On a "heavy" WN Flight last year, we encountered very severe turbulence on approach into JAN. I mean bad...probably the worst I've ever encountered on any flight. Women pax were screaming and the people sitting next to me had a death grip thing going on with the arm rests. I kind of chuckled, and just relaxed back into the seat and rode it out.

@ the OP-the chances of Boeing metal breaking apart under severe turbulence is VERY slim to none. You'll get numb the "bumps" eventually after you've experienced them so many times.