2000%
VIC-3D EDU Licenses Unlimited
Software Features 3D displacements, strains, graphing tools, and much more

 

For more information or a quotation please don’t hesitate to contact us on info@correlatedsolutions.eu  or via phone: +49 561 739798-0.

3D-Micro-DIC

The Strainograph-3D camera (SG-3D) is used for full-field strain, deformation, and fatigue measurements on small field of view with high resolution (5Mpx) or as 3D Video-Extensometer (up to 500Hz). The measurement principle is digital image correlation based on the world wide established VICTM software (VicSnap, Vic-3D and Vic-Gauge) of Correlated-Solutions. The isi-sys sensor hardware and Vic-software are fusing to a practical high end device for quick and reliable operation in material testing and structural analysis.

Advantages and features of  the SG-3D system:

  • Compact and rigid design, quick set-up and easy handling
  • Pre-adjusted, fixed field of view and stable calibration
  • Specially designed for small and very small field of view (FOV)
  • Reliable and fast USB 3.0 interface for Desktop or Laptop PCs
  • Turn-key solution including Vic-Snap and Vic-Gauge 3
  • DRobust and reliable post-processing with Vic-3D

strainograph-test-sample

strainograph-diagram

Technical highlights of Strainograph SG-3D

  • 3D full field (5Mpx@75Hz frame rate) continuously recording on SSD
  • Higher framerates at reduced resolution
    (e. g. [Pixel@Hz]: 1600×1200@133; 1920×1080@148; 1280×720@217; 800×600@258; 640×480@315; 320×240@576).
  • suitable for Video-Extensometer functions and real time feedback control
  • Strain noise level of ±0,001% (±10µstrain) and better by time averaging
  • Deformation sensitivity in nm range (1/100 pixel) depending on FOV

 

Available measurement volume versions [mm]

height width depth
4,2 3,5 0,16
5,6 4,7 0,23
8,4 7,0 0,40
11,3 9,4 0,63
16,9 14,1 1,27
25,4 21,2 2,50

Data acquisition units (DAQ) for SG-3D

strainograph-daq2

  • Image synchronised analogue data recording (8x differential mode,16 bit, ±10V)
  • 2 x analogue output channels for feedback control (16 bit, ±10V)
  • Camera triggering and (optional) phase synchronisation for periodic signals
  • Fully integrated and supported by all VIC TM software modules

Principle of Digital Image Correlation

Digital Image Correlation (often referred to as “DIC”) is an easy to use proven optical method to measure deformation on an object surface. The method tracks the gray value pattern in small neighborhoods called subsets (indicated in red in the figure below) during deformation. Digital Image Correlation has been proven over and over to be accurate when compared to valid FEA models. The commercially available VIC-2D and VIC-3D systems from Correlated Solutions both utilize this advanced optical measurement technology.

 

Digital Image Correlation Overview

Below are the reasons why its versatility, robustness, and ease of use make it the only choice when it comes to digital image correlation.

DIC - Principle of Digital Image Correlation

Two-dimensional Example

In the two pictures below you can see a speckle pattern on an aluminum sample with two offset semi-circular cut-outs. The two pictures were taken from an animation with the left image taken from the beginning and the right picture taken from the end of the animation. Since the deformation is predominantly in-plane, a single camera can be used to measure the deformation.

VIC2D

Small Deformation

VIC2Da

Large Deformation

The pictures below show the horizontal strain measured by two-dimensional image correlation for the pictures shown above.

VIC2D-2 VIC2D-2a
VIC2D-2b


Three-dimensional Example

These two speckle images below were taken simultaneously with the left and right camera of a stereo-system. The sample itself is a piece of glass with the company logo sticker adhered to the surface.  The speckle pattern was applied using standard off-the-shelf flat white and black spray paint.  Can you make out the shape?

VIC3Dleft

Left View
VIC3Dright

Right View

In the plot below the shape of the logo sticker measured with the VIC-3D System is shown. The thickness of the logo sticker is approximately 0.003″ or 0.070mm.

