BEAM is a horizontal member which carries load primarily by bending. Meaning its a flexural member.BEAM can resist vertical gravity loads (self-weight, floor loads, live loads) and horizontal loads (lateral forces like wind, earthquake)
BEAM take axial loads- tension taking members are called tie beams and compression are called strut beams.BEAM analysis is done assuming different end- conditions like simply supported, continuous, cantilever, fixed. Analysis using force methods and displacements methods. Recently Finite Element Method has been vital in the analysis using the software.
BEAM design involves assigning shapes and reinforcement (r.c.c). Rectangular or T shaped is most commonly used in R.C.C.I shaped or L shaped ( Angle sections ) or C shaped (channel sections )used in steel
BEAM experiences bending stresses (compressive and tensile in nature) and shear stresses.
BEAM properties like stiffness (elasticity modulus (E) and second moment of area (I)) are very important in calculating deflections. deflections are important in terms of safety and appearance.
Classification of Beams:
Classification of beams is basically based on:-
- Classification of beams based on supports
- Classification of beams based on geometry
- Classification of beams based on the shape of cross section
- Classification of beams based on equilibrium conditions
- Classification of beams based on material
Beams are classified on the basis of their geometry and the manner in which they are supported.
Simply Supported beam :-
Abeam supported on the ends which are free to rotate and have no moment of resistance(MOR).The beams are said to be simply supported if their supports creates only the translational constraints.
Abeam supported on both ends and restrained from rotation.
A simple beam extending beyond its support on one end.
Double overhanging beam :-
A simple beam with both ends extending beyond its support on both ends.
Continuous beam :-
A beam extending over more than 2 supports.
A beam which is supported on the fixed support is termed as a cantilever beam: Now let us understand the meaning of a fixed support. Such a support is obtained by building a beam into a brick wall, casting it into concrete or welding the end of the beam. Such a support provides both the translational and rotational constrained to the beam, therefore the reaction as well as the moments appears, as shown in the figure below
Abeam strengthened by adding a cable or rod to form a Truss.