Statics Lecture 20: Two-force and Three-force Members

Frames and Machines Example

Problem Solving Method:

1. Draw a FBD of the entire frame
2. Dismember the frame, and draw a FBD of each member.
3. First consider the 2-force members.
4. Consider multiforce members
     a.) multipforce connected to 2-force
     b.) multiforce connected to multiforce

5. Determine all internal forces
   a.) 3 equilibrium equ's / FBD
- Choose carefully where to take your M around!
Try to get only one unknown in your M equ.
- T or C??? Guess it is T, then pay attention to your signs!

Examples: 6.75, 6.87 a), 6.88 a)