Section Modulus calculation and optimization

SECTION MODULUS OF HOOD DESIGN

AIM:

To calculate the section modulus for my previous hood design and optimization of hood

SECTION MODULUS:

Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members.

Section modulus represented with a symbol of 'S'.

S= I/Y

Where 'I' moment of inertia

'Y' is the distance from the reference line (neutral axis) to one of the extreme end of an object.

Moment of inertia, in physics, quantitative measure of the rotational inertia of a body i.e., the opposition that the body exhibits to having its speed of rotation about an axis altered by the application of a torque (turning force). The axis may be internal or external and may or may not be fixed.

Moment of inertia directly proportional to the strength of the material, and strength of the material can be calculated with the help of section modulus.

When neutral axis line lies on the middle of the section only have higher strength at particular point, so, here 'Y' value was inversely proportional to section modulus. By using the principle i going to calculate the strength of a hood panel,

Here the moment of inertia was calculated by using the NX-software obtained values are

I max= 5.84427X10^{^6}mm^4

I min = 2.96357x10^{^4}mm^4

Total length of 'Y' value was 460.2mm

So, at neutral axis we need 'Y' value:-Y/2=460.2/2=230.1mm

• Section modulus(S):-I/Y=5.84427X10^{^6}mm^4/230.1mm

S max = 25.398x10^3 mm^3

• Section modulus(S):-I/Y= 2.96357x10^{^4}mm^4/230.1

S min = 0.128x10^3 mm^3

So that strength is varies from 0.128x10^3 mm^3 to 25.398x10^3 mm^3

Hood Optimization is done by decreasing the 1mm for from inner panel and hood hinge emboss,

Here the moment of inertia was calculated by using the NX-software obtained values are

I max= 5.78658X10^{^6}mm^4

I min = 2.64705x10^{^4}mm^4

Total length of 'Y' value was 460.2mm

So, at neutral axis we need 'Y' value:-Y/2=460.2/2=230.1mm

• Section modulus(S):-I/Y= 5.78658X10^{^6}mm^4/230.1mm

S max = 25.148x10^3 mm^3

• Section modulus(S):-I/Y== 2.64705x10^{^4}mm^4/230.1

S min = 0.115x10^3 mm^3

So that strength is varies from 0.115x10^3 mm^3 to 25.148x10^3 mm^3

When comparing both the hoods there is change in both MAX and MIN strength values,

Here I decreased the sectional area by 1mm

Minimum strength decreased from 0.128x10^3 mm^3 to 0.115x10^3 mm^3

Maximum strength decreased from 25.398x10^3 mm^3 to 25.148x10^3 mm^3.

From the result get from the above trail,

When decrease in cross sectional area there will be decrease strength and vice versa.

And moreover the strength mainly depends upon the selection of material and thickness and cross sectional area of an object.

CONCLUSION:

The strength of the material is directly proportional to the moment of inertia. Hence hood optimization is done with different sectional area and got the respective results.