Beam is a horizontal structure member used to carry vertical load, shear load and sometime horizontal load. It is the major component of building structures. It mainly use in construction of bridges, trusses, and other structures which carry vertical load. Beams may be define as:
Any structure member which cross section is much smaller compare to its length and undergoes lateral load, known as beam.
In other words beam is a horizontal bar witch undergoes lateral load or couple which tends to bend it or a horizontal bar undergoes bending stress known as beam.
According to its requirement, different beams use in different conditions like fix beam, cantilever beam etc.
Types of beams:
Beams are classified as follows:-
According to end support:
1. Simply Supported Beam:
As the name implies, simply supported beam is supported at both end. One end of the beam is supported by hinge support and other one by roller support. This support allow to horizontal movement of beam. It beam type undergoes both shear stress and bending moment.
2. Continuous Beams:
When we talk about types of beams we cannot forgot continuous beam. This beam is similar to simply supported beam except more than two support are used on it. One end of it is supported by hinged support and other one is roller support. One or more supports are use between these beams. It is used in long concrete bridges where length of bridge is too large.
3. Overhanging Beams:
Overhanging beam is combination of simply supported beam and cantilever beam. One or both of end overhang of this beam. This beam is supported by roller support between two ends. This type of beam has heritage properties of cantilever and simply supported beam.
4. Cantilever Beams:
Cantilever beams a structure member of which one end is fixed and other is free. This is one of the famous type of beam use in trusses, bridges and other structure member. This beam carry load over the span which undergoes both shear stress and bending moment.
5. Fixed beams:
This beam is fixed from both ends. It does not allow vertical movement and rotation of the beam. It is only under shear stress and no moment produces in this beams. It is used in trusses, and other structure.
According to cross section:
A beam may have different cross section. The most common cross section of beam are as follow.
1. I beam:
This beam types have I cross section as shown in figure. It has high resistance of bending.
2. T beam:
It has T cross section as shown in figure.
According to equilibrium condition:
1. Statically determinate beam:
A beam is called determinate beam if it can be analyze by the basic equilibrium condition. The support reaction can be found by using basic equilibrium condition. These conditions are
Summation of all horizontal forces is zero.
Summation of all vertical forces is zero.
Summation of all moments is zero.
Example: Simply supported beam, Cantilever beam etc.
2. Statically indeterminate beam:
If the beam cannot be analysis by using basic equilibrium condition, known as statically indeterminate beam. The end reaction find out by using basic equilibrium condition with combination of other conditions like strain energy method, virtual work method etc.
Example: Continuous beam, fixed beam
According to Geometry:
1. Straight beam
2. Curved beam
3. Tapper beam
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