Section Modulus calculation and optimization
Aim :
To calculate the section modulus of the hood and optimize the design to have an improved section modulus. Section modulus:- Section modulus is a direct measure of the strength of any cross-sectional area of an object about a reference axis. The formula of section modulus is given by, S=I / Ymax Where, I = Moment of inertia (mm^4).
Section Modulus:
Section Modulus is the force resisting against the Moment, Bending or Twisting. So, the Higher the Section Modulus, the higher will be the resistance to deformation.
Using the Section from your Hood design and calculating the Section Modulus using the formula
S = I/y
Where,
S = Section Modulus
I = Moment of Inertia
y = distance between the neutral axis and the extreme end of the object
Here is the sectional modulus of hood design before optimization
The moment of inertia is calculated by NX-CAD software.
Imax – 8.356245596 x 10^5 (mm^4)
Imin – 6.473045094 x 10^3 (mm^4)
Y = Total length / 2
= 482.74/2
=241.37 mm
section modulus for max. = 8.356245596 x 10^5 / 241.37
= 3.462 x 10^3
section modulus for min. = 6.473045094 x 10^3 / 241.37
= 0.2681 x 10^3
So for this hood design section modulus range from 3.462 x 10^3 mm^3 to 0.2681 x 10^3 mm^3
Design Optimization:
The design is optimized by increasing the thickness of the outer hood panel from 0.75-1mm.
Imax – 8.405318 x 10^5 (mm^4)
Imin – 6.570635 x 10^3 (mm^4)
Y = Total length / 2
= 482.74/2
=241.37 mm
section modulus for max. =8.405318 x 10^5 / 241.37
= 3.482 x 10^3
section modulus for min. = 6.570635 x 10^3 / 241.37
= 0.2722 x 10^3
So for this hood design section modulus range from 3.482 x 10^3 mm^3 to 0.2722 x 10^3 mm^3
So, from this data, we can conclude that if the section modulus is increased from 3.462 x 10^3 mm^3 to 3.482 x 10^3 mm^3 by increasing the Thickness of the Hood.


