I think that fail-safe might be a more productive route for turbines -- Think how car windscreens have evolved from big lethal broken shards through regularly shaped small bits to the current 'broken but still hanging together' approach
If you're suggesting that the engine casing should be able to retain any parts from a broken turbine breaking out, that's simply not feasible.
the speed/energy in these parts (especially at take-off power) is simply staggering, you would need something like several inches of Chobham armour backed with heavy armour plate.