Section Modulus calculation and optimization

AIM:

Use the Section from your Hood design and calculate the section modulus using the given formula.

OBJECTIVE:

• Calculate the section modulus for the hood design.
• Develop a new section that has improved the section modulus of the previous section
• And mention the changes that was made to increase the strength.

OBSERVATION:

Section modulus is a geometric property for a given cross-section used in the design of beams or flexural members. Other geometric properties used in design include area for tension and shear, radius of gyration for compression, and moment of inertia and polar moment of inertia for stiffness. Any relationship between these properties is highly dependent on the shape in question.

Section modulus is defined as the ratio of polar moment of inertia to the radius of the shaft or the distance from the neutral axis to the outer fibres.To calculate the section modulus of the hood design use the below formula,

S = I/y

S = Section Modulus

I = Moment of Inertia

y = distance between the neutral axis and the extreme end of the object

PROCEDURE:

• First select the intersection curve to get a sectional view of the hood by selecting the faces and the ZX plane.

• Next use extract geometry to use the composite curve option to derive the sectional layout.

• Now the gaps between sections should be rectified, by using the lines option fill the holes sectional views.

• Create a datum plane for the intersection of hood inner and outer panel for the sectional layout.

• Then create a line between the panels perpendicular to them.

• Trim the excess curve by using trim curve and select the composite curve and created line between panels.

• Finally follow the process with sectional inertia analysis option and select the sectional lines.

• Follow the same procedure for the lateral front view of the hood design.

• Measured distance of the hood design (Y) at front view.

• The design optimized by using a slight change by creating a rectangular vent and fillet edges as 5 mm.

CALCULATION:

S = I/Y

S = Section Modulus

I = Moment of Inertia

y = distance between the neutral axis and the extreme end of the object = 874.7/2 = 437.35 mm

• calculate the section modulus for the given hood design for I = 1.4 * e+04 mm^4(min) and 4.7 * e+06 mm^4(max).

For minmum strength of the hood design

S = I/Y

S = 14000 / 437.35

S (min) = 32 mm^3

For maximum strength of the hood design

S = I/Y

S = 4700000 / 437.35

S (max) = 10746.5 mm^3

• calculate the section modulus for the optimized hood design for I = 1.5 * e+04 mm^4(min) and 5.2 * e+06 mm^4(max).

For minmum strength of the hood design

S = I/Y

S = 15000 / 437.35

S (min) = 34.3 mm^3

For maximum strength of the hood design

S = I/Y

S = 5200000 / 437.35

S (max) = 11890 mm^3

RESULT:

• The section modulus of the given hood design is minimum as 32 mm^3 and maximum as 10746.5 mm^3.

Given Hood design

• To poses a greater strength than the given hood design, we can create a rectangular slit at center and fillet edges as 5 mm.

Optimized Hood design

• The section modulus of the optimized hood design is minimum as 34.3 mm^3 and maximum as 11890 mm^3.