Bending Review for Mechanical Design in Under 10 Minutes! (Updated Version Below!)

[@chrisb7161]

Hi thanks for your videos they are very nice. In regard to the 2nd moment of area, is the y value in the integral equation squared to account for the moment lever arm contribution above and below the neutral axis? I have always wondered where the y^2 and x^2 terms come from for the Ixx and Iyy equations respectively.

[@LessBoringLectures]

Thanks! For bending, specifically, yes, the y^2 or the x^2 come from the lever arm (one x or one y) times the force, which in turn, is also a function of x or y. So it results in x^2 and y^2. Completely separate from bending or any kind of stress, the first *moment* of area is defined as the area times the length (integral of y dA), and the second moment of area is defined as the area times the length squared; and so forth for third, fourth, etc.

[@chrisb7161]

@@LessBoringLectures Thanks for the clarification.

[@williamhuang5329]

Hanzhen harmonic drive gear , robot arm gear , over 30 years experience ,

[@shankarbablu8279]

Can you please suggest me alternative option for flexible bearing in harmonic drive??