Section Modulus calculation and optimization

AIM: To calculate the section modulus of the hood panel and then optimizing the hood panel for better section modulus.

section modulus:

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 the design include an area for tension and shear, the radius of gyration for compression, and moment of inertia and polar moment of inertia for stiffness. Any relationship between these properties is highly dependent on the shape in question.

It is termed as the ratio of the second moment of inertia and distance from N.A (Neutral axis) to the extreme fiber. Also, it is the measure of the strength of a given member. The stress in the outermost section of the beam is computed with the help of section modulus. It is indicated by S.

Section modulus is indicated as follows:

S = Section Modulus

I = Moment of Inertia

y = distance between the neutral axis and the extreme end of the object

First analyse the base section

where ,

max MOI = 8.248427271e + 005 [mm*4]

min MOI = 3.175481768e + 003 [mm*4]

H = 491.2 , y = H/2 : y= 245.6

section modulus S = I/y

FOR first analysis of max MOI S = Imax/y

= 824842.7271/245.6

= 3358.480159 mm*3

for first analysis of min MOI S = Imin/y

= 3175.481768/245.6

=12.929mm*3

AFTER DESIGN MODIFICATION (by inwardly offsetting the inner hood curve at a distance of 0.5 mm )

max MOI = 8.314203544e + 005 [mm*4]

min MOI = 3.040756209e + 003 [mm*4]

max MOI S = Imax/y

=831420.3544/245.6

=3385.2620 mm*3

min MOI S = Imin/y

= 3040.756209/245.6

= 12.380 mm*3

after design modification section modulus has been increased this indicates the strength of the hood has been increased.