Section Modulus calculation and optimization

SECTION MODULUS

Objective:

To calculate the section modulus for the previously designed hood and optimized hood.

To come up with the new section that has improved section modulus of the previous section.

Section Modulus:

Section Modulus is a geomentry for a given cross section used in the design of beams or flexural members. Also section modulus is a direct measure of strength of flexural members. Higher section modulus will be resistance for bending. Section modulus is a ratio of moment of inertia to the distance from the neutral axis to the point where the bending normal stress is determined.

Secction Modulus is given by the formula:

S = I/Y

Where,

S = Sectional Modulus.

I = Moment of Inertia.

Y = Distance between the neutral axis and the extreme end of the object.

Design 1:

From the following above analysis, Maximum and Minimum Moment of Inertia are obtained.

Imax = 4761.945 mm, Imin = 13.242 mm, Y = 437.915 mm

Smax = 4761.945/437.915 = 10.87 mm

Smin = 13.242/437.95 = 0.0302 mm

Design 2:

Outer panel with 0.2 mm offset towards inner panel with no geometry changes. If we increase the offset value more than 0.2 mm, both inner and outer panel merge together.

From the following above analysis, Maximum and Minimum Moment of Inertia are obtained.

Imax = 4741.946 mm, Imin = 13.096 mm, Y = 437.95 mm

Smax = 4741.976/437.95 = 10.82 mm

Smin = 13.096/437.95 = 0.0299 mm

Conclusion:

By compare the value We can say that section modulus of the optimizedd hood of design 2 increased by 0.05%.

From the formula We can say that the section modulus is directly proportional to its Moment Inertia.

Moment of Inertia is given as the "Sum of the product of mass" of each particle with the "Square of its distance from the axis of the rotation".

Thus to increase the Moment of Inertia we have to increase the gap between outer and inner panel.