Pre-damage

In the instrumented drop weight tester HIT 230F, the specimen is pre-damage under set conditions. 

The specimens are tensioned on a section of: 
76.2 x 127 mm (ASTM, Boeing, SACMA, DIN), 75 x 125 mm (EN, Airbus) or 140 mm diameter (CRAG). Only the Airbus AITM requires clamping within the section.  To simplify operation, the specimens are tensioned outside the drop weight tester and then inserted into the testing position.

The pre-damaging procedure can be monitored and assessed using the instrumentation of the drop weight tester. The first damage peak on the power-time curve also gives a correlation to the Mode II fracture toughness of the laminate.