Section Modulus calculation and optimization
AIM
To Use the Section from Hood design and calculate the Section Modulus using the formula
S = I/y
Where,
S = Section Modulus
I = Moment of Inertia
y = distance between the neutral axis and the extreme end of the object
PROCEDURE:
The data are collected from taking the master section using the mid plane
Front crash Original:
Front crash 1.5mm offset:
Side Crash Original:
Side Crash 1.5mm offset:
SECTION VIEW PIC
SAMPLE CALCULATION
CASE1)FRONT CRASH ORIGINAL
Imin (in Meters)=1.857*10^6 m
Imax(in Meters)=7.516*10^8 m
Imin (in mm)=1857000 mm
Imax (in mm)=751600000 mm
Total Dist=878.063 mm
Y=Total Dist./2 = 439.0315 mm
S=I/Y
Smin=Imin/Y ; Smax=Imax/Y
Smin=1857000/ 439.0315 => 4229.764 mm
Smax=751600000/ 439.0315 =>1711950.053mm
Savg=(4229.764+1711950.0537)/2 =>858089.908mm
CASE2)FRONT CRASH 1.5MM
Imin (in Meters)=2.149*10^6
Imax(in Meters)=8.422*10^8
Imin (in mm)=2149000
Imax (in mm)=842200000
Total Dist=878.063
Y=Total Dist./2 = 439.031
S=I/Y
Smin=Imin/Y ; Smax=Imax/Y
Smin= 2149000/439.031 => 4894.870
Smax=842200000/439.031=>1918315.563
Savg=(4894.870+1918315.563)/2 =>961605.216
By Comparing both the cases
858089.908mm < 961605.216mm
CASE2 SIDE CRASH ORIGINAL
Imin (in Meters)=6.103*10^5 m
Imax(in Meters)=1.206*10^8 m
Imin (in mm)=610300 mm
Imax (in mm)=120600000 mm
Total Dist=486.252 mm
Y=Total Dist./2 =243.126 mm
S=I/Y
Smin=Imin/Y ; Smax=Imax/Y
Smin=610300/ 243.126 =>2510.221 mm
Smax=120600000/ 243.126 =>496039.090mm
Savg=(2510.221+496039.090)/2 =>249274.655mm
CASE2 SIDE CRASH 1.5MM
Imin (in Meters)=7.125*10^5
Imax(in Meters)=1.375*10^8
Imin (in mm)=712500
Imax (in mm)=137500000
Total Dist=486.252
Y=Total Dist./2 = 243.126
S=I/Y
Smin=Imin/Y ; Smax=Imax/Y
Smin= 712500/243.126 =>2930.579
Smax=137500000/243.126=>565550.373
Savg=(2930.579+565550.373)/2 =>284240.476
By Comparing both the cases
249274.655mm < 284240.476mm
CONCLUSION
Therefore by comparing the case-1 & case-2, as the Section modulus is directly proportional to the Moment of inertia, thus by increasing the section area the moment of inertia get increased which tends to increse in section modulus. So, higher the section area of particular part will result in average strength