Supports for Rigid Bodies (Space Structures):

The primary step in solving equilibrium problems is to draw free-body diagram. Isolate the body through its surrounding. Replace the constraints by reactions. Illustrate all of the forces working on the member and apply the equations of static equilibrium.

In the common case of a system of equilibrium, there are six equations of static equilibrium. These ensure that the resultant force & resultant moment both are zero.

1. ∑ F_x  = 0

2. ∑ F_y  = 0

3. ∑ F_z  = 0

4. ∑ M _x  = 0

5. ∑ M _y  = 0

6. ∑ M _z  = 0

here x, y and z are the three mutually perpendicular axes.