Section Modulus calculation and optimization

QUESTION:--

Use the Section from your Hood design and calculate the Section Modulus using the formula 

`S = I/y`

 Where, 

S = Section Modulus

I = Moment of Inertia

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

Come up with a new section that has an improved Section Modulus compared to the previous one and mention what changes you made which resulted in the increased strength.

ANSWER:--

WHAT IS SECTION  MODULUS ?

• Ratio of total moment resisted by the section to the stress in the extreme fibre.
• It gives us an idea about how much of load the given structure can take.
• If the section modulus Increases the moment of resistance Increasesand hence its load bearing capacity.
• It gives an idea that most of the work in bending is being done by the extreme fibres of the beam, ie the top and bottom fibres of the section.

HOW TO CALCULATE SECTION MODULUS:--

• So here in this Challange we we will be taking the section of our designed hood for our calculations 
• We will take the section along the length of the hood and find the moment of inertia using "Intertia Analysis tool" in NX
• Then the value can be used to find modulus using the formula given 

           `S=I/y`

Where,

S = Section Modulus

I = Moment of Inertia

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

In this case we will take it from the center to the outer edge of the hemming outer pannel

                                                        Fig:Section Modulus of Hood

Now Lets Calculate Section Modulus of the hood By keeping Moment of inertia into an account

                                                   Fig:Moment of Inertia of the hood 

                                                   

           `S=I/y`

Where,

S = Section Modulus 

`I = I(min)=1.5690*10^3 mm^4`

`y = 440.6 mm`

In this case we will take it from the center to the outer edge of the hemming outer pannel

`S=3.5610 mm^3`

Similarly, We have to optimize the section modulus, by extending the lower most edge of inner panel & then calculated the moment of inertia for each extension of inner panel's edge:

`S=I/y`

Where,

S = Section Modulus 

`I = I(min)=1.6033*10^3 mm^4`

`y = 440.6 mm`

In this case we will take it from the center to the outer edge of the hemming outer pannel

`S=3.6389mm^3`

`S=I/y`

S = Section Modulus 

`I = I(min)=1.5934*10^3 mm^4`

`y = 440.6 mm`

In this case we will take it from the center to the outer edge of the hemming outer pannel

`S=3.6164mm^3`

`S=I/y`

S = Section Modulus 

`I = I(min)=1.4672*10^3 mm^4`

`y = 440.6 mm`

In this case we will take it from the center to the outer edge of the hemming outer pannel

`S=3.3300mm^3`

 As 'Moment of inertia' is directly proportional to the 'section modulus', thus the value of section modulus is increasing with the value of moment of inertia.

What changes you made which resulted in the increased strength.

I changed the inner pannel embosess so that the Load Bearing Capacity Increases and Moment of inertia increases and Section Modulus is also increased 

CONCLUSION:--

•  The section modulus of my hood section is 3.5610 mm^3 .
•  And after extending the lower most edge of the inner panel & calculating the section modulus, we found that with the extent of lower most edge of inner panel we can increased the load bearing capacity
• Thus, the largest section modulus of hood section is 3.6389mm^3
• From This i learend how to calculate section modulus of the model and how we can increase the load bearing capacity.