Section Modulus calculation and optimization

Aim:

To calculate and compare the section modulous of the Car front Hood

Intoduction:

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. The section moduli of different profiles can also be found as numerical values for common profiles in tables listing properties of such. Section modulus is the direct measure of the strength of the steel. Bending a steel section that has a larger section modulus than another will be stronger and harder to bend. Section modulus is a geometric property for a given cross-section used in the design of flexural members

There are two types of section modulus,

1. The elastic section modulus
2. The plastic section modulus

Section Modulus can be calculated by using the Formula :

S = I / y

Where,

S = Section Modulus

I = Moment of inertia

Y = Distance from the neutral axis to the most extreme end of the object

Distance from the neutral axis to the most extreme end of the object :

Y =895.273 / 2

Y = 447.6365 mm

Section Modulous Analysis:

Case 1

Section intertia of the designed Car hood model:

• Take the intersection of the Hood design horizontally as shown in the below image

• Measure the Inertia using Measure Inertia command

Apply the values in the formula, Section Modulus (S)

S = I / y

where,

I = 2.41 x 10-6 m4

y = 447.6365 mm

S = 2.41 x 10-6 m4 / 447.6365mm

= 5383.83 mm3

Case 2

Increase the Area of cross section of the hood by increasing the gap between the inner and the outer panel by 0.5mm

• Measure the Inertia using Measure Inertia command

Apply the values in the formula, Section Modulus (S)

S = I / y

where,

I = 2.514x 10-6 m4

y = 447.6365 mm

S = 2.514 x 10-6 m4 / 447.6365mm

= 5616.164 mm3

When we compare case 1 and case 2, the section modulus is found to be more in case 2 this because the gap between the inner panel and the outer panel was increased. Therefore, the moment of inertia is directly proportional to the area of cross section.

Result:

Thus, the comparison is section modulus was found for the designed car hood.