Section Modulus calculation and optimization

SECTION MODULUS

Section modulus is the property of the cross-section that is used while the design of beams.

It is the direct measure of the strength of the shaft section or the beam section.

The section modulus is classified into two types:-

1] Elastic section modulus:- The elastic section modulus is applicable up to the yield point of material.It is used in most engineering applications.

2] Plastic section modulus:- The plastic section modulus is generally used for material in which plastic behavior is observed.

ELASTIC SECTION MODULUS

Elastic section modulus is the ratio of moment of inertia about a neutral axis and the maximum distance between the neutral axis and outermost edge of object.

Elastic section modulus equation:-

The formula of elastic section modulus is given by,

S=I/Y

Where,
I = Moment of inertia (m4m4)
Y = Distance between neutral axes and outermost edge of object (m)

PLASTIC SECTION MODULUS

The plastic section modulus is the addition of moment of area of area under compression about plastic neutral axis and the moment of area of area under tensile stress.

SECTION MODULUS OF MY DESIGN

Moment of inertia (max), I max =3.94305*10^6 mm^4

Moment of inertia (min), I min =1.079931*10^4 mm^4

Distance between neutral axes and outermost edge of object,Y=815.07/2=407.535 mm

Section modulus,Smax=I max/Y=3.94305*10^6/407.535=9675.36 mm^3

Section modulus,Smin=I min/Y=1.079931*10^4/407.535=26.49 mm^3

When the depth of my design increased by increasing the depth of emboss,

Moment of inertia (max), I max =3.94434*10^6 mm^4

Moment of inertia (min), I min =1.15645*10^4 mm^4

Distance between neutral axes and outermost edge of object,Y=815.07/2=407.535 mm

Section modulus,Smax=I max/Y=3.94434*10^6 /407.535=9678.53 mm^3

Section modulus,Smin=I min/Y=1.15645*10^4/407.535=28.37 mm^3

So the increase in depth produces increase in section modulus and thus strength.