Section Modulus calculation and optimization

INTENT: To calculate the Section modulus of the hood design by using sectioning on it

Section modulus

Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members, it is also referred to as the Polar Modulus or the Torsional Sectional Modulus. Other geometric properties used in design include area for tension and shear, 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. Equations for the section moduli of common shapes are given below. There are two types of section moduli, the elastic section modulus, and the plastic section modulus. 

S=I/Y

Here,

S = Section modulus

I= Moment of Inertia (Unit mm 4)

Y= Distance from the Neutral axis to the extreme end (unit mm)

The Unit of a “section modulus” is (mm3)

PROCEDURE :

First Taking out the intersection of the inner panel and outer panel of the model as shown below Section modulus is the direct measure of the strength of the steel. Bending a steel section that has a larger section modulus than another will be stronger and harder to bend.

Section modulus is a geometric property for a given cross-section used in the design of flexural members

First design study:

The more section modulus, the more the member is resistant to the bending of the beam. If two beams are made of the same material  and comparing the section modulus of the two beams the beam with a bigger section modulus will be tougher and more capable to withstand larger loads

S=I(min.)/Y ;2Y=800mm ; I(min.)= 3.406*10^-6m^4

S=3.406*10^6/400= 8515 mm^3

 The intersection for the offset of 1 mm of the outer panel is shown below

Hood Design Optimization :

S=4.413*10^6/400=11032.5 mm^3

Increasing the gap between the outer and the inner panel leads to an increment in the section modulus, so resistance to bending will also be get increased due to this, the strength of the hood will increase.

Now the change % will come as 

S = (11032.5 - 8515)/8515*100 = 29.56547 % (inc.) in the section modulus.