Volume 24, Issue 6 (November 1996)
Effects of Fatigue on Fragility Testing and the Damage Boundary Curve
The original concept behind the damage boundary curve (DBC) and the related shock fragility test, ASTM D 3332, are discussed and used to suggest shortcuts in the test procedure aimed at reducing the number of products that must be damaged. A nondestructive means of evaluating the appropriateness of the DBC in describing product fragility using the results of the test is also described. A new test procedure based on a more realistic model of the product that allows for fatigue failure is then introduced and verified experimentally. The result of the test is a series of DBCs for multiple impacts that would allow the expected number of drops in distribution to be taken into account when designing a cushion for the product. Shortcuts in the new test procedure and a nondestructive means of checking the fit between the product and the new model are also proposed.