SECTION MODULUS

OBJECTIVE :-

• To calculate the section modulus of hood
• To come up with new section that has new section modulus.

MATERIAL OF THE HOOD :-

Given :- stainless steel AISI 302 -cold rolled (maximum strength) y=520 MPa

Section Modulus:- Ratio of total moment resisted by the section to the stress in the extreme fibre.It gives us an idea about how much of load that the structure can take and if the section modulus increases the moment of resistance increases and hence its load bearing capacity increases that is higher the section modulus higher will be the resistance of bending so our main motive is to increase the section modulus .

Section Modulus (S) = I/y(max)

I= Moment of inertia.

Y= Distance from neutral axis to outer most fibre.

In the above diagram i measure the Moment of inertia of previously designed hood and the result is :-

• M1(Min)= 3.64x10^5mm^4
• M2(Max)= 1.259x10^8mm^4

The above diagram shows the distance between the outer most edge of the hem

and to find out y(distance from neutal axis to the outer most edge of the fibre) = 477.887/2 =238.9435

Section modulus (S)= I(max)/y =1.259X10^8/238.9435 = 526902.8034 mm^3.

Now to increase the moment of inertia of the hood i increase the offset distance between the hem and hood inner pannel by 1.2 mm and made embosses.

The above diagram shows the new Moment of inertia

M1(Min) = 4.22x10^5mm^4

M2(Max) = 1.267x10^8mm^4

And the new section modulus is S=1.267x10^8 /238.9435 =530250.875mm^3.

As we can see that after changing the offset distance between hem and inner panel by 1.2mm and creating emboss section moudulus of hood increases by 3348.072mm^3 therefore i can conclude that by increasing the offset distance we can increase the section modulus of Hood.