Sign convention - solving problems of beam, Mechanical Engineering

Sign convention which is used for solving problems of beam:

Although different sign conventions can be used, most of the engineers use following sign conventions for shear forces and bending moment.

(i)  Shear force which tends to move left portion upward relative to right portion shall be called as positive shear force.

 

1226_sign conversion.png

(ii) The bending moment which is trying to sag (Concave upward) beam shall be taken as positive bending moment. If the left portion is considered positive bending moment comes out as clockwise moment.

 

2307_sign conversion1.png

To decide sign of moment because of a force about section, assume that the beam is held tightly at that section and observe deflected shape. Then looking at shape sign can be assigned.

Shear force and bending moment vary along the length of the beam and this variation is represented graphically. The plots are called as shear force and bending moment diagrams. In this type of diagrams, the abscissa indicates position of section along the beam, and ordinate represents the value of Shear Force and BM respectively. These plots assist to determine maximum value of each of these quantities.

 

1727_sign conversion2.png

 

Posted Date: 10/20/2012 1:22:25 AM | Location : United States







Related Discussions:- Sign convention - solving problems of beam, Assignment Help, Ask Question on Sign convention - solving problems of beam, Get Answer, Expert's Help, Sign convention - solving problems of beam Discussions

Write discussion on Sign convention - solving problems of beam
Your posts are moderated
Related Questions
in the spiral or helical gears- have meshing gear different helix angle?


Work related area of CAD Work related to the following areas has been addressed in this interface.  Investigation of CAD data structures and the presentation of 2-D and


Is there a metal that does not contain iron? Ans) Most commercially available aluminum having some other materials, but only accidental traces of iron, if any. For example, Copp

Q. What is meant by dynamically induced emf and statically induced emf? On what factors do these depend? Derive eq. for these two emfs.   Sol. Dynamically induced emf:

Write short notes on following terms:- (i) Total quality management (ii) Method study (iii) Selective Inventory Control (iv) Break Even analysis (v) Merits Rating an

Nitrides, Silicides and Sulfides Nitrides contain very high melting point but initiate to oxidize at low temperature. They have poor resistance also to chemicals. Boron nitrid

Level of Safety Organization This level comprises representatives of safety departments working at shop floor level or along with workers. The personnel will in fact implement

The tank can be modelled from first principles with the provision of certain assumptions. For the sake of simplicity, it is possible to consider the top section of the tank with p