Section Modulus calculation and optimization
AIM
To use the Section from the 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
Come up with a new section that has improved the section modulus of the previous section and mention what change you made that has increased the strength.
PROCEDURE
SECTION MODULUS
It is termed as the ratio of second moment of area and distance from N.A (Neutral axis) to the extreme fiber. Also it is the measure of strength of given member. The stress in the outermost section of beam is computed with the help of section modulus.
SECTION MODULUS 1
INTERSECTION OF INNER AND OUTER HOOD PANEL
Take an intersection of the Hood Outer and Inner Panel with reference with the plane created on the zero y-axis. Then do an extract with Tangent continuity of the outer end curve for both the hood Outer and Inner curve simultaneously. Then create points and do split on both hemming region. Draw necessary lines to close the open end curves. Finally join the curve. In order to measure Inertia we have to have a closed surface. Use Fill to create closed surface.
INTERSECTION LINES/CURVES
SURFACE TO WORK WITH MOMENT OF INERTIA
MEASURING INERTIA
Now we have a closed surface. Go to Measure Inertia 
and select Measure Inertia 2D from the popup then select the surface. Now we have got the value for the Moment of Inertia. M1 is the Minimum Principal Moment of Inertia and M2 is the Maximum Principal moment of Inertia.
Principal Moment of Inertia Values as displayed
(Min. Principal Moment of Inertia) M1 - 1.912e-006m4 ; (Max. Principal Moment of Inertia) M2 - 6.701e-004m4
Conversion of m^4 to mm^4
M1 - 1.912 x 10^(-6) m(^4)
1.912 x 10^(-6) x (10^3)^4 mm^(4)
1.912 x 10^(6) mm^(4)
M2 - 6.701 x 10^(-4) m(^4)
6.701 x 10^(-4) x (10^3)^4 mm^(4)
6.701 x 10^(8) mm^(4)
Here we choose M1 - 1.912 x 10^(6) mm^(4) Min. Principal Moment of Inertia.
Moment of Inertia I = 1.912 x 10^(6) mm^(4)
Distance between the neutral axis and the extreme end of the object y = 442.3245 mm
Formula
S = I/y
S = Section Modulus
I = Moment of Inertia
y = distance between the neutral axis and the extreme end of the object
S = 1.912 x 10^(6) mm^(4)/442.3245
(SECTION MODULUS 1) S = 4323 mm^(3)
SECTION MODULUS 2
Here we used the same intersection data. But we modify by giving a parallel curve definition offset of 0.5 outwards to the outer end curve of the outer panel.
Moment of Inertia Data
Principal Moment of Inertia Values as displayed
(Min. Principal Moment of Inertia) M1 - 2.009e-006m4 ; (Max. Principal Moment of Inertia) M2 - 7.004e-004m4
Conversion of m^4 to mm^4
M1 - 2.009 x 10^(-6) m(^4)
2.009 x 10^(-6) x (10^3)^4 mm^(4)
2.009 x 10^(6) mm^(4)
M2 - 7.004 x 10^(-4) m(^4)
7.004 x 10^(-4) x (10^3)^4 mm^(4)
7.004 x 10^(8) mm^(4)
Here we choose M1 - 2.009 x 10^(6) mm^(4) Min. Principal Moment of Inertia.
Moment of Inertia I = 2.009 x 10^(6) mm^(4)
Distance between the neutral axis and the extreme end of the object y = 442.3245 mm
Formula
S = I/y
S = Section Modulus
I = Moment of Inertia
y = distance between the neutral axis and the extreme end of the object
S = 2.009 x 10^(6) mm^(4)/442.3245
(SECTION MODULUS 2) S = 4542 mm^(3)
Comparisson
(SECTION MODULUS 1) S = 4323 mm^(3) of the existing car.
(SECTION MODULUS 2) S = 4542 mm^(3) of the new car.
Based on the section moudulus analysis we know that the new car material has more strength than the old one.