Section Modulus calculation and optimization
SECTION MODULUS:
The Section modulus is a measure of a beam's ability to resist bending stress. It is the ratio of area moment of inertia about the neutral axis and to the distance of outermost fiber from the neutral axis.
The section modulus can be expressed as: Z=I/Y
The section modulus is denoted bt the sysmbol 'Z' and has units of length cubed (mm^3 or m^3).
I = Area moment of inertia.
Y = Distance from neutral axis to the outermost fiber.
Section modulus is a geometric property for a given cross section used in the design of beams or flexural members. Other geometric properties used in design inculde area for tension and shear, radius of gyration for compression, And second moment of area and second moment of area for stiffness. Any relationship between these properties is highly dependent on the shape in question.
SECTION MODULUS CALCULATION OF THE HOOD DESIGN :
CASE 1: Before optimization
Here the section modulus is calculated by taking the intersection using section inertia analysis. 
MOI (I-max)= 4.786532318*10^6 mm^4
MOI (I-min)= 1.550390972*10^4 mm^4
Y= 876.6169/2
= 438.30845 mm
Z(max)= I-max/Y
= 10920.465 mm^3
Z(min)= I-min/Y
= 35.372144 mm^3
Z1 = 35.372144 mm^3
CASE 2: After optimization
By increasing the depth of inner panel by 0.5mm, the cross sectional area of the hood increases which further increases section modulus.
MOI(I-max)= 4.777515021*10^6 mm^4
MOI(I-min)= 1.569213183*10^4 mm^4
Y= 876.6169/2
=438.30845 mm
Z(max)= I-max/Y
= 10899.8925 mm^3
Z(min)= I-min/Y
= 35.80157 mm^3
Z2= 35.80157 mm^3
CONCLUSION:
After the calculations of the above 2 cases the section modulus Z1 and Z2 are differ by 0.4295 mm.
The section modulus valus of case 2 is higher than the case 1. Thus, Strength of material is directly proportional to the moment of interia and thus increasing the section area also increases the strength of component. Thus section modulus for the hood design is calculated and optimized design is also done to increase the section modulus of the hood.