Volume 18, Issue 4 (July 1990)
Instrumented Impactor for Testing Wood-Base Floor Panels
The current ASTM method for evaluating impact resistance (ASTM E 661), which uses a leather bag filled with 14 kg (30 lb) of lead shot, is adequate for comparative rating of panels. Our objective was to obtain a more precise measure of failure initiation. An instrumented steel impactor was developed to evaluate the impact resistance of single-layer wood-base floor panels. Panel materials evaluated were plywood, waferboard (two manufacturers), and oriented strandboard. All were nominally 19 mm (¾ in.) thick with tongue-and-groove edges and were approved for single-layer flooring. Impact resistance tests were conducted on the panels using a 14-kg (30-lb) lead-shot bag, a 14-kg (30-lb) steel impactor, and a 27-kg (60-lb) steel impactor. Floor panel damage was measured by the amount of energy absorbed by the panel, time to maximum deflection, and residual panel deflection (permanent set). The 14-kg (30-lb) impactor proved to be more precise for identifying damage initiation because the 27-kg (60-lb) impactor caused complete failure of some waferboard and oriented strandboard after only two or three drops. For all panel types, the 14-kg steel impactor caused 30 to 40% greater deflection than the 14-kg lead-shot bag for any given drop height.