Section Modulus calculation and optimization
Section Modulus calculation and optimization
Objective
To calculate the section modulus of designed Hood
Aim
- Calculate the moment of inertia
- Calculate the Distance between the centroid (Nuetral Axis) and the extreme end of the component.
- Calculate the section modulus.
Calculation
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.
It includes the idea that most of the work in bending is being done by the extreme fibres of the beam, ie the top and bottom fibres of the section. The distance of the fibres from top to bottom is therefore built into the calculation.
The elastic modulus is denoted by Z. To calculate Z, the distance (y) to the extreme fibres from the centroid (or neutral axis) must be found as that is where the maximum stress could cause failure.
S = I/Y
S - Section Modulus
I - Moment of Inertia
Y - Distance between the centroid (Nuetral Axis) and the extreme end of the component.
CASE 1
Here, the original Hood is taken into consideration. No changes were made.
Then the moment of inertia is found by using section inertia analysis in NX cad. The values are obtained as follows
Then the distance between the nuetral axis and the end of part is measured as below
Therefore,
S = I/Y
= (1.536 X 10^4) / 438.005
= 35.06 mm^3
Case 2
The section modulus to be improved by doing some modification. Here I modified the distance between the Outer Panel and inner panel (from 2.17 mm to 3 mm) and the Geometric shape of Inner panel.
Then the moment of inertia value is obatined using section inertia analysis as below
Therefore
S = I / Y
= (2.119 X 10^4) / 438.005
= 48.37 mm^3
Conclusion
Thus the section modulus of Hood is calculated and values are improved by changing the design of hood. The section modulus is improved from 35.06 mm^3 to 48.37 mm^3.