Section Modulus calculation and optimization
Aim
1. To calculate the Section Modulus of the Hood
2.Come up with a new section that has an improved Section Modulus compared to the previous one.
Introduction
Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members.
- Elastic Section Modulus
- Plastic Section Modulus
Formula for calculating Section Modulus:
S or Z = I/y
S or Z - Section modulus of materials
I- Moment of inertia
y- Length of extreme fiber from the neutral axis
For symmetrical sections the value of Z is the same above or below the centroid.
For asymmetrical sections, two values are found: Z max and Z min.
Significance of Section modulus
The section modulus of the cross-sectional shape is of significant importance in designing beams. It is a direct measure of the strength of the beam. A beam that has a larger section modulus than another will be stronger and capable of supporting greater loads.
Desgin #1
Section modulus of Hood
Calculating movement of inertia in NX Cad by projecting a intersecting curve in middel of hood and joining the edges.
Section report
Imax =8.28 x 10^5 mm^4
Imin= 9.77 x 10^3 mm^4
y= 242 mm
Zmax= Imax/y
= 8.28 X 10^5/242
= 3408.389 mm^3
Zmin= Imin/y
=9.77 X 10^3/242
= 40.21 mm^3
This is the result of section modulus our initial hood design.
Desgin #2 Modified Hood
to increase the section modulus i offset the hood outer pannel by 3 mm
here is the setion report
Zmax= Imax/y
= 8.91 X 10^5/242
= 3667.72mm^3
Zmin= Imin/y
=1.16 X 10^4/242
= 47.75 mm^3
Hence the section modulus of our hood has been increased as compared with the previous value which is 40.21 mm^3 and the new value is 47.75 mm^3.
Percentage increase in section Moudulus= 15.79%