StrainMaster Advanced Digital Image Correlation Systems for Optical Full Field Measurement of Material Strain, Displacement and Shape LaVision FOCUS ON IMAGING

Optical Technology for Full Field Strain Measurement StrainMaster from LaVision combines the most advanced Digital Image Correlation (DIC) algorithms with the highest quality hardware to provide a complete device for materials analysis. StrainMaster is applicable across all industries investigating material behaviour and gives fast, highly accurate results via an easy to use PC based interface. A range of StrainMaster systems are available from portable field work machines to highly specialized lab versions. Any system can be tailored to suit your particular requirements, and are appropriate...

Digital Image Correlation Digital Image Correlation (DIC) is a method to compute local displacements in a sequence of images showing some kind of specimen deformation. The images are discretized into small subsets of NxN pixels, and the algorithm tracks the pattern within each subset. Where the pattern matching is maximized (or the differences minimized), this represents the local displacement. Repeating this across the entire image for all subsets yields a full field map of data, which is similar to having thousands of virtual extensometers or strain gauges on the sample surface. Moreover, by...

The StrainMaster software features a simple workflow enabling users to get reliable results quickly. 4set-up aids including focus and dynamic range indication 4one view 3D calibration in less than 60 seconds, and advanced polynomial calibration modes for configurations such as stereo microscopes 4accurately synchronized image and analogue input acquisition via the recording dialogue, or import images from a standalone camera 4flexible masking of the image to define the zone(s) of interest 4choice of time-series mode, subset parameters, and calculation type 4ability to inspect the quality of the...

StrainMaster Full Control The DaVis platform offers complete hardware control, with no need to rely on home-made triggering or separate multiple control programmes. It is possible to build acquisition loops and specialized timing schemes. 4standard and high-speed cameras 4data loggers for analogue data acquisition 4translation stages 4pulsed light sources Phase locked recording of cyclic events such as fatigue testing is possible with the StrainMaster Controller, and post-triggering of high-speed events such as Split-Hopkinson pressure bar tests is straightforward. Operating in live mode, or...

for Industrial and Research Testing The range of applications where StrainMaster has been applied is vast, spanning all research sectors and specimen scales, from microscale to metres. A few examples are shown here but further detailed examples can be found in our separate application notes. Composite materials are extensively used in aerospace and other high performance applications, particularly where speed and manoeuvrability are primary considerations. Full-field data-rich imaging techniques are used to provide a better understanding of the behaviour of composite materials subjected to high...

DIC and DVC have been successfully applied to skin tissue, bone, teeth (see left) and implants. Biomechanical applications often require very small fields of view necessitating specialized optics. One such example is the study of Nitonol shape memory alloy which is used in endovascular stent graft systems produced by Vascutek Ltd. By using a StrainMaster system equipped with a stereo microscope it was possible to gain an understanding of the functional behaviour of small scale (< 0.5 mm diameter) Nitinol wire. Analysis of implant-supported dental restorations, courtesy of Dr. R.Tiossi, Dental...

Advanced Solutions StrainMaster Upgrades and Specialist Applications Understanding of strain rate effects on material behaviour is important in the case of structures subject to dynamic, shock, impact or blast loading. Full-field data-rich imaging techniques are used to provide a better understanding of composite, metal, and plastic material characteristics at high strain rates. High-speed StrainMaster systems feature fully integrated high-speed cameras with kHz frame rates. Small Scale Micro-DIC Understanding the mechanical and material behaviour of microscale components is extremely challenging...

Multi-Camera Multi-Parameter StrainMaster Multi-Camera Systems The dual level, two-sided calibration plates allow more than two cameras to be calibrated within a single co-ordinate system. Together with the advanced PTU X controller, these cameras are accurately synchronized to obtain surface measurements from both sides of a panel, for example. Thickness map of an impact damaged composite panel, courtesy of X. Sun and Dr. S. Hallett, University of Bristol Fluid-Structure Interaction (FSI) Combined Fluid Flow and Surface Deformation Combined Infra-Red Temperature and Strain Measurements Interaction...

Digital Volume Correlation StrainMaster Going beneath the Surface StrainMaster Digital Volume Correlation (DVC) is a powerful extension of DIC and provides full volume 3D strain and displacement measurements. The material‘s natural or artificially introduced internal pattern is tracked between subsequent volumes, as illustated below for the case of a „sand box“ tectonic plate simulation. The obtained 3D full-field displacement and strain maps allow the user to truly understand the subsurface material behaviour and validate complex simulations, and in the case below visualize the shear bands developing...

StrainMaster Portable StrainMaster Compact and Portable DIC System Suitable for a huge range of applications where flexibility and portability is essential, we have developed LaVision‘s StrainMaster Portable system to be appropriate for a wide range of applications. It allows the user to quickly and easily obtain full field data over the entire material surface. Ease of use is enhanced by the inclusion of polarization filters on the LEDs and lenses (patent EP1739403B1) to avoid undesirable specular reflections which can confuse the correlation algorithms causing reductions in data quality. Polarized...