Section Modulus calculation and optimization

Section modulus: It is defined as the ratio of moment of inertia of a section about the neutral axis to the distance of the outmost layer from the neutral axis.

it is the direct measure of the strength of the shaft section or beam section. higher the section modulus of a structure, the more resistive it becomes to bending. 

mathemetically it is expressed as 

S=I/Y

where,

S=section modulus

I=moment of inertia

Y= distance from neutral axis to extreme end

Moment of inertia: The moment of inertia is the capacity of a cross section to resist bending. when it is subjected to an external load.

it is directly propotional to the strength of the material, which can be calculated through section modulus.

• Length caluculated for the section as below

• For the first section calculated moment of inertia as below

• for the second section moment of inertia calculated by increasing section area
• section area increased by 0.75mm offset distance for inner panel to outside

SECTION MODULUS CALCULATION:

Hence it is proved That S value increased with increasing cross section area. 

• section 2 has more section modulus than section 1 
• Bending strength increases with increasing in section modulus so section 2 is stronger for bending loads.