I worked with an ex-Boeing Engineer and we discussed turbulence on a flight to DFW once (we had really, really bad turbulence on the flight). He told me that for the normal being tossed in the sky stuff, the plane was built to such high standards that before turbulence would take the plane out of they sky through bouncing etc., the wings would be ripped off.

It was something like 5 or 6 G's of force on the wing was necessary for that to happen, a level virtually unheard of in commercial aviation. After that was never bothered by it.

(fyi I can't remember the exact G force, but much more than humans can stand is the way he phrased it)