Section Modulus calculation and optimization
SECTION MODULUS CALUCULATION AND OPTIMIZATION
SECTION MODULUS:
It is a way of quantifying a cross-section of a given geometry. It is directly proportional to the area moment of inertia of the cross-section. Higher the section modulus, the more the moment of inertia, more stiffness and thus more resistance to deformation and bending. Section modulus can be improved by varying the geometry of the cross-section. In other words, stiffness can be improved by just improving the geometry without the need for adding extra materials.
Section Modulus(S) Calculation:
S= I / Y
Where, S – Section Modulus,
I – Area Moment of inertia or Second Order Moment of inertia.
Y(Max)- Distance of Extreme Layer from Neutral Axis.
The following are few iterations performed over the Car Hood or Bonnet cross -section.
Section#:1
Type : Hollow
CG:(0.000000000, 750.687224941, -931.258170844) [mm]
MOI (max):8.196668263e+05[mm^4]
MOI (min):5.353424185+03[mm^4]
Principal Directions:
Max:(0.000000000, 0.979920583, 0.199388193)
Min:(0.000000000, -0.199388193, 0.979920583)
Section Length:2.046349327e+03[mm]
Section Area:40.926969966[mm^2]
Distance of Extreme Layer from Neutral Axis (Y) - 476.4/2=238.2mm
Section Modulus (s) = I / Y =5353.424185/238.2=22.47[mm^3]
from section -1 minimum moment of inertia and extreme distance of the layer we got the section modulus value is (S)=22.47mm^3
Section#:2
Type : Hollow
In this section modulus to increase of inner panel distance from the previous section#:1. Offset of the inner panel 0.5mm
CGC:(0.000000000. 750. 433067368, -931.318829756)[mm]
MOI(Max):8.173668722e+05[mm^4]
MOI[Min):5.541067090e+03[mm^4]
Principal Directions:
Max:(0.000000000, 0.979918955, 0.199396194)
Min:(0.000000000, -0.199396194, 0.979918955)
Section Length:2.044137465e+03[mm]
Section Area:40.882731199[mm^2]
Distance of Extreme Layer from Neutral Axis (Y) - 476.4/2=238.2mm
Section Modulus (s) = I / Y =5541.0670/238.2=23.2622[mm^3]
from section -2 minimum moment of inertia and extreme distance of the layer we got the section modulus value is (S)=23.2622[mm^3]
CONCLUSION:
Different section, as shown above, were tried in order to achieve a higher moment of inertia. It is observed that increasing the gap between the inner and outer panels has resulted to improve the section modulus. Hence it is the best to add more geometric features to the master section to more the stiffness of section. However, this could result in an increase in manufacturing cost