Section Modulus calculation and optimization

SECTION MODULUS CALCULATION AND OPTIMIZATION

AIM

The aim of the challenge is to calculate the section modulus value for the hood we designed and try to improve it.

THEORY

Section Modulus:

Section Modulus is also known as Polar modulus. It is a geometric property for a given cross-section used in the design of beams or flexural members. It is the direct measure of the strength of the shaft section or the beam section. Higher the section modulus of a structure, the more resistive it becomes to bending. Other geometric properties used in the design include an area for tension and shear, the radius of gyration for compression, and the moment of inertia, and the polar moment of inertia for stiffness. Any relationship between these properties is highly dependent on the shape.

There are two types of section modulus,

1. The elastic section modulus.
2. The plastic section modulus.

CALCULATION AND OPTIMIZATION

A 'section modulus is the value of the "moment of inertia of area related to the neutral axis of the cross-section of a beam multiplied by the distance from the neutral axis to the outer surface'.

Therefore, the relationship between the section modulus Z and the moment of inertia of area l is expressed by the following equation.

Z=I/Y (mm^3 or m^3)

(I is the moment of inertia of area and Y is the distance from the neutral axis to the extreme end of the object).

Now, we see the section modulus of the sections with regard to the Frontal crash.

Y=880.0mm/2=440mm.

EXISTING SECTION

We take the minimum moment of inertia, I= 2.783954621*10^5(mm^4).

Section modulus S=2.783954621*10^5/440=632.717mm^3.

Now there are two ways we can improve the section modulus by increasing the area of the section.

1. By creating embossed surfaces.
2. Completely offsetting the outer boundary of the inner panel.

Now I will show only by completely offsetting the outer boundary of the inner panel.

We take the minimum moment of inertia, I=3.013015662*10^5mm^4.

Section modulus S=3.013015662*10^5/440=684.776mm^3.

From the calculated values we can see that the section modulus is improved in the above case similarly we can do this by creating emboss surface but depending upon how we would want to increase the area we can choose between these two methods.

CONCLUSION

Section modulus for the designed hood assembly is calculated and improved.