Forging new generations of engineers Free Body Diagrams
Forging new generations of engineers
Free Body Diagrams A lesson on creating force diagrams
In This Lesson: What are free body diagrams, and how are they used? What are the types of forces? How do we create free body diagrams? How do free body diagrams apply to pulley systems? How do free body diagrams apply to trusses?
What is a Free Body Diagram?
Newton’s Third Law For every action, there is an equal and opposite reaction. THE TOP ROCK PUSHES DOWN ON THE BOTTOM ROCK PUSHES BACK UPWARD ON THE TOP ROCK
What is a Force? A push or a pull acting on an object as the result of an interaction with another object.
Types of Forces Applied force: one object acts on another Wind pushing on the boat Fapp
Types of Forces Tension force: transmitted through string, cable, wire, rope, or chain the n o lling u p e Rop boat θ F tens
Types of Forces Gravity force: weight; the mass of the Earth pulling on the mass of the boat W Gravity pulling the mass of the boat down
Types of Forces Normal force: support force Water pushing back up on the boat FN
Types of Forces Friction force: opposes the motion of the object Water pulling on boat Ff
What is a Free Body? Substitute a simple shape for the object being analyzed. Fapp F tens Ff FN W
Creating the Free Body Diagram
Creating the Free Body Diagram Ftens θ θ Ff FN W
Creating the Free Body Diagram F app Ff W FN W θ θ Ff FN
Creating the Free Body Diagram Ftens Fapp θ θ WSIGN WELCOME Fapp WSIGN
Your Turn to Create a Free Body Diagram SICS PHY E TUR ITEC H ARC
Your Turn to Create a Free Body Diagram FN SICS PHY HITE RE CTU ARC FN Fapp θ Fapp W W FN θ FN
A Different Method FN SICS PHY RE CTU HITE ARC FN Fapp FN θ Fapp W W FN θ
Pulley Systems Ftens FBD of M 1: M 2 FBD of the movable pulley: WM 1 Ftens WM 2 M 1 Tension Forces (Ftens ) are equal throughout the system.
Trusses B A C L D
Trusses B FAX A C FAY L D FDY
Trusses B FAB FBC FAX A FAC FAY C L FBD FCD D FDY
Trusses B FAB FFBDAB FBC FAX A FAC FAY C L FAC FAY CD NODE A D FDY
Trusses B FAB FBD FBC FAX A FAC C FAB FAY FBC L NODE B FCD D FBD FDY
Trusses NODE C B FBC FCD FAC FAB FBC FAC C L FBD L FCD D FDY
Trusses FBD B FBC FBD FCD C FCD D FDY NODE D L FDY
B Trusses FAB FAX A FAC FAY FBC FBD FBC FCD FAC C FCD FDY D L
References Department of Physics, University of Guelph (n. d. ). Free body diagrams. Retrieved January 29, 2008, from http: //eta. physics. uoguelph. ca/tutorials/fbd/Q. fbd. html Garrett, J. (1999). Truss analysis methods. Retrieved March 2, 2008, from http: //www. ce. cmu. edu/~garrett/courses/12 -100/LECTURES/trussanalysis-ho. pdf Vawter, R. (2007). Free-body force diagrams. Retrieved March 6, 2008, from http: //www. ac. wwu. edu/~vawter/Physics. Net/Topics/Dynamics/Forces/Free Body. Diagram. html
Credits: Writer: Wendy De. Mane Content Editor: Production Work:
- Slides: 30