Section Modulus calculation and optimization
Aim:
To find the section modulus of the hood and optimization to improve the overall section modulus.
Objective:
Use the section from your Hood design and calculate the section modulus using the formula S= I/y.
Section Modulus:
The section modulus (S) is geometry property of the cross section used for designing beams and flexural members. It does not represent anything physically.
TWO TYPES OF SECTION MODULUS
1. ELASTIC SECTION MODULUS:
IT IS USED FOR THE MATERIALS WHICH BEHAVE ELASTICALLY UNDER THE LOADING
2.PLASTIC SECTION MODULUS:
IT IS USED FOR MATERIALS WHICH HAVE PLASTIC BEHAVIOUR.
IN ENGINEERING WE ALWAYS HAVE TO CALCULATE THE ELASTIC SECTION MODULUS. AS WE ASSUME ALL MATERIALS TO BE OF ELASTIC BEHAVIOUR
Formula of section Modulus:
It 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.
Which is equal to yield stress.
Therefore
S=I/y, Where
S= Section modulus (mm^3)
I = Moment of inertia of the section to the stress in the extreme end of the object (mm^4)
Y= Distance between the neutral axis and extreme end of the object (mm).
Area Moment of Inertia:
The area moment of inertia of a beam cross section area measures the beam ability to resist bending. The larger the moment of inertia less will be the bend.
Case: 1
Here,
Moment of inertia(max) = 4.812349620×10^6×mm^4
Moment of inertia(min) = 1.575450663×10^4×mm^4
VALUE OF Y IS 877.7555/2 =438.87775
Z min= 1.575450663x10^4/438.87775
=35.897255mm^4
S = 35.897255mm^4
Case: 2
Here,
Moment of inertia(max) = 4.785638866×10^6×mm^4
Moment of inertia(min) = 1.656587694×10^4×mm^4
VALUE OF Y IS 877.7555/2 =438.87775
Z min= 1.656587694x10^4/438.87775
=37.745994 mm^4
S = 37.745994 mm^4
comparing case 1 and 2:
The section modulus value of case 2 is higher than the case 1.
Conclusion:
As we increase the section area , the moment of Inertia & section modulus increases which means the strength and load capacity of material also increases.