Section Modulus calculation and optimization

Aim:

To find the section modulus of the hood and optimization to improve the overall section modulus.

Objective:

Use the section from your Hood design and calculate the section modulus using the formula S= I/y.

Section Modulus:

The section modulus (S) is the geometry property of the cross-section used for designing beams and flexural members. It does not represent anything physically.

Where,

S=I/y

S= Section modulus (mm^3)

I = Moment of inertia of the section to the stress at the end of the object (mm^4)

Y= Distance between the neutral axis and the end of the object (mm).

CASE_1 :

using the 'Measure inertia' tool in Catia, we have to find the minimum & maximum moment of inertia (M1 & M2 respectively). Here M1 denotes the 'I' value in the section modulus formula we are going to use.

Minimum Value = 1.978e-006 m^4

= 1.978e-006 x 10^12 mm^4

= 1.978e006 mm^4

Maximum Value = 6.643e-004 m^4

=6.643e-004 x 10^12 mm^4

= 6.643e008 mm^4

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

Y =888.74/2

=444.37

Hence section modulus,

S = I/Y

= 1.978e006 / 444.37

= 4451.2 mm^3

CASE_2 :

Now, in order to improve the strength, I tried changing the distance between an inner and outer panel of the hood assembly. So, I offset the outer contour of the inner panel by0.1mm (outwards).

The result is shown below.

Inertia of Part

Minimum Value = 2.085e-006 m^4

= 2.085e-006 x 10^12 mm^4

= 2.085e006 mm^4

Maximum Value = 6.964e-004 m^4

= 6.964e-004 x 10^12 mm^4

=6.964e008mm^4

Y = Distance between the neutral axis and the extreme end of the object

Y = 889.356/2

=444.678

Hence section modulus,

S = I/Y

= 2.085e006/ 444.678

=4,688.78 mm^3

CONCLUSION

The section modulus of the hood is 4451.2 mm^3 and by increasing the 0.1 mm value it is 4,688.78 mm^3, Hence by increasing the value the section modulus strength also increases.