Section Modulus calculation and optimization
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. It is indicated by S.
Section modulus is indicated as follows:
Here, I is “moment of inertia” and y is distance from “neutral axis” to top or bottom of fiber.
Unit of a “section modulus” is in.3(mm3).
Section modulus depends only on the cross section shape of the beam. Cross section shapes like rectangular, square, circular, I section and T, composite section etc.
For symmetric sections, the value of “section modulus” is for both above and below of centroid of the fiber.
An asymmetric section has two values for top and bottom of the fiber due to different distance from centroid to the top and bottom of the material, the maximum “section modulus” is S m ax and the minimum section modulus is S min.
• It is significant for beam and flexural member design.
• More the section modulus, more the member is resistant to bending of the beam.
• It is easier to calculate stresses in beam and an exact measure of strength of steel.
• If two beams are made of same material and comparing the “section modulus” of two beams, the beam with bigger section modulus will be tougher and more capable to withstand larger loads.
Use the Section from your Hood design and calculate the section modulus using the formula S = I/y
Type1: Hollow
CG: (0.000543150, 744.939380431, -931.505927891) [mm]
MOI (Max):4.77897527e+06[mm^4]
MOI (Min):1.41743857e+04[mm^4]
Principal Directions:
Max: (-0.000157763, 0.985088706, 0.172047136)
Min: (0.999999988, 0.000155411, 0.000027143)
Section Length:3.731163346e+03[mm]
Section Area:74.623289931[mm^2
Y=439.6MM
I=1.4174.3857MM^4
SECTION MODULUS (S) =32.2438255^3
Type2: Hollow
CG: (0.022712748, 743.874651266, -931.691884346) [mm]
MOI (Max):4.768701938e+06[mm^4]
MOI (Min):1.497257794e+04[mm^4]
Principal Directions:
Max: (-0.000154279, 0.985088706, 0.172047136)
Min: (0.999999988, 0.000151978, 0.000026543)
Section Length:3.728467271e+03[mm]
Section Area:74.569195072[mm^2
Y=439.6MM
I=14972.57794MM^4
SECTION MODULUS (S) =34.0595495MM^3
CONCLUSION:
In this study We take the minimum of inertia moment to analyze the minium limit of hood deformation thus ths section modulus of the front hood was calculated and compared with the new design.
from the result we found out that increasing the the cross section area would give a better section modulus and helps in increasing the strength of hood .