Section Modulus calculation and optimization

Section Modulus Calculation

Introduction:

Section modulus is the property of the cross section that is used while design the beam, hood etc.,

1] Elastic section modulus: The elastic section modulus is applicable up to the yield point of material. It is used in most engineering applications. For general design, the elastic section modulus is used, applicable up to the yield point for most metals and other common materials.

Elastic section modulus is the ratio of moment of inertia about a neutral axis(I) and the maximum distance between the neutral axis and outermost fiber of beam(Y).

                       

                                                            S = I/Y

Where,
I = Moment of inertia (m⁴)
Y = Distance between neutral axes and outermost fiber (m)

 

Section Modulus calculation in nx cad:

1.Existing Hood design

            This section modulus was calculated for existing hood panel design by taking the cross section of hood inner and outer panel. Here Y is the extreme ends of the hood cross section.

MOI (Max) = 1.4e8 mm⁴

MOI (Min) = 8.25e4 mm⁴

Minimum value is considered to design the hood better. To improve the MOI we need to do changes in  the cross section.

2.Offset surface of hood inner and outer panel:

            Here the hood inner and outer panel surface offset outwards 0.3mm.This will improve the MOI. But if we change the dimensions then related parts dimensions also need to change. It could collapse entire design of other parts.

MOI (Max) = 1.5e8 mm⁴

MOI (Min) = 8.7e4 mm⁴

3. Increased curvature of outer panel:

            By increasing the curvature of outer panel will improve the MOI of hood.

MOI (Max) = 1.12e8 mm⁴

MOI (Min) = 2.95e5 mm⁴