Section Modulus calculation and optimization

Aim 

To calculate the section modulus of the previously designed hood for analyzing its strength and also optimizing the design to see the difference in the bending strength of the hood. Higher the section modulus of a structure, the more the resistive it becomes to bending.

Scection Modulus

The elastic section modulus is defined as S = I / y, where I is the second moment of area (or area moment of inertia, not to be confused with moment of inertia) and y is the distance from the neutral axis to any given fibre. It is often reported using y = c, where c is the distance from the neutral axis to the most extreme fibre, as seen in the table below. It is also often used to determine the yield moment (My) such that My = S ⋅ σy, where σy is the yield strength of the material.

S=I/Y

Here,

S = Section modulus

I= Moment of Inertia (Unit mm 4)

Y= Distance from Neutral axis to the extreme end (unit mm)

The Unit of a “section modulus” is (mm3)

Create a plane in the midlde of the hood 

Use curve instersection tool to get the section of the hood 

Moment of inertia(max) = 9.036856069×10^7×mm^4

Moment of inertia(min) = 2.762809514×10^5×mm^4

Y=876.33/2=438.165 mm

Hood Design Optimization

By increasing the depth of the inner panel by 0.5 mm we can imporve the mimum strength 

Moment of inertia(max) = 9.052903817×10^7×mm^4

Moment of inertia(min) = 3.017460692×10^5×mm^4

Y=876.33/2=438.165 mm

Conclusion

So, here the difference can be seen in the moment of inertia and the change in the section modulus can be seen by the change in the design(depth).