Section Modulus calculation and optimization

SECTION MODULUS CALCULATION & OPTIMIZATION OF A HOOD

INTRODUCTION

Section Modulus is the ratio of total moment resisted by the section to the stress in the extreme fiber. It gives us an idea about how much of load the given strucure can take. If the section modulus increases the moment of resistance increases and hence its load bearing capacity.

The formula we are going to use to find the Section Modulus is,

S=I/y

• S - Section Modulus
• I - Moment of inertia value from the inertia analysis
• y - Distance from Neutral axix to outermost fiber (in this case we will take it from the center to the outer edge of hemmed outer panel)

The section we are going to take from the previously designed hood assembly is the frontal mid section because we are considering the condition of frontal crash. For Creating the 2D curve from solid or surface model in NX CAD we can use the intersection curve

SECTION MODULUS CALCULATION OF HOOD

S=I/y

• I (Min)= 1.405787e4 mm4
• y = 439.2378 mm

S= 1.405787e4/439.2378 = 32.005 mm3

SECTION MODULUS CALCULATION OF HOOD AFTER OPTIMIZATION

S=I/y

• I (Min)= 1.519278e4 mm4
• y = 439.2378

S= 1.519278/439.2378 = 34.588 mm3

RESULT

There is an increase in the Section Modulus Value after increasing the area of the hoof section by offseting the curves of the inner panel and increasing the emboss.

CONCLUSION

Thus the Section Modulus calculation has been done on the original section and the optimized section and found out that, as the Area of the section increases the section modulus also increases.