I am trying to predict failure of a glass panel subjected to varoius loads.
My FE model consists of solid elements. My question is what do I use for a stress criteria which will predict failure. The model will be used for multiple load cases.
glass fails in tension so you should look for the maximum stress intensity
actual failure levels quite strongly dependent upon surface finish/or roughness, polished surfaces are best and failures generally initiates at the edges
typical values would be 2000 psi for tension but upwards of 40,000 psi in compression
schott has data relating to rate-of-stress application vs failure
Weibull analysis generally used for this kind of failure
be very cautious about the restraints/boundary conditions for any material that is subject to brittle failure
look for works by P Yoder and V Genberg
Thankyou for the insight. I will look into the reference. Initially I was using a max tensile principal stress and I will dig a little deeper. Thanks again.
Glass is a brittle material which makes it very flaw sensitive. Glass fibers have a tensile strength of 500,000 psi, far high than monolithic glass. Tempering glass makes it far stronger by simlpy changing the distribution of internal stresses. The right FEA model should be able to take this all into account.