Section Modulus calculation and optimization

AIM:

To calculate the section modulus of the hood panel and then optimise the hood panel for a better section modulus.

INTRODUCTION:

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 the design include an area for tension and shear, the radius of gyration for compression, and the moment of inertia and polar moment of inertia for stiffness.
• Any relationship between these properties is highly dependent on the shape in question.
• It is termed the ratio of the second moment of inertia and distance from N. A (Neutral axis) to the extreme fibre. Also, it is the measure of the strength of a given member. The stress in the outermost section of the beam is computed with the help of section modulus. It is indicated by S.

MOMENT OF INERTIA:

• The moment of inertia of an object is a determined measurement for a rigid body rotating around a fixed axis.
• The axis might be internal or external, and it can be fixed or not. However, the moment of inertia (I) is always described in relation to that axis.
• The moment of Inertia depends on the distribution of the mass around its axis of rotation. MOI varies depending upon the position of the axis that is chosen. That is, depending on the location and direction of the axis of rotation, the same item might have a various moment of inertia values.

CASE 1:

SECTION MODULUS CALCULATION:

S=l/y

S = Section Modulus

I = Moment of Inertia

y = distance between the neutral axis and the extreme end of the object.

SECTION MODULUS CALCULATION OF HOOD ASSEMBLY DESIGN:

Moment of Inertia M1=1.525x10^-6 m^4 (Min)

we have changed m^4 to mm^4

1m^4=10^12 mm^4

So Moment of inertia ,I= 1.525x 10^6 mm^4

y= Total length /2

y=478.032/2

y= 239.016 mm.

Section modulus = I/y

= 1.525x 10^6 / 236.016

Section modulus=6380.0326 mm^3 (MINIMUM).

CASE 2:

OPTIMIZED SECTION MODULUS CALCULATION OF HOOD ASSEMBLY DESIGN:

CALCULATION

Moment of Inertia M1=1.592x10^-6 m^4 (Min)

we have changed m^4 to mm^4

1m^4=10^12 mm^4

So Moment of inertia ,I= 1.592x 10^6 mm^4

y= Total length /2.

y=478.032/2

y= 239.016 mm

Section modulus = I/y

= 1.592x 10^6 / 236.016

Section modulus=6660.642 mm^3 (MINIMUM).

RESULT:

• I have increased the distance between the outer panel and the inner panel by 0.5mm compared to the previous section. So the section modulus strength has to be increased.

• In this study, we take the minimum of inertia moment to analyze the minimum limit of hood deformation. Thus the section modulus of the front hood was calculated and compared with the new design.

• From the result we found out that increasing the cross-section area would give a better section modulus and helps in increasing the strength of the hood.