Digital Image Correlation System Aramis research
The laboratory of optical systems for measuring displacement and deformation of materials, elements and building structures is equipped with the Aramis system using the digital image correlation (DIC) technique.
During the test, the apparatus allows for three-dimensional measurement of the surface deformation of the tested elements or the measurement of the displacement of any points on the tested surface in flat and spatial elements. The results are presented during the test in the form of standard charts as well as in a graphic form that illustrates the behavior of the tested element.
The research carried out at the Laboratory of Civil Engineering of the Faculty of Civil Engineering at the Silesian University of Technology with the use of the Aramis system includes:
Compressive strength test on cubic elements with dimensions of 100 × 100 × 100 mm according to the recommendations of PN-EN 679: 2008 Determination of compressive strength of autoclaved aerated concrete.
The system also allows the registration of deformation of cylindrical samples and the analysis of cyclic loads.
The use of digital image correlation enables the registration of deformations in a manner analogous to traditional extensometers, as shown on the example of tensile strength tests of wood samples and steel samples.
The ability to register the displacement of any point on the surface of the element allows for the elimination of traditional inductive displacement sensors that can be damaged, e.g. in the study of masonry structures.
One of such tests is the compressive strength of masonry. The main aim of the research was to determine the fvo initial shear strength and G modulus of deformation according to ASTM E519-81 Standard Test Method for Diagonal Tension (Shear) of Masonry Assemblages.
The test elements were embedded in special steel sockets so that one of the diagonals was set vertically and the arms of the steel fitting covered about 1/10 of the length (height) of the tested element (ASTM E519-81 Standard Test Method for Diagonal Tension (Shear) of Masonry Assemblages) . The sockets are equipped with cylindrical joints that eliminate the effects of accidental eccentricities occurring during loading. The test models equipped with steel fittings were placed on a trolley under a steel frame and loaded with a constant increase in the displacement of the hydraulic cylinder piston until the element was destroyed.
The presented system allows for testing changes in the state of displacements and deformations in an area with the maximum dimensions of 2.4 m × 2.1 m, which allows it to be used in testing the compressive strength of brick wall models made on a natural scale.
The optical system allows you to record the tests until the complete destruction of the element.
