Final Master’s Project
Joseph Hughes
Finite Element Analysis of Fatigue on an Overtoggle Mechanism
The purpose of this study is to analyze the stress in components that comprise an
overtoggle mechanism throughout its motion. Overtoggle mechanisms are often
used within four bar linkages to maintain the position of the mechanism. In order to
achieve the overtoggle position, a large amount of force is placed into the
mechanism as the components are either compressed or stretched to achieve
overtoggle. This analysis will evaluate the stresses within the mechanism as it
passes into and out of the overtoggle position. The amount of stress can be different
if the mechanism is passing into of out of the overtoggle position. This evaluation
will be completed using Abaqus to analysis the stress distribution within the
mechanism. This analysis will also perform a sensitivity analysis to the amount of
stretch or compression required (i.e a small change in the required compression
from a different compliant material could cause a much higher stress in the system).
This analysis can be compared to a friction circle hand calculation to verify the
analysis.