Challenge

Section Modulus calculation and optimization

GG. Saffwan Syed Asan6 Jul 2021

Section Modulus:

Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members. Other geometric properties used in the design include an area for tension and shear, the radius of gyration for compression, and moment of inertia and polar moment of inertia for stiffness. Any relationship between these properties is highly dependent on the shape in question.

It is termed as the ratio of the second moment of inertia and distance from N.A (Neutral axis) to the extreme fiber. Also, it is the measure of the strength of a given member. The stress in the outermost section of the beam is computed with the help of section modulus. It is indicated by S.

Section modulus is calculated by the below given formula

S = I/y

S = Section Modulus

I = Moment of Inertia

y = distance between the neutral axis and the extreme end of the object

Importance:

• It is significant for beam and flexural member design.

• More the section modulus, the more the member is resistant to the bending of the beam.

• It is easier to calculate stresses in the beam and an exact measure of the strength of steel.

• If two beams are made of the same material and comparing the “section modulus” of two beams, the beam with bigger section modulus will be tougher and more capable to withstand larger loads.