Technical Challenge

A plastic clip used to retain a patient support failed, resulting in an occupant death. Veryst was asked to determine the cause of failure.

Veryst Solution

Veryst performed material analysis of the clip, examined the fracture surface, and performed a multistage, nonlinear finite element analysis to calculate the stress history within the plastic component from installation up through daily use.

The analysis demonstrated (and illustrated in the animation to the right) that the stresses due to installation exceeded the yield stress of the plastic and compromised the integrity of the clip.