SECTION MODULUS CALCULATION OF HOOD

Aim :

To calculate section modulus in hood by using of NX CAD Software

Section modulus :

Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members. Other geometric properties used in design include area for tension and shear, radius of gyration for compression, and moment of inertia and polar moment of inertia for stiffness. Any relationship between these properties is highly dependent on the shape in question. Equations for the section moduli of common shapes are given below. There are two types of section moduli, the elastic section modulus and the plastic section modulus.

Notation :

North American and British/Australian convention reverse the usage of S & Z. Elastic modulus is S in North America but Z in Britain/Australia, and vice versa for the plastic modulus.

Elastic section modulus :

For general design, the elastic section modulus is used, applying up to the yield point for most metals and other common materials.

S = I / y

The elastic section modulus is defined as S = I / y, where I is the moment of inertia and y is the distance from the neutral axis to any given fibre

Plastic section modulus :

The plastic section modulus is the sum of the areas of the cross section on each side of the PNA (which may or may not be equal) multiplied by the distance from the local centroids of the two areas to the PNA:

The Plastic Section Modulus can also be called the 'First moment of area'

Section modulus model 1 :

Calculation :

S = I / y

I - moment of inertia

I = 4.78544342 × 10⁶ mm⁴

y - distance from the neutral axis to left or right most end

y = 439.9749 mm

S = 4.78544342 × 10⁶mm^{4 /} 439.9749 mm

S =10876.6282 mm³

Section modulus model 2 :

Calculation :

S = I / y

I - moment of inertia

I = 4.8183257 × 10⁶ mm⁴

y - distance from the neutral axis to left or right most end

y = 439.9749 mm

S =4.8183257 × 10⁶mm^{4 /} 439.9749 mm

S =10951.3649 mm³

Comparison chart :

Conclusion :

1. I have explained the defenition of section modulus ,writtten formula, and also explain elastic and plastic section modulus .

2. I calculated section modulus of hood in two different thicness . Resul of this analysis by comparision of final value thickness of outer panel incress MOI (moment of inertia) and section modulus value also increase.

3. The larger section modulus mean more stiffness and greater supporting load