Definition of Beam:

Beam is a horizontal member of a structure which transfer the loads to the vertical members of the structures.

Assumptions for Designing of Beam:

1. The concrete is assumed to be homogeneous.

2. All of the tensile stresses are taken up by the steel reinforcement and the compression stresses are taken up by the concrete except where are permitted.

3 . Concrete area on the tension side of section are assumed to be ineffective.

4. Section which are plane before bending remain plane after bending.

5. The stress-strain relationship of steel and concrete is straight line under working load.

6. The modular ratio(m=280/3fc) is taken where fc=permissible stress in concrete in compression due to beding in Newton per square mm.

7. No slip takes place between steel and concrete

8. Steel has no initial stresses.

assumptions for beam design