But on the midterm or exam, you never know what type of 3D supports you will have to work with while you are most likely required to have them memorized. It is hard to memorize all the support reactions. There are a number of different supports for 3D rigid body equilibrium, as you saw. Interestingly enough, our legs are joined by a ball-and-socket joint to our hipbones. Examples of 3D rigid body equilibrium analysis in engineering include: reaction force and moment analysis of airplane wing during takeoff, calculating reactions on construction equipments during operationīall-and-socket joints are one of the most practical supports in mechanical systems engineering. However there are many engineering problems that require 3D rigid body equilibrium analysis. Since 3D rigid body equilibrium analysis is time consuming due to forces and moments in 3 dimensions, 2D rigid body equilibrium analysis is always preferred.

However, the rigid body equilibrium concepts in 2D and 3D are no different, where the net force and moment in all directions must be equal to zero to maintain static equilibrium. The types of reaction supports from 2D rigid body equilibrium are not applicable to 3D rigid body equilibrium.

3D rigid body equilibrium analysis involves calculating forces in the x,y, and z direction, as well as calculating moments about the x,y, and z axis.

Static equilibrium 3d