Section Modulus calculation and optimization

Aim: Calculate the Section Modulus of the Hood Design.

Formula:

Section Modulus:

            Section Modulus is a geometric property for a given cross-section to resist the bending motion. The higher the section modulus, the more resistance to bending is offered at that cross-section.

Procedure:

1. We will take a section of our hood assembly in the z-z axis.
2. We will use the Intersection command and intersect between the hood assembly and yz-plane.
3. We only want the top line of the hood's outer panel and the bottom line of the hood's inner panel so we will use split to cut all unwanted lines.
4. We will join all the gaps using the line command's point-point option.
5. Now we will create a surface by using the fill command inside the curve.
6. After creating the surface, we will use Measure Inertia 2D option in the Measure Inertia command which will give us Moment of Inertia (I).
7. To calculate the distance of the neutral axis, from the end of the object, we will measure the distance between two ends of the section and divide it by two.
8. We will put all the values we got in the given formula which will give us section modulus.

Modification:

1. To improve the section modulus of our cross-section, we will modify our section so that the value of inertia increases.
2. First we will offset a plane from the yz-axis for creating a sketch.
3. Now in the sketch we will project the line of the surface by using Project 3D Elements command.
4. After the project, we will isolate the sketch.
5. We cannot change the upper profile as it of outer hood panel surface so we will modify the lower profile.
6. We will offset the middle line by 1 mm, increasing our ‘I’ value.

Before

After

Original calculation

`S=1036000/242.5306`

S=4271.628mm^3

Modified Calculation

`S=1060000/242.5305`

S=4987.531mm^3