Section Modulus calculation and optimization

Section modulus

Section Modulus is a phenomena which is used to calculate the bending stresses in any structural member. where this is denoted by s and fourmula is s =I/y .

• where
• S = section modulus
• I = moment of inertia
• y = distance from the neutral axis .

Section Modulus study

to find better section modulus for our hood panel we will consider 3 cases and will find which will have better section modulus since better section modulus means better bending stress resistance we need to find better section modulus as per data .

case 1

in case 1 we connected all the remaining part of our hood and remove the thicken part of our outer and inner panel as well after doing section intertia analysis we get these data .

Type: Hollow
CG: (-0.003125876, 744.653101730, 0.000000000) [mm]
MOI (Max):4.886111065e+06[mm^4]
MOI (Min):1.254285498e+04[mm^4]
Principal Directions:
Max: (-0.000002013, 1.000000000, 0.000000000)
Min: (1.000000000, 0.000002013, 0.000000000)
Section Length:3.651414618e+03[mm]
Section Area:73.028150022[mm^2]

since section modulus - S=I/Y

I = 3.80950148 x 10^4

Y = 441.2440

so S would be - S=3.80950148 x 10^4 /441.2440

S = 86.33548512840968

case 2

in case 2 we offset inner panel downwards by 0.5 mm and connected all the remaining part of our hood and remove the thicken part of our outer and inner panel as well after doing section intertia analysis we get these data .

Type: Hollow
TCG: (0.002242368, 744.399351086, 0.000000000) [mm]
MOI (Max):4.876916838e+06[mm^4]
MOI (Min):1.277541285e+04[mm^4]
Principal Directions:
Max: (0.000005464, 1.000000000, 0.000000000)
Min: (1.000000000, -0.000005464, 0.000000000)
Section Length:3.648986224e+03[mm]
Section Area:72.979603621[mm^2]

I = 3.87271726 X 10^4

Y = 441.2440

s = 87.76815684745855

case 3

in case 2 we offset inner panel downwards by 0.5 mm , increasing depth of emboss by 10mm each side and connected all the remaining part of our hood and remove the thicken part of our outer and inner panel as well after doing section intertia analysis we get these data

Type: Hollow
CG: (0.018096203, 743.071082784, 0.000000000) [mm]
MOI (Max):4.980847025e+06[mm^4]
MOI (Min):1.416044596e+04[mm^4]
Principal Directions:
Max: (0.000010606, 1.000000000, 0.000000000)
Min: (1.000000000, -0.000010606, 0.000000000)
Section Length:3.714854279e+03[mm]
Section Area:74.296951345[mm^2]

I = 4.24920829 X 10^4

Y = 441.2440

s = 96.3006474875579

CONCULSION

• after comparing the values of case 1 and 2 section modulus is increased of hood by 1.6594239517%
• after comparing the values of case 2 and 3 section modulus is increased of hood by 9.7216245009%
• after comparing the values of case 1 and 3 section modulus is increased of hood by 11.5423714181%