Section Modulus calculation and optimization

SECTION MODULUS CALCULATION OF HOOD

Aim

• To calculate the section modulus of the previously designed hood for analyzing its strength and also optimizing the design to see the difference in the bending strength of the hood. Higher the section modulus of a structure, the more the resistive it becomes to bending.

Section modulus

• Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members, it is also referred to as the Polar Modulus or the Torsional Sectional Modulus.
• Other geometric properties used in design include area for tension and shear, 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. Equations for the section moduli of common shapes are given below.
• There are two types of section moduli, the elastic section modulus and the plastic section modulus.

S=I/Y

Here,

S = Section modulus

I= Moment of Inertia (Unit mm 4)

Y= Distance from Neutral axis to the extreme end (unit mm)

The Unit of a “section modulus” is (mm3)

First Design Study

• The Intersection of the design was taken and then section Inertia Analysis was done

Moment of inertia(max) = 8.721×10^5×mm^4

Moment of inertia(min) =1.599×10^3×mm^4

Y=487.284/2=243.642mm

S=I/Y

1) Section Modulus = 8.721×10^5×mm^4/243.642mm

= 3.721×10^3mm³(Maximum strength).

Now, one more trail is that, here the inner panel curve offsetting outside by 0.5 mmi.e increasing in cross sectional area,the results shown below.

Here,

Moment of inertia(max) = 8.309×10^5×mm^4

Moment of inertia(min) = 1.551×10^3×mm^4

2) Y=487.284/2=243.642 mm

S=I/Y

S=8.309×10^5×mm^4/243.642 mm

=3.410×10^5×mm

Conclusion

So, here the difference can be seen in the moment of inertia and the change in the section modulus can be seen by the change in the design(depth).