The new LDV PULL-OFF instrument is the evolution of the POT PULL-OFF tester. Conceived and developed entirely by DRC SRL, the instrument features a kit of accessories which make it even more flexible in use and suited to a wide range of applications. The LDV Pull-Off Tester provides to perform:
- Standard adhesion test – PULL-OFF standard UNI EN 1542:2000
- Shear force test – CNR-DT 200/2004 Instructions for the design, execution and control of static consolidation work employing reinforced composites and fibre.
The procedure, in both cases, consists in gluing a metal plate to the material being tested and attaching it to the instrument, which exerts either a traction or shear force to it, depending on the test.
The new LDV PULL-OFF instrument is composed of :
- contrast support;
- loading cell and removable display system;
- adjustable ball traction handles;
- support extensions;
- lower contrast support for shear test;
- pull-off plate D50;
- shear test plate L 150 x 50;
- calibration report;
- user manual;
- rigid carry case.
The Pull-Off system is the only commercially available instrument which, using a load cell to measure the adhesion or shear force, can measure small values without compromising its excellent accuracy. All without the measurement errors typical of hydraulic methods.
The load cell reading system connects to a portable display which shows the force reading in real time, and logs/displays the peak value. It can also be connected to the multifunctional DaTa 500 system for displaying the force both numerically and graphically.
Support extensions and applications:
Thanks to its versatile attachment system, the LDV Pull-off tester can be used for testing the adhesion of mechanical components (anchors) and components which are larger than conventional plates, using support extenders.The extended point of support makes it possible to test elements which are larger than normal adhesion plates.
Shear tests on composite materials:
Shear tests apply a traction force to a strip of composite material along its length, thus distributing tangential stresses across the interface between the reinforcement and the substrate as specified by ASTM D 905.
As indicated in the CNR document, the test is particularly valuable in determining the quality of adhesion. The application can be considered acceptable if at least 80% of the tests (both, if only two are run) register a peak force at failure of no less than 24 kN.
The Pull-Off tester for shear testing composite structures includes a position-adjustable lower contrast plate and the anchor plates for the material being tested.
The instrument consists of a lower support which is bolted to the substrate to which the material being tested by the LDV Pull-Off tester is affixed.