Section Modulus calculation and optimization
SECTION MODULUS CALCULATION AND OPTIMIZATION
Section Modulus:-
It is the ratio of moment of inertia of section about the neutral axis to the distance of the outer layer from the neutral axis.
- Its denoted by 'S'
- Its units are mm3 or m3
S = I/Y------------(1)
I= Moment Of Inertia
S= Section Modulus
y=The distance between the neutral axis and the end of the object.
Section Modulus Calculation for Hood Design
Initial Hood design and its moment of inertia:-
The hood which we are already created is imported and the section inertia analysis is done. We have to make sure that the curve obtained is of a single/closed curve. As shown below image.
First, we go to the analysis >Section inertia analysis > select the curve
The moment of inertia is obtained. Show on the below image.
From the above fig,
we took a moment of inertia values.
MOI(max)=4.817752445e+006mm4
=4817752.445mm4
MOI(min) = 1.391358770e+004mm4
= 13913.5877mm4
Section Modulus , S = I/Y
Y = 440.3 mm
we are taking mim moment of inertia
S= I/Y
S= 13913.5877mm4/440.3mm
S= 31.6mm3
After Hood Design Modifications:-
The hood outer panel curve is offset to 2mm outwards and section inertia analysis is done as same as in the first step.
MOI(max)= 4.801328222e+006mm4
=4801328.222 mm4
MOI(min) =1.481753975e+004mm4
=14817.753975 mm4
y= 440.3 mm
As per the section Modulus
here I is the moment of inertia
Y is the distance between the neutral axis and the end of the object
S=I/Y
we know that
Section modulus is directly proportional to the moment of inertia
S= I/Y.
S= 14817.7539/440.3
S= 33.6537 mm3
Result
Therefore, a small modification in section area results in a variation of section modulus.
Before Modification the hood the section modulus is
S= 31.6mm3
After Modification the hood design the section modulus is
S= 33.6537 mm3
Here we see after modification of the hood design the section modulus is higher than the before modification of the hood design. As we increase the area of cross-section, the moment of inertia and section modulus increase which means the strength and load capacity of the material also increase.