Section Modulus calculation and optimization

SECTION MODULUS CALCULATION & OPTIMIZATION

- MAYANK TIWARI

AIM - THE MAIN OBJECTIVE IS TO CALCULATE SECTION MODULUS OF HOOD & OPTIMIZE THE DESIGN TO HAVE IMPROVED SECTION MODULUS.

SOFTWARE USED - SEIMENS NX

SECTION-MODULUS - IT IS THE RATIO OF AREA MOMENT OF INERTIA ABOUT THE NEUTRAL AXIS AND TO THE DISTANCE OF OUTERMOST FIBER FROM THE NEUTRAL AXIS.

Z = I/Y

where,

Z= Section Modulus(mm^3), I=Area Moment of Inertia(mm^4)

Y=Distance From Neutral Axis To The Outermost Fiber(mm)

MOMENT OF INERTIA IS NOTHING BUT OFFERING RESISTANCE AGAINST THE MOMENT,BENDING OR TWISTING.SO HIGHER THE MOMENT OF INERTIA, HIGHER WILL BE ITS RESISTANCE TO DEFORM.

CALCULATION IN NX - 1. FIRST WE CREATE DATUM PLANE AT THE MIDDLE OF HOOD PERPENDICULAR TO THE AREA WHERE FRONTAL IMPACT WILL TAKE PLACE.

2. THEN WE TAKE CROSS SECTION OF THE HOOD AREA USING INTERSECTION COMMAND

3. THEN WE WILL PROJECT THE CROSS SECTION INTO SKETCH AND WILL MAKE THE SKETCH AS A CLOSED ONE.

4. AFTER THIS WE WILL FIND THE SECTION MODULUS USING SECTION INERTIA ANALYSIS TOOL.

HERE IS THE SECTION MODULUS OF HOOD DESIGN BEFORE OPTIMIZATION.

AS WE HAVE TO ALWAYS DESIGN FOR THE MINIMUM STRENTGH,FOR FACTOR OF SAFETY,SO WE WILL CONSIDER MOI MINIMUM HERE,

I_min – 2.70x 10^5 (mm^4)

Y = Total length / 2

= 877.16/2

=438.58 mm

Section Modulus = 2.70 x 10^5 / 438.58

= .615*10^3

So for this hood design section modulus is 0.615 x 10^3 mm^3

HERE IS THE SECTION MODULUS OF HOOD DESIGN AFTER OPTIMIZATION

HERE WE WILL TRY TO IMPROVE THE DEPTH OF EMBOSSES BY 0.5 mm

I_min – 2.75x 10^5 (mm^4)

Y = Total length / 2

= 877.16/2

=438.58 mm

Section Modulus = 2.75 x 10^5 / 438.58

= .627*10^3

So for this hood design section modulus is 0.627 x 10^3 mm^3

It is evident that if the section modulus is increased from 0.615 x 10^3 mm^3 to 0.627 x 10^3 by increasing the sectional area.

Conclusion

Strength of material is directly proportional to the moment of interia, thus increasing the sectional area increase the increases strength of component.

Thus sectional modulus for hood design is calculated and optimized design is also done to increase the section modulus of the hood.