Section Modulus calculation and optimization

Aim :To calculate Section Modulus and to increase the same by modifying Front Hood Section.

Formula to be used as below.

Formula: S = I / Y

S = Section Modulus

I = Moment of Inertia - Calculate using NX Cad

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

Brief Introduction Section Modulus :

• Section Modulus is the total moment resisted by the section to the stress in the extreme fibre. It gives an idea about how much load the structure can take. A high setion modulus means better load - bearing capacity.
• For General design, the elastic section modulus is used to applying yield point for the most metals and the other common materials. The elastic section modulus is definied as S= I/Y.
• Moment of Inertia : Moment of inertia can be defined with respect to rotation axis, as aquality that decides the amount torque required for a designed angular accelaration or a property of a body due to which it resist angular acceleration. The formula for moment of inertia is the ' Sum of the product of mass ' of each particlewith the ' Square of its distance from the axis of the rotation'. I = ∑m_i r_i²

Calculation :

To be calculated as Hollow section and Thickness will be 0.75

1. Section Modulus for basic or unmodified section of Front Roof :

• Section Inertia Analysis Data for section 1 -

• Y = distance between the neutral axis and the extreme end of the object

As we can see here, MOI(min) ( I ) = 1.15213065e+05[mm^4] = 1,15,000 [mm^4]

( Y ) = 486.0528 mm

S = I / Y

= 1,15,000 [mm^4] / 486.0528[mm]

= 236.599 [mm^3]

2. Section Modulus for modified section of Front Roof :

• Reason of modification -

• Modify to increase Moment of Inertia of perticular section.
• Moment of Inertia is directly proposional to Section Modulus. In the resultant of modification Section Modulus will also increase.
• If Section modulus will icrease than we can say we are directly increasing regidity or strength of perticular section.

• Section Inertia Analysis Data for section 2 - A modified section -

• By adding two more embosses as we can see in the above pic, I have increased area of that perticular section.
• By increasing area of the section i have increased Moment of Inertia of the section.
• As we discussed by increasing MOI, We can get improvement in Section Moudulus and accordingly strength will be increase.

• Y = distance between the neutral axis and the extreme end of the object

As we can see here, MOI(min) ( I ) = 2.602873835e+05[mm^4] = 2,60,000 [mm^4]

( Y ) = 486.0528 [mm]

S = I / Y

= 2,60,000 [mm^4] / 486.0528 [mm]

= 534.921 [mm^3]

Conclusion :

• By using NX Cad software i have modified Front Hood section area to improve Section Modulus.
• We have increased Momnet of Inertia and Section Modulus by increasing the area and modified the given section.
• As per the result we can say that by increasing area of perticular section we can increase Moment of Inertia for the same and By increasing MOI we can improve or increase Section Modulus. At the end by this modification we have increased strength and Rigidity of this section.