Section Modulus calculation and optimization

SECTION MODULUS CALCULATION AND OPTIMIZATION:

AIM:

To calculated section modulus of hood design and optimization to improve the overall section modulus.

OBJECTIVES:

Use the Section from your Hood design and calculate the Section Modulus.

SECTION MODULUS:

Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members, it is also referred to as the Polar Modulus or the Torsional Sectional Modulus. 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.

SECTION MODULUS FORMULA:

S = I/y

Where,

S = Section Modulus

I = Moment of Inertia

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

MOMENT OF INERTIA:

Moment of inertia also known as the angular mass or rotational inertia can be defined w.r.t. rotation axis, as a quantity that decides the amount of torque required for a desired angular acceleration or a property of a body due to which it resists angular acceleration.

NEUTRAL AXIS:

The neutral axis is an axis in the cross section of a beam (a member resisting bending) or shaft along which there are no longitudinal stresses or strains.

BEFORE OPTIMIZATION:

The hood which was already created is imported and the section inertia analysis is done. We have to make sure that the curve obtained is a single/closed curve.

MOMENT OF INERTIA (IMAX) =7.83747*10^5 mm^4

MOMENT OF INERTIA (IMIN)=6.6847*10^3 mm^4

TOTAL DISTANCE OF AXIS=478mm

DISTANCE BETWEEN THE NEUTRAL AXIS AND THE EXTREME END OF THE OBJECT (Y)=239mm

SECTION MODULUS=I(MIN)/Y

=6.6847*10^3/239

S = 27.96mm^4

AFTER OPTIMIZATION:

The hood inner panel’s curve is offset by 0.5mm outwards and section inertia analysis is done same as case 1 for a closed curve.

MOMENT OF INERTIA (IMAX)=7.83747*10^5 mm^4

MOMENT OF INERTIA (IMIN)=6.68475*10^3 mm^4

TOTAL DISTANCE OF AXIS=478mm

DISTANCE BETWEEN THE NEUTRAL AXIS AND THE EXTREME END OF THE OBJECT (Y)=239mm

SECTION MODULUS=I(MIN)/Y

=6.68475*10^3/239

S=28.703 mm^4