Section Modulus

Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members.Section Modulus can also be defined as the ratio of total moment resisted by the section to the stress in the extreme fibre which is equal to yield stress.Also, Section modulus is the direct Measure of Strength of a beam. Higher the Section Modulus higher will be the Resistance to Bending.

Section modulus is indicated as follows:

S = I/Y

Here, I is “moment of inertia” and y is distance from “neutral axis” to top or bottom of fiber.
Unit of a “section modulus” is mm³

Section modulus can also be defined by using the simple bending theory as,

We know that, M/I=σ/Y

i.e, section modulus is also expressed as the ratio of bending moment to the bending stress.Therefore,Larger the Section Modulus value larger the resistance of bending

Considering Stainless Steel AISI 302.Therefore,y = 520 MPa

Existing Hood Section Modulus:-

Modified Hood Section Modulus:-

As seen In above firgure,

In this Parent Hood design, minimum Moment of Inertia(MOI) is 1.278172005e+004[mm^4].

As we absorb in above equation of Section modulus,

Section modulus is directly proportional to Moment of Inertia(MOI)

In this New Hood design,

The Distance between inner hood and outer hood is increased by 0.7 mm. Minimum Moment of Inertia(MOI) is 1.332338861e+004[mm^4].

So as the MOI increases the Section Modulus Increases.

MOI of Modified Hood is Greater than MOI of Parent Hood.Therefore, Section Modulus of Modified section is Greater than Section Modulus of Parent section.

A modification in distance leads to increase in Sectional area, results to variation of section modulus between Parent and and New hood .Therefore there is improvement to resist the bending of Hood.