Section Modulus calculation and optimization

Section modulus for hood design

Section modulus

Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members. Other geometric properties used in design include area for tension and shear, radius of gyration for compression, and second moment of area and polar second moment of area for stiffness.

S = I / y

Where,

I is the second moment of area

Y is the distance from the neutral axis to any given fibre

Why do we calculate 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.

CASE 1

My hood design

MOI(max)=8.915143x10^7mm^4

MOI(min)=2.898892x10^5mm^4

Sectional modulus equation

S=I/Y

Y=total distance /2

Y=879.1216/2

Y=439.560mm

I=MOI(min) is considered

S=2.898892x10^5/439.560

S=65.949mm^3

Section modulus for given section S=65.949mm^3.

CASE 2

This case increase thickness of outer panel is 0.75mm to 1mm

S=I/Y

I=2.8097xe^5(mm^4)

Y=439.560mm

S=2.8097xe^5/439.560

S= 63.904mm^3

Section modulus for given section S= 63.904mm^3.

Conclusion

In this sectional modulus case 2 value is lower than case 1.

It also calculated and found that sectional modulus increased with increase in cross section area.