Section Modulus calculation and optimization

Section Modulus is the geometric property of a given cross section used in the design of flexural members. It depends only on the cross sectional shape of the beam or structure.

an asymmetric section has two different values of section of modulus the is above and below the centroid of the cross section, namely Smin and Smax

Aim : -

To determine the section modulus of a previously designed hood and to come up with a beeter setion to improve section modulus

formulae to be used : Section Modulus S = I/y

Where, I = Moment of inertia & y = the distance from the centre to the extreme end

Procedure: -

FIRST SECTION

In this first iteration section modulus

S1 = m1/y

= 2.212*10^6mm4 / 440.013mm

= 5027.124 mm3

SECOND SECTION (AFTER INCREASING THE CROSS SECTION)

In this second iteration section modulus

S2 = m1/y

= 2.357*10^6mm4 / 441.013mm

= 5344.513 mm3

The value M1 is considered in both the cases. This is minimum moment of inertia because bending moment is inversely proportional to moment of inertia. . So more the area moment of inertia, less will be the bending.

Conclusion: -

By comparing the S1 & S2 values, we can notice that the section modulus can be increased the increasing the depth of the bonnet, or in other words bringing a change in the cross section. Hence the strength also increases with the increase in section modulus increase, as we saw in the case of second iteration S2.