Ductile Failure (Impact)

Material failure mode that is characterized by a significant yielding and plastic deformation along with cracking. The load-time curve for an instrumented impact shows a zero-slope area around the maximum and extends in time beyond the point of maximum load, with the specimen still absorbing energy.

In drop tower tests, the tup (falling dart) leaves a hole or rupture through the full thickness of the specimen rather than cracking outwardly form the point of failure. The impact area shows elongated and thinned parts.