What is beam? How the beams are commonly loaded?

Beam: A beam is a piece of structure which may be designed to support any type of lead, but in general, It is required to carry the load at the right angle to its longitudinal axis.

Beams are commonly loaded with the following types of loads:

Types of loads

A beam may be loaded in a variety of ways. For the analysis purpose, it may be spitted into three categories:

1.     1. Concentrated or point load.

2.      2. Distributed load:

(i)               Uniformly distributed load

(ii)              Uniformly varying load

   3. Couple

 

1. Concentrated load

A Concentrated or pointed load is one which acts over so small a length that it is assumed to act at a point. Practically, a load can not be placed as knife edge contact but for calculation purpose we consider that load is being transmitted at a point. Fig. concentrated load represents point loading at points A and B.

                                        

Fig. concentrated load 

 

2. Distributed load

A distributed load ats over a finite length of the beam. A Distributed load may be uniform over the length, or it may be very uniformly or non-uniformly. Such loads are measured by their intensity which is expressed by the force per unit distance along the axis of the beam. Fig. distributed load represents distributed loading between points A and B.

 

 

Fig. Distributed load

 

 

(i) Uniformly distributed load :

A uniformly distributed load implies a constant intensity of loading (W). It is generally abbreviated as U.D.L and its unit is KN/m. Fig. U.D.L Represents a U.D.L between points A and B.

 

Fig. Uniformly Distributed Load

 

(ii) Uniformly varying load :  

A uniformly varying load implies that the intensity if loading increases or decreases at a constant rate along the length.

 

W= Wₒ + k. x

 

Where K is the rate of change of the loading intensity, Wₒ being the loading at the reference point.

 

uniformly varying load 

uniformly varying load

uniformly varying load

    Fig. uniformly varying loads.

 

Such loading is also known as a triangularly distributed load. Fig. Uniformly varying load represents such a loading between points A and B. Sometimes, the distributed loading may be parabolic, cubic, or a higher order curve for non-uniformly varying load i.e.,

W= Wₒ + k₁ x + k₂ x² (parabolic)

 

W = wₒ + k₁ X + k² x² + k₃ X³  (cubic) and so on.

 

3. Couple

A beam may Also be Subjeted to a couple ‘’µ” at any point. As Shown in Fig. couple.

Fig. Couple Load

Note: In General, the Load may be a Combination of Various Types of Loadings.

 

I hope this Information will help you in studies. Please like and comment if you find it knowledgable.

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