Section Modulus calculation and optimization

OBJECTIVE:

To increase the section modulus of the hood for increasing strength by using Nx cad.

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 of tension and shear, radius for gyration for compression and moment of inertia and polar moment of inertia for stiffness.

It is termed as the ratio of the second moment of area and distance from the neutral axis to the extreme fiber. and also it is the measure of strength of the given member. The stress in the outer most section in the beam is computed with the help of section modulus. The section modulus is indicated as S.

S=I/Y

Here,

I= Moment of inertia

Y= distance from the neutral axis to end

Section modulus depends only on the cross-section shape of the structure. for symmetric sections the value of the section modulus is for both above and below of centroid of the fiber. An asymmetric sections has two values for top and also the bottom of the fiber due to the different distance from the top and bottom of the material, and The maxium section modulus is Smax and minimum section modulus is Smin.

NOTE:

1)It is a significant for beam and flexural member design.

2)More the section modulus, will be The more member is resistant to the bending of the beam.

3)It is easier to calculate stress on the beam and an exact measure of the strength of the steel

4)If two beams are made of the same material and comparing the section modulus of the two beams, the beam with bigger modulus will be have more strength and more capable to with stand larger loads.

Section modulus calculation of the hood design.

Case 1 : Initial Hood Design.

MOI(min): 2.721537298e+05(mm^4)

y distance:

Y=439.367mm

S=I/Y

S=2.721537298e+05(mm^4)/439.4mm

S=620.105mm^3

CASE 2:Improved hood design

MOI (min):2.932456713e+05(mm^4)

changes made: I increased the crossectional area up to .5mm (increased)

y distance:

Y= 439.4mm

S=I/Y

S=2.932456713e+05(mm^4)/439.4

4mm

s=667.377mm^3

FINAL RESULT: Thus the stiffness of car hood has been increased by increasing the inertia.

Conclusion:

1.By comparing values we can clearly say that the section modulus of the improved hood has increased.

2.moment of inertia increased by increasing depth of hood.

3.seems if we increase the gap between inner and outer panel also increases.