Section Modulus calculation and optimization

OBJECTIVE:

To calculate the section modulus of the hood created and modify its structure to increase the section modulus in NX CAD software.

SECTION MODULUS:

Section modulus is a geometric property of the cross section used for designing beams and flexural members. Section modulus may be defined as the ratio of total moment resisted by the section to the stress in the extreme fibre which is equal to yield stress. The formula for section modulus is given by

S = I / y

Where,

S = section modulus

I = moment of inertia

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

CALCULATION:

1.NORMAL SECTION:

A neutral plane is created on the middle of the hood and outline of the hood is taken for analysis. The open outline is closed before analysis. The moment of inertia, section area and distance from neutral axis to end object are found in the software for the section modulus calculation.

From the analysis,

MOI_min = 1.490183 x 10⁰⁴mm⁴

Section Area = 73.2205mm²

Distance, y = 440.3743mm

So, S = 1.490183 x 10⁰⁴ / 440.3743 = 0.03383x10³mm³

2.MODIFIED SECTION:

To increase the stiffness of the hood section, the structure is slightly modified and section modulus is calculated for that section using the above method.

From the above analysis,

MOI_min = 1.64366 x 10⁰⁴mm⁴

Section Area = 74.88128mm²

Distance, y = 440.3743mm

So, S = 1.64366x10⁴ / 440.3743 = 0.03732x10³mm³

INFERENCE:

So, from the above calculations for two different sections, we can say that by increasing the section area, both moment of inertia and section modulus are increasing. This shows that modified section is better than normal section such that modified section can withstand more load.

CONCLUSION:

Thus the section modulus is calculated for the hood and also created a modified section of the hood which has higher moment of inertia, section area and section modulus.