Section Modulus calculation and optimization
OBJECTIVE:
To use the section from a hood design and calculate the section modulus and make change to increase strength.
INTRODUCTION:
Section modulus is a direct measure of strength of any sectional area of an object about an reference axis(neutral axis). Strength is nothing but, capable of supporting greater loads, so higher the strength it has a high capable of supporting greater loads. This strength can measured directly from Section modulus formula, and defined by below formula. Section modulus represented with a symbol of 'S:
S=I/Y
where 'I'moment of inertia
'Y' is the distance from the reference line(neutral axis) to one of the extreme end of an object.
Moment of inertia is nothing but offering resistance against of moment, bending or twisting, i.e if we applied any external load on the body, how much resistance its offering to tend to deform. So, higher the value of moment of inertia, have higher resistance to deform under certain load, hence we can say that moment of inertia directly proportional to the strength of the material, and strength of the material can be calculated with the help of section modulus.
If we vary the neutral axis towards positive or negative side the overall strength of the body will decrease, because when neutral axis line lies on the middle of the section only have higher strength at particular point. so, here 'Y' value was inversely proportional to section modulus.
Thats why formula represented as above.
By using the same principle i going to calculate the strength of an hood panel.
CASE 1:
maximum moment of inertia=4.829628305e+06[mm^4]
minimum moment of inertia=1.491023519e+04[mm^4]
The total distance of hood Y =874.71mm
Distance between the neutral axis to the extreme end=(874.71/2)=437.355mm
To find section modulus of hood section, we have to calculate
S=I/Y=4.829628/437.355=0.01104mm^3
This is the maximum strength of the hood design.
CASE 2:
By modifying the design of the hood with increse the thickness between outer and inner panel now we going to determine the section modules will increase or not by following same formula.
Maximum moment inertia=7.291635e+06[mm^4]
Minimum moment inertia=2.267610e+04[mm^4]
The total distance of hood Y=874.71mm
Distance between the neutral axis to the extreme end=(874.71/2)=437.355mm
To find section modulus of hood section, we have to calculate
S=I/Y
=7.291636/437.355
=0.01667mm^3
This is the maximum strength of the hood design.
when we compare both of the case 1 and 2. we get more strength in the case 2 because of increasing thickness of the hood.
CONCLUSION:
Thus we calculated the section modulus for a hood design, hence increase in section area there is have increase in overall mass of an object, hence have increase in strength.