Mechanical grips for miniaturized tensile specimens

Mechanical grips for miniaturized tensile specimens

The mechanical grips were developed at COMTES FHT a.s. for the purpose of testing miniaturized tensile test specimens. Miniaturized test specimens are ideal for characterizing localized properties of parts or for assessing the material qualities of 3D-printed components. The grips allow perfect clamping of the sample without any tensioning, bending, twisting or other undesirable effect during clamping process. The grips have sufficient pressure for a wide variety of materials, preventing slipping or bending during testing even for high strength materials. The design of the grips was developed for measuring deformation using by optical systems (including DIC analysis). The miniature tested body of the specimen is fully visible in the measured area.

The grips are suitable for testing samples according to ASTM E8/E8M-24 (Annex A1 - Miniature specimen 2 and 5) and EN ISO/ASTM 52909-22 (A.6 - Figure A.6a).

Parameters

• Fixing of grips to the standard clamping pin Ø 20 mm with a mandrel Ø 8 mm (e.g. Zwick system)
• Loading: tension
• Maximum load for the body according to ASTM E8/E8M:24 (Miniature specimen 2 and 5) - 1 kN (2000 MPa)
• Maximum load 3 kN.
• Teplota zkoušení: 23±10°C
• Maximum clamping dimension: approx. 10x15x1.5 mm.
• Strain measurement is possible with the optical systems (e.g. video extensometers).
• Overall dimensions of one grip: height 125 mm, width 250 mm (including tightening handles)

Other

• It is advisable to consult the required geometry of the bodies and load when ordering.
• The grips are supplied as standard with flat replacement inserts. The inserts ale also available as spare parts.
• Fixation of grips can by adjusted according to requirements.
• The Alignment Fixtures is recommended for precise centring of machine.

The utility model, internally designated as VFU2200002, was developed as part of the national TRIO project in the 4th public competition. This project, titled "FV40166 Assessment of Degraded Steels for the Construction of Turbine and Superheater Components in Power Plant Boilers," was funded by the Ministry of Industry and Trade (MPO).