Section Modulus calculation and optimization

                                                                                            SECTION MODULUS CALCULATION AND OPTIMIZATION

 Section Modulus

• It is defined as the ratio of the moment of inertia of a section about its centroidal axis and to distance of extreme layer from neutral axis.
• It give as about an idea about how much of load the given structure can take.
• I f the Section modulus increases the moment of resistance increases and hence its load bearing capacity.

S=I/Y

S= SECTION MODULUS

I = MOMENT OF INERTIA

Y= DISTANCE BETWEEN THE NEUTRAL AXIS TO THE EXTREME END OF OBJECT.

Moment of Inertia

Moment of inertia is defined as the tendency of an object to remain in a state of rest or of a constant rotational velocity. Greater the moment of inertia, more torque is required to change this state. Torque in rotational motion plays the same role as force in linear motion. 

Types of Moment of Inertia

• Mass Moment of Inertia
• Area Moment of Inertia
• Polar Moment of Inertia

SECTION MODULUS CALCULATION

Section Modulus is calculated by two different condition,

• Body at Rest Condition
• Body offset at 0.5mm

Body at Rest Condition

Using Wave Geomentry Linker Select the Hood Inner Panel and Outer Panel to get the intersection line of the part. To calculate the moment of inertia sketch the projected line and trim the inner edges of the part, close the sketch of outer line of the hood inner and outer panel.

                       

Using Section Inertia Analaysis we got maximum inertia and minimum inertia 

MOI(MAX)=8.097579199e^05 mm^4

MOI(MIN)=3.559786253e^03mm^4

Distance between neutral axis to end of object

Distance between Neutral Axis to End of object(Y)=482.9220mm/2= 241.461mm

Section Modulus at Max Moment of inertia

S=I/Y

S=8.097579199e^05 mm^4/241.461mm

=3.3535764e^03 mm^3

Section Modulus at minimum moment of inertia

S= 3.559786253e^03mm^4/241.461mm

=14.7426963 mm^3

We can take the section modulus value for the minimum moment of Inertia.

S= 14.7426963 mm^3

• Body Offset at 0.5mm

           

S=I/Y

MOI(MAX)=8.024083907e^05 mm^4

MOI(MIN)=3.289621966e^03 mm^4

Distance between neutral axis to end of object

Distance between neutral axis to end of object(Y)= 481.9399/2 = 240.96995mm.

Section modulus at maximum moment of inertia

S=8.024083907e^05 mm^4/240.96995mm

=3.329910e^03 mm^3

Section Modulus at minimum moment of inertia

S=3.289621966e^03 mm^4/240.96995 mm

=13.6515858 mm^3

We can take the Section Modulus of minimum moment of Inertia is 13.6515858 mm^3.

CONCLUSION

Body Condition	Rest Condition	0.5mm Offset
Section Modulus of Min.Moment of Inertia value	14.7426963 mm^3	13.6515858 mm^3