Section Modulus calculation and optimization

Aim

To compute the section modulus of the hood design, And also optimise the section to improve the section modulus

Section Modulus

It is the direct measure of strength of steel. steel section having higher section modulus will be stronger and harder to bend

section modulus S = I/Y

I - Moment of Inertia

Y - distance between the neutral axis and the extreme end of the object

Procedure

Calculating the section modulus of the hood design

Hood design

Take a interception of the hood design with respect to Z-Y plane

Then extract top curve from outer panel and bottom curve from inner panel. Then trim both curves together into a single curve

Then create a surface using fill option on the curve

Use the measure inertia command to check the inertia of the section

Minimum inertia - 5.917*10⁵ mm⁴

Maximum inertia - 1.42* 10⁸ mm⁴

Distance between the neutral axis and the extreme end of the objectistance between the neutral axis and the extreme end of the object

Y - 483.028/2 = 241.514 mm

Section Modulus - (5.917*10⁵)/241.514 = 2,449.961 mm³

After optimising the section

The bottom surface of inner panel is offseted 1.5mm towards the bottom

Minimum inertia - 6.013*10⁵ mm⁴

Maximum inertia - 1.435* 10⁸ mm⁴

Y - 241.514 mm

Section Modulus - (6.013*10⁵)/241.514 =2,489.711 mm³

Conclusion

Section Modulus after optimisation (2,489.711 mm³) is greater than Section Modulus before optimisation (2,449.961 mm³). so the section after optmisation will have greater strength than the section before optimisation. This increase is obtained by decreasing the distance between inner and outer panel