Statics Problem 5-73: Equilibrium of a Rigid Body with three Journal Bearing Supports

Statics Practice Problem with three journal bearings. Example of equilibrium of a rigid body with journal bearing supports. Journal bearings apply both force and moment reactions but if they are aligned, they only apply force reactions. Whenever there are journal bearing supports, equations are coupled, so we have to solve six equations simultaneously to find our six unknowns.

[johndo]

Thank you for this video! I was wondering whether we could choose the origin as the point to calculate the moment? I've tried it with the origin and it seems like I get the wrong answers :(

[GenDrag]

For future travelers:

Ax, Az, By, Bz, Cx, and Cy can be found by

-using Bz + 2Cx = 0, turn it into 2Bz = -4Cx, and replace 2Bz in i=0
-using 200 + By + Cy = 0 from sigma-Fy = 0, turn it into -By = 200 + Cy, and plug it into k=0 equation for -By

- set equal to each other: -1385.6 - 4Cx - 2Cy = 0 AND your =984 -4Cx -1.5Cy = 0
-Now you have Cy
-Solve for By
-Solve for Bz
-Solve for Cx
-Solve for Ax and Az, just because we took the moment about A doesn't mean we can forget about them :p

and that's it
saved you what was for me 3hrs and 41 minute

good luck traveler

[anthonygutierrez]

Wouldn't it be 2j for the AD position