Section Modulus calculation and optimization

                              SECTION MODULUS CALCULATION AND OPTIMISATION

Use the Section from  Hood design and calculate the section modulus using the formula S =I/y

S = Section Modulus

I = Moment of Inertia

y = distance between the neutral axis and the extreme end of the object 

SECTION MODULUS:

Section Modulus is a geometric property used to calculate the bending stresses in a structural member.

The section modulus of the cross-sectional shape is of significant importance in designing structures. It is a direct measure of the strength of the structure

A structure that has a larger section modulus than another will be stronger and capable of supporting greater loads.

Section modulus (S) = I/y

Where,

I = Moment of inertia in (mm⁴)

y = Distance between the neutral axis and the extreme end of the object (mm)

MOMENT OF INERTIA:

Moment of inertia is defined as the quantity expressed by the body resisting angular acceleration which is the sum of the product of the mass of every particle with its square of a distance from the axis of rotation

NEUTRAL AXIS:

The neutral axis is an axis in the cross-section along which there are no longitudinal stresses or strains. If the section is symmetric, isotropic, and not curved before a bend occurs, then the neutral axis is at the geometric centroid. All fibers on one side of the neutral axis are in a state of tension, while those on the opposite side are in compression.

Now to calculate the section modulus from the hood design:

Take the front section since we are dealing with a frontal crash. For that create a datum plane on the curve and at a half distance of the hood.    

Find the intersection curve between the newly created datum plane and the hood. Measured the distance between the extreme ends of the hood        

Section 1:

Calculating section modulus for the hood design:

I (MOI) = 1.317 x 10⁴ mm⁴

y  =879.16/2 =439.58mm

S = (1.317 x 10⁴) / 439.58  =  29.96mm³   

Section 2:

^{The outer line of the inner panel is offset to .5 mm downwards. In other words, the depth of the inner panel is increased to notice the changes in the section modulus.}

I (MOI) = 1.333 x 10⁴ mm⁴

y  =879.16/2 =439.58mm

S = (1.333 x 10⁴) / 439.58  =  30.32mm³

^,

The section modulus of the section was calculated.comparing two sections,

When the depth of the section is increased, it is noticed that the section modulus increases, hence the section's load-bearing capacity.