Section Modulus calculation and optimization

SECTION MODULUS CALCULATION AND OPTIMIZATION FOR HOOD

Section Modulus:

Section Modulus is a geometry property used in the design of components that are subjected to bending. It is the direct measure of strength of a sectional area of any object about a neutral axis.

It can be defined as the ratio of the moment of inertia of a section and the distance from the neutral axis to the extreme fiber of the section. It is denoted by a "S" and can be mathematically represented as below:

S = I / y

Where, S - Section Modulus at the considered fiber, (in mm³)

I - Area Moment of Inertia or Second Moment of Inertia (in mm⁴)

y - Distance between Neutral Axis to the consider fiber (in mm)

Calculation of Section Modulus for Hood:

From the Hood designed in the previous challenge, export the solid bodies using the 'Generate CATPart from Product' command and follow the below steps,

1. Create a positioned sketch on a plane for which the section modulus calculation has to be performed. Use the Intersect 3d elements command and edit the section to create a single closed profile.
   
2. Use fill boundary command to create a surface using the sketch profile
   
3. Use Measure Inertia command to find the Moment of Inertia of the section
   
4. Measure the length of the profile from center to end
   
5. Use both the values of Inertia and the length to calculate the Section Modulus of the Hood.

Section modulus can be calculated for the above readings as follows,

Minimum Moment of Inertia, I_min = 1.7948833x10⁶ mm⁴

Maximum Moment of Inertia, I_max = 6.77903742x10⁸ mm⁴

Half-length of the Section, y = 441.439 mm

Using the formula for calculating the Section Modulus S = I / y, we get

Section Modulus with Minimum Moment of Inertia, S_min = 4.06598x10³ mm³ = 4065.98 mm³

Section Modulus with Maximum Moment of Inertia S_max = 1535.667x10³ mm³ = 1535667.99 mm³

Upon altering the Hood Design by increasing the emboss height by 1mm and repeating the procedure as above, we get the readings as follows:

Section modulus can be calculated for the above readings as follows,

Minimum Moment of Inertia, I_min = 1.99823201x10³ mm⁴

Maximum Moment of Inertia, I_max = 7.40659601x10⁸ mm⁴

Half-length of the Section, y = 441.167 mm

Using the formula for calculating the Section Modulus S = I / y, we get

Section Modulus with Minimum Moment of Inertia, S_min = 4.529423x10³ mm³ = 4529.423 mm³

Section Modulus with Maximum Moment of Inertia S_max = 1678.864469x10³ mm³ = 1678864.469 mm³

Observations:

	Minimum Section Modulus (Smin)	Maximum Section Modulus (Smax)
Designed Section	4065.98 mm3	4529.423 mm3
Optimized Section	1535667.99 mm3	1678864.469 mm3

Conclusion:

Hence, it can be concluded that the Section Modulus of the Hood can be improved by increasing the cross-sectional area of the inner panel. As a result of which, the strength of the Hood is also increased. But this doesn't mean we can keep increasing the area to achieve higher section modulus which also results in compromising the efficiency by increasing the weight of the inner panel. It is to be noted that every aspect of the component is cross-referenced to get the optimum values.