Section Modulus calculation and optimization

Section Modulus : Section modulus is the ratio of area moment of inertia about the neutral axis to the length from the neutral axis to the outer most fibre. The section modulus is a geometric property of a cross-sectional shape that relates to its ability to resist bending. Components like body panels, frames, and chassis need to be designed to withstand various loads and stresses experienced during vehicle operation. For that it should have a minimum section modulus. More the section modulus, the more load it can withstand.

Z = I/y

where,

Z = Section modulus

I = Area moment of inertia

y = length from the neutral axis to the outer most fibre

From the hood design :

A plane is created in the centre of the hood. An intersecting curve is created which intersects the plane and the hood assembly. This curve is projected in asketch on the same plane and is made into a closed curve . The section inertia analysis of this curve is done.

Minimum moment of inertia is considered for analysis

From the section inertia analysis of the hood section,

I= 14371.938 mm4

y= 876.458 mm

Therefore, z= I/y = 16.39 mm3

Improving Section modulus : For improving the section we create a new section by offsetting the lower portion

From the section inertia analysis of the new improved section,

I= 14596.39 mm4

y= 876.458 mm

Therefore improved section modulus, z= I/y = 16.65 mm3