In the second post of this VII series, we’ll explore how impact affects glass container strength and the effects of multiple impacts of varying intensity.
As is the case with other fragile materials, glass strength is heavily dependent on its damage condition.
Pristine glass is as resistant as steel. However, if that pristine glass is scratched against a metal or glass, its resistance will drop dramatically. The important conclusion here is to understand that glass doesn’t have a specific strength value.
In order to determine the probability of glass to survive under a certain load, Weibull distribution is the most widely employed in the different research papers covering glass strength topics.
Taking into account that stress is proportional to impact, Vidrala’s experience, after impacting several thousands of containers and after doing some mathematical tricks like using the Taylor series, allowed them to calculate the probability of failure for a given impact.
Multiple Impacts of Variable Intensity
When a container goes through the filling line it receives multiple impacts of variable intensity. In order to calculate the probability of failure under such a complex load case, we will make the following assumptions: