Section Modulus calculation and optimization
AIM:
To calculate the section modulus of the hood panel and then optimizing the hood panel for better section modulus.
INTRODUCTION:
SECTION MODULUS:
Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members. Other geometric properties used in the design include an area for tension and shear, the radius of gyration for compression, and moment of inertia and polar moment of inertia for stiffness. Any relationship between these properties is highly dependent on the shape in question.
It is termed as the ratio of the second moment of inertia and distance from N.A (Neutral axis) to the extreme fiber. Also, it is the measure of the strength of a given member. The stress in the outermost section of the beam is computed with the help of section modulus. It is indicated by S.
MOMENT OF INERTIA:
The moment of inertia of an object is a determined measurement for a rigid body rotating around a fixed axis. The axis might be internal or external, and it can be fixed or not. However, the moment of inertia (I) is always described in relation to that axis.
The moment of Inertia depends on the distribution of the mass around its axis of rotation. MOI varies depending upon the position of the axis that is chosen. That is, depending on the location and direction of the axis of rotation, the same item might have various moment of inertia values
Case study 1:
Section modulus calculation:
S=l/y
S = Section Modulus
I = Moment of Inertia
y = distance between the neutral axis and the extreme end of the object


Section modulus calculation of hood assembly design :-

Moment of Inertia,
- M1=6.52x10^-7 m^4 (Min)
Converting m^4 to mm^4
- 1m^4=10^12 mm^4
So Moment of inertia ,
- I= 6.52x 10^5 mm^4
- y= Total length /2
- y=478.032/2
- y= 239.016 mm
Section modulus = I/y
= 6.52x 10^5 / 236.016
Section modulus=2762.525 mm^3 (MINIMUM)
Case study 2:
Optimized Section modulus calculation of hood assembly design :-

CALCULATION:-
Moment of Inertia,
- M1=6.665x10^-7 m^4 (Min)
Converting m^4 to mm^4
- 1m^4=10^12 mm^4
So Moment of inertia ,
- I= 6.665x10^5 mm^4
- y= Total length /2
- y=478.032/2
- y= 239.016 mm
Section modulus = I/y
= 6.665x10^5 / 236.016
Section modulus = 2823.961 mm^3 (min)
How to optimize?
I have increased disatance between outer panel and inner panel 0.5mm compared to prievious section. So the section modulus strength has to be increased.
RESULT:
In this study, we take the minimum of inertia moment to analyze the minimum limit of hood deformation. Thus the section modulus of the front hood was calculated and compared with the new design.
From the result we found out that increasing the cross-section area would give a better section modulus and helps in increasing the strength of the hood.