Section Modulus calculation and optimization

What is Section Modulus?

Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members. Section modulus is defined as S = I / y, where I is the second moment of area and y is the distance from the neutral axis to any given fiber, usually the extremity of the geometry. This property is used to determine the maximum bending moment before failure, or the yield moment of the design when the yield strength is known.

The Section modulus analysis as analyzed between the outer and inner hood panel:

Objective:

To try and increase the section modulus so that the yield moment is higher for designed part.

We can change the geometry to increase the cross section as section modulus is directly proportional to the area moment of inertia.

New cross section sample:

with 2mm offset to increase area.

Improved moment of inertia:

Calculations :

2y = 880.165 mm
y = 440.0825 mm
MOI = 1.439423737 * 10^4 mm^4
Section Modulus = MOI/y = 32.70804 mm^3
new MOI = 1.735710546 * 10^4 mm^4
new Section Modulus = 39.44057 mm^3