VIC3D-2
For more infomation have a look at our DIC products or contact us via info@correlatedsolutions.eu or +49 561 – 739798-0

Combination of Digital Image Correlation and Thermography

Thermography is based on the principle that induced heat in mechanical components causes a different temperature field in the area of defects or inhomogeneities. The digital image correlation is a powerful system for measuring and visualizing strain, deformation and 3D surface shape.

The VIC-3D IR System features an infrared (IR) camera that is integrated with the DIC cameras enabling temperature data to be accurately acquired and analyzed with the full-field strain and deformation data. The system works by first calibrating the intrinsic optical parameters of the IR camera and then calibrating the position of the IR camera relative to the stereo DIC system. This triangulation allows VIC-3D to place the thermal and strain (or deformation) as well as 3D surface data into a common coordinate system.

The calibration procedure has been streamlined by integrating the IR camera into our VIC-Snap image acquisition software, which allows the user to capture images from the IR and DIC cameras simultaneously. The result is an easy to use turn-key thermal imaging system that utilizes digital image correlation to accurately measure temperature and strain concurrently without any contact with the sample. Thermal and strain data can be viewed, analyzed, and extracted over the entire field or at precise locations.

The system is sold as a turn-key solution which includes all software, hardware, onsite installation, and one year of unlimited technical support and software upgrades giving you piece of  mind that your system functions as intended, so you can start acquiring data immediately. This unique thermal integration capability may also be added to any existing VIC-3D system for increased functionality.

System Configuration and Features

Both the IR camera for thermography and the two CCD cameras for 3D image correlation are mounted on a standard stereo bar.

  • Temperatures up to 2,000C
  • Synchronized IR and DIC images
  • User-friendly setup and calibration
  • Uniquely designed IR calibration targets
  • Analog data synchronization
  • Extract points, regions, or node locations for FEA validation
  • Accurately measure deformation and thermal data concurrently
  • Remotely view and acquire images using the Vic-Snap remote
  • Measure 3D full-field displacements and strains
  • All the features for the VIC-3D system included

Advantages of this multi-function device are all applications with component deformations caused by thermal energy like current flow. This product allows a simultaneously determination of the heat flows as well as strain and deformation.

Example 1: Photovoltaic Module

Defective photovoltaic modules have been measured during operation over several minutes.  A preparation with speckle pattern is necessary for digital image correlation (here the backside of the panel). The marked areas are heated up due to electric/mechanical errors during operation.

Principal strain (epsilon 1) over time (index) of the points C0, C1, C2 shown in the image below. Following three dimensional presentation of the temperature values.

Three dimensional graph of the conture, superposed with the measured temperature (colour scale).

Three dimensional graph fo the conture, superposed with the strain measurement (colour scale).

Example 2: Analysis of simultaneous one-sided heating and compressive loading on an e-glass/vinyl ester/ balsa wood sandwich composite sample

Understanding thermo-mechanical behavior of material can be a vital component when designing vehicles  and structures that may become exposed to high temperatures. Virginia Tech’s Extreme Environments, Robotics, and Materials (ExtReMe) Laboratory focuses on the impact of extreme environments on materials. This includes research that is focused on understanding the thermo-mechanical behavior of materials both during and following fires. Experimental investigations are performed to understand the evolution of the material due to elevated temperature.

The senior research associates in the lab used the VIC-3D IR system to find the effects of a simultaneous one-sided heating and compressive loading test on an e-glass/vinyl ester/balsa wood sandwich composite sample. As one researcher stated, “The VIC-3D IR system identied several transient events during the compression tests which would not have otherwise been fully understood using either DIC or IRT independently. Through this testing, several features of sandwich composite thermomechanical behavior  were elucidated which would not have been possible with traditional point measurements (e.g. strain gages, defectometers, or thermocouples).”

Image above: Analysis of simultaneous one-sided heating and compressive loading on an e-glass/vinyl ester/ balsa wood sandwich composite sample, Identifying several transient events, which  would  not  have been  fully  understood  (stated by the enginners of Virgina Tech´s ExtReMe Laboratory) using  either  DIC  or  IRT independently or only applying traditional  point  measurements  (e.g.  strain gages, deectometers, or thermocouples).  Source:  Virgina Tech´s ExtReMe Laboratory