Failure Analysis of Restaurant Glass Coffee Mug

Failure analysis laboratory performed a root cause failure analysis on a restaurant glass coffee mug that failed unexpectedly when it was lifted off the table and injured a server. The bottom of the mug separated from the rest of the mug . The origin of the failure was on the interior of the mug at the bottom. It appears as if a hard object had hit the mug interior at the bottom. This can happen when silverware is put in the mug when a table is being cleared. This mug will see severe thermal cycling during its lifetime, and over time, this could have caused the impact damage to grow into a large crack that would cause this type of failure.