Section Modulus calculation and optimization

REPORT ON SECTION MODULUS

Aim

The aim of this report is to calculate the section modulus of the designed Hood Assembly and also make changes to improve section modulus.

Introduction

Section modulus - It is defined as the ratio of area moment of inertia about neutral axis and to the distance of outermost fiber from the neutral axis.

Formula for the section modulus -

Z = I / Y

Where,

Z = Section Modulus

I = Area Moment of Inertia

Y = Distance from neutral axis to the outermost fiber

So, here the distance from neutral axis is always constant so that to improve the section modulus we need to improve area moment of inertia.

So as you can see in the above image, in case 1 the width of cross-section is b and depth is d. so here area moment of inertia will be -

I = bd^3 / 12

in case 2 the width of cross-section is d and depth is b. so here area moment of inertia will be -

I = db^3 / 12

So as you can see in the above image b > d for the depth of the cross-section. so here the section modulus for case 2 will be more than case 1.

Therefore, we get that in case to improve the section modulus we need to improve depth of the cross-section.

Now create a section from designed Hood Assembly -

The distance between the outermost fiber you can see in the given image below -

Here the distance between outermost fiber is 878.76 mm. so the distance of outermost fiber from the neutral axis (Y) will be 439.38 mm.

Now we create a section from designed Hood Assembly and do section modulus analysis for that section.

In above image you can see the minimun moment of inertia is calculated as 2.90328242

so here the section modulus will be -

Z = I / Y

= 2.90328242 / 439.38

= 0.00660767

Now we make changes in section of designed hood assembly and calculate the moment of inertia.

as you can see in the above image, here the minimum moment of inertia is 2.93958145

so here the section modulus will be -

Z = I / Y

= 2.93958145 / 439.38

= 0.00669029

Therefore, we can see that the section modulus is increased by make changes in section of Hood Assembly.

Conclusion

Hence, we discussed about the section modulus and calculate the section modulus from Designed Hood Assembly. We also discussed about the improvement of section modulus.