Agree with above posts - built in stresses (owing to mis-alignment etc) ; thermal stresses and projectile damage are probably the leading causes in automobile windows cracking. (not in order)
I remember the winter of 2000 in delhi, after a particularly cold night, our Maruti 800 front windscreen had cracked up completely (at about 0800 when temperatures were starting to climb again) - and the very same night, the Air force Motor transport section had 5 different cat.s of vehicles (from vans to 6 Tonners) with similar damage.
The freakiest I've seen is the forward porthole (window) of a Gas Carrier (a ship carrying liquified glass) exploding during operations - the failure was attributed to a combination of fatigue, thermal stresses and structural stresses - fyg, the window was 14mm thick safety glass in a reinforced aluminum alloy frame. And I've never seen any ships glass crack like that before! |