Section Modulus calculation and optimization

Section Modulus of an Hood

Section modulus is a direct measure of strength of any sectional area of an object about a neutral axis

Strength is nothing but capable of greater loads, This Strength directly measured by section modulus by given formula,

Formula for Section modulus

S=I/y……………………………………………………………………………………………... (1)

Where S= section

I=moment of inertia

Y= distance between the neutral axis and the extreme end of the object.

Moment of inertia is nothing but offering resistance against of moment, bending, twisting i.e., if we applied any external load on the body, how much resistance its offering to tend to deform. So higher the value moment of inertia higher will be resistance to carry the load.

We can say moment of inertia is directly proportional to the strength of the material.

MOMENT OF INERTIA(I) = 8.0814 X 10^5 mm⁴ and min(I)= 3.4084 X 10^3 mm⁴

Y=476.6/2=238.3

S=?

By solving above eq (1) we get,

S(max)=3.391 X 10^3 mm²

S(min)=1.279 X 10^3 mm²

Offsetting the curve by 0.5 mm for a tial

I(max)=8.0318 x 10^5 mm⁴

I(min)=3.091 x 10^3 mm⁴

By solving using eq (1)

We get, S(max)=3.370 X 10^5 mm²

S(min)=1.297 x 10^3 mm²

Comparing the both hoods of its maximum and minimum value,

As we see the minimum values of strength (1.279 X 10^3 mm² and 1.297 x 10^3 mm²) , the 2^nd trial the strength is increased so section area is also increased .

For maximum values of strength (3.391 X 10^3 mm² and 3.370 X 10^5 mm²), when we offsetting the value of 0.5 mm, the inertia between max to min to comes nearly to mean.

Its not only depend on cross section area, but also depends on material thickness where for automobile we keep FOS between +3 and above.

Conclusion:-

Hence by comparing the trials we actually concluded the strength of the material.

(Software used Siemens NX)