Lecture 4 part III

Lecture 4 part III - PART III Contents: COUPLES (cont)...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
41 PART III Contents: COUPLES (cont’) SIMPLIFICATION OF A FORCE SYSTEM: RESULTANTS
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
42 Resolution of a force into a force and a couple In some mechanics problems, especially when a concurrent force system is needed , it is convenient to resolve a force F shown in Fig. 4-13 a and b into a parallel force F and a couple O M at point O of interest, as shown in Fig. 4-13 c and d . This is done by adding two equal, opposite, and collinear forces at the point O . Fig. 4-13 Resolving a force F into a parallel force F and a couple C Conversely, a force and a couple lying in the same plane can be combined into a single force in the plane, as we observe the charts conversely from Fig. 4-13 d to a . The sole external effect of combining a couple with a force is to move the action line of the force into a parallel position . The magnitude and sense of the force is the same. Example 4.19
Background image of page 2
43 Force magnitude Position vector / 20sin 25 30cos25 35.64 in. AO d °° =+= Couple caused at point O Example 4.20
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
44 Force F in Cartesian form Couple in Cartesian form Couple magnitude Direction angles
Background image of page 4
45 SIMPLIFICATION OF A FORCE SYSTEM: RESULTANTS Coplanar force systems For a coplanar force system consisting of F 1 , F 2 , …, F n , the resultant force R as shown in Fig. 4- 14 a can be expressed as Fig. 4-14 Resultant R for a coplanar system forces xyxy R RR =+=+ = RR R i j e (49) where x xy y R FR F == ∑∑ () 2 2 R FF + R cos cos x y θ =+ ei j cos , cos y x F F R R θθ (50)
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/20/2009 for the course CVEN 221 taught by Professor - during the Summer '08 term at Texas A&M.

Page1 / 16

Lecture 4 part III - PART III Contents: COUPLES (cont)...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online