Extension and evaluation of fatigue model for product shock fragility used in package design

Earlier work that incorporated fatigue into the description of the shock fragility of products is expanded to include more sophisticated models of failure. The robust nature of the original model, which treats fragile interior components as single-degree-of-freedom spring/mass systems deforming in an elastic/perfectly plastic manner under dynamic loading, is demonstrated in three ways. The first compares the model predictions with experimental results, which include the generic findings referenced in an ASTM standard. The second and third are based on comparisons with an exact analysis of elastic/linear plastic springs and an approximate analysis of the most general model possible.