Section Modulus calculation and optimization
Aim:
To calculate the section modulus of the Hood design and improve the section of hood and calculate the section modulus and compare the cases.
Introduction:
Section modulus is defined as a geometric property of a given cross-section used in designing the flexural structures. It is purely dependent only on the cross-section of the member.
There are two types of section modulus
- Elastic section of modulus
- plastic section of modulus
Section modulus by using the formula S = I/y
S = Section Modulus
I = Moment of Inertia
y = distance between the neutral axis and the extreme end of the object
Moment of inertia:
The bending stiffness of a structural member’s cross-sectional shape.
Moment of inertia is specific to bending of the cross section of the member.
Case 1- Original Design:
In the original hood design,
From the analysis, we got minimum moment of inertia as
I min = 1.590294342e+04[mm^4] and We know y = 439.5mm from measuring the distance between the neutral axis and the extreme end.
Therefore, S= I/y
I min = 1.590294342e+04[mm^4]
y = 439.5mm
S = 1.590294342e+04[mm^4] / 439.5
Section Modulus S min= 36.18 mm^4
Case 2- Modifying the original Hood design:
Changes made to increase the strength of the hood:
Improving the section modulus by modifying the design by offsetting the outer panel by 2 mm in outward direction.
From the analysis, we got minimum moment of inertia as
I min =1.689915388e+04[mm^4]
And y = 439.5mm.
Therefore, S min = 1.689915388e+04[mm^4] / 439.5
S min = 38.45 mm^4.
Table
| Case | Design | Moment of Inertia(min) | Section modulus |
| #1 | Original hood | 1.590294342e+04[mm^4] | 36.18 mm^4 |
| #2 | Modified hood | 1.689915388e+04[mm^4] | 38.45 mm^4 |
Conclusion
Thus, Section modulus of the hood is calculated and section of hood is improved to increase the strength and section modulus is calculated again.