Section Modulus calculation and optimization
SECTION MODULUS CALCULATION AND OPTIMIZATION
- AIM-use the section from hood design and calculate the section modulus using the formula
- S=I/Y ,
S=section modulus,I=moment of inertia
Y=Distance between the neutral axis and the extreme end of the object.
- SECTION MODULUS-it is the ratio of moment of inertia (I) of the beam cross -section about the neutral axis to the distance (Ymax) of extreme fibre from the neutral axis ,Z=I/Ymax.
- MOMENT OF INERTIA-
It is a measure of an objects resistance to changes to its rotation.
- Also defined as the capacity of a cross-section to resist bending.
- it must be specified with respect to a chosen axis of rotation.
- NEUTRAL AXIS-The neutral axis is a line or plane through a beam or plate connecting points at which no extension or compression occurs when it is bent.
- CALCULATING THE SECTION MODULUS FROM THE HOOD DESIGN-
- create a xy plane so that hood design must part into two half and the force must be perpendicular to the plane
- FIND The intersection curve between the created datum plane and the hood.
- The section is to be made a closed section to calculated the SECTION INERTIA .first be project the intersection curve on the plane and then connect the whole curve ,so that it become a close loop .we can get actual MOI & section modulus.
- Take a point at both the extreme side of the hood, measure the distance between the points half of the distance will be 'Y'.since we are taking the 'O-Y' axis as a neutral axis.
- Using the inertia analysis command calculate the moment of inertia of the section.
CALCULATION OF SECTION MODULUS-
MOI(I)=2.631388303*10^5MM^4
Ymax-876.492/2=438.246mm
section modulus(z)=I/Ymax=2.631388303*10^5/438.246=600.34775mm^3
MODIFICATION TO INCREASE SECTION MODULUS & MOI-
for approaching in this way i decrease the embosses with respect to the outer surface of inner hood plane.this leads to increase the moi about the neutral axis which proportionally increase the z
CALCULATION OF SECTION MODULUS-
MOI-2.67822672*10^5MM^4
YMAX-867.492/2=432.2mm
SECTION MODULUS-I/Ymax=2.67822672*10^5/432.2=617.769mm^3
CONCLUSION-Hence after modification section modulus increase as compare to 1st MOI thus increase bending strength of the hood.