Section Modulus calculation and optimization

SECTION MODULUS CALCULATION AND OPTIMIZATION

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 the geometric property of a given cross-section used in the design of flexural members. Section modulus depends only on the cross-section shape of the beam or structure.
• For symmetric sections, the value of section modulus is the same for both above and below of centroid of the cross-section. An asymmetric section has two values for the top and bottom of the centroid, the maximum section modulus (S_max) and minimum section modulus (S_min).

FORMULA

S = I/y

S = Section Modulus

I = Moment of Inertia

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

SECTION MODULUS OF THE INITIAL HOOD DESIGN

I_max = 88934616.4 mm⁴

I_min = 274646.854 mm⁴

y = 440 mm

S_max = I_max / y = 88934616.4 / 440 = 202124.128 mm³

S_min = I_min / y = 274646.854 / 440 = 624.197395 mm³

SECTION MODULUS OF THE OPTIMIZED HOOD DESIGN

Here the section area is increased by reducing the embossing depth and offsetting the outer panel by 1 mm. This increases the value of section modulus.

I_max = 89006228.6 mm⁴

I_min = 276422.155 mm⁴

y = 440 mm

S_max = I_max / y = 89006228.6 / 440 = 202286.883 mm³

S_min = I_min / y = 276422.155 / 440 = 628.23217 mm³

CONCLUSION

• By comparing the values of the two cases we can say that section modulus of the optimized hood is increased.
• MOI increases with the increase of section area.
• MOI increases with the increase of section length.