METHOD AND APPARATUS FOR DROP WEIGHT IMPACT TESTING

摘要

A test fixture (10) of the type that requires repeated manual lifting of weights in a drop-tube (16) for performing an ASTM drop weight test, is provided with a computer (100) automated pneumatically powered lift mechanism. The lift mechanism (32) for the weights responds to a series of computer generated signals that are applied to a set of electropneumatic actuators for driving pistons to lift and drop the weight. Associated with the lift mechanism is a set opto-interrupter devices (101) that generate a position signal representative of the position of the weight to be dropped as it ascends in the drop tube. In use the computer is provided with a desired drop height and essentially continuously compares the position signal with the desired drop height and releases the weight in the drop tube to impact a sample material (22) when the position signal equals the desired drop height.