The Eyring Model
The Eyring Model for Accelerated Testing
Sometimes the reaction rate of a process relies on two stresses. For chemical reactions temperature seems to influence the rate of the reaction. Yet, other stresses such as humidity or voltage may also play a significant role.
H. Eyring suggested a model that assumes the contribution of each stress on the reaction rate is independent thus one could multiple the respective stress contributions to the rate of reaction.
The Erying model provides a means to account for the contributions of temperature and another stress when modeling the time to failure of select failure mechanisms.
The Erying Model General Form
The model includes the Arrhenisus model for the temperature contribution, and an inverse power law term for another stress.
The general form of the model is:
Where
t is time (nominal product life)
A and B are constants related to the specific process being modeled
S is the applied stress
Ea/kT is the activation energy divided by Boltzmann’s constant and temperature in Kelvin
