Section Modulus calculation and optimization

SECTION MODULUS CALCULATIONS AND OPTIMIZATIONS

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

INTRODUCTION

SECTION MODULUS

• Section modulus is a direct measure of strength of any sectional area of an object about a reference axis
• Strength is nothing but capable of supporting greater loads so higher the strength it has a high capable of supporting greater loads , this strenth can be measured directly from section modulus formula ,the representation of section modulus is with a symbol 's'.
• There are two types of section modulus elastic section modulus and plastic section modulus.
• It is signinficant for beam and flexural member design
• more the section modulus , the more the member is resistant to the bending of the beam
• If two beams are made of the same material and comparing the section modulus of two beams , the beams with larger section modulus have more strength comparing to the other one.
• S=I/Y
• The unit of section modulus is mm^3

Where 'I' is the moment of inertia and 'Y' is the total distance from the reference line to one of the extreme end of an object.

MOMENT OF INERTIA

Moment of of inertia is nothing but offering resistance aganist of moment ,bending or twisting , that is if we applied any external load on the body , how much resistance its offering to deform. so the higher the value of moment of inertia it have higher resistance to deform under certain load,ie, the moment of inertia is directly proportianal to the strength of the material.

By the help of moment of innertia we can measure the strength of the material.

SECTION MODULUS AND OPTIMIZATION OF HOOD

CASE -1

In this case the intersection of the hood assembly is taken and moment of inertia analysis is done on the NX - software and the following result are obtained from the analysis.

Here the value obtained are,

Moment of inertia (MAX) =1.547776571 x 10^7 mm^4

Moment of inertia (MIN) = 9.371994736 x10 ^4 mm^4

Total length 2Y= 486.6387mm

Y= 486.6387/2

Y= 243.3193

Section modulus 's' = I/Y

=9.3719947 x10^4 / 243.3193

=385.17265mm^3

HOOD DESIGN OPTIMIZATION

In this case the innerpanel depth is increased by 0.5,

Here the value obtained are,

Moment of inertia (MAX) = 1.5426833x10^7mm^4

Moment of inertia (MIN) = 9.693952x10^4mm^4

Total length 2Y= 486.6387mm

Y= 486.6387/2

Y= 243.3193

Section modulus 's' = I/Y

S = 9.693952x10^4/243.3193

=398.40456mm^3

CONCLUSION

Hence when comparing case 1 and case 2

The section modulus value of case 2 is higher than the case 1 ,as we increase the moment of inertia and section modulus gradually increases, ie, the strength of the material also increases by increasing the cross section .