Section Modulus calculation and optimization

                     A

            Project Report

                     of

      Study of section modulus            

                      of

              Hood Panel

 

By: Manish Kumar

 

 

 

 

 

 

 

Objective

To study the section modulus of the hood panel, improvise the section of the hood panel and again calculate the section modulus of the improvised section.

 

Introduction

Section Modulus is a geometric property used to calculate the bending stresses in a structural member.

There are two types of section moduli:

<!-- [if !supportLists]-->a.   <!--[endif]-->Elastic section modulus

  Elastic section modulus applies to designs that are within        the elastic limit of a material, which is the most common case. Often elastic is referred to as simply “section modulus”. Elastic section modulus is calculated when we are to use the material behaviour till the yield point. 

<!-- [if !supportLists]-->b.   <!--[endif]-->Plastic section modulus.

The plastic section modulus is used for materials where the elastic yield is acceptable and the plastic behaviour is considered to be an acceptable range.

 

 

Mathematically

It is the ratio of area moment inertia about the neutral axis and to the distance of outermost fiber from the neutral axis.

              Z= I/Y

     Z= section modulus

     I = moment of inertia about the neutral axis.

     Y= distance of neutral axis from outermost fiber.

Area moment of inertia(I)

It is the resistance of a bare cross section towards the bending of the component.

Bending equation

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Taking the first two equation

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                                     M=     <!-- [if gte vml 1]> <![endif]--><!-- [if !vml]--><!--[endif]-->

                                    Z = I/Y

Where

                  M= bending Moment

                    Z= section modulus

                Y= Distance between neutral axis and outer fibre of the assembly.

Section modulus of the hood assembly

 

Procedure

Creating a datum plane at the centre of the assembly.

Creating the intersection curve of the hood assembly and the datum plane.

Using the section inertia analysis command on nx cad

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The value

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For the above section

I max= 8.968*10^7(mm^4)

I min= 2.733*10^5(mm^4)

Y= total length of the cross section/2( as neutral axis at the    

   centre)

                =876.1096/2

                      =438.548mm

  Section modulus= I /Y

  Smax = 8.968*10^7/438.548

             =2.044*10^5(mm^3)

S min= 2.733*10^7/438.548

         = 6.31*10^2(mm^3)

So, for the hood assembly the section modulus range is

      6.31*10^2(mm^3) 2.044*10^5(mm^3)

 

 

 

 

 

 

Optimising the section

The improved section

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The Value

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   Imax= 8.9522*10^7(mm^4)

   Imin= 2.7740*10^5(mm^4)

     Y= 438.548mm

S max= 8.9522*10^7/438.548

           =2.04*10^5(mm^3)

Smin= 2.7740*10^5/438.548

        = 6.32*10^2(mm^3)

So, for the hood assembly the optimised section modulus range is

      6.32*10^2(mm^3) 2.046*10^5(mm^3)

Application of the section Modulus

Section modulus is the direct measure of the strength of the steel. Bending a steel section that has a larger section modulus than another will be stronger and harder to bend. Section modulus is a geometric property for a given cross-section used in the design of flexural members.

Conclusion

The section modulus of the improved section is more than that of the initial section.

Sir 

The Link of the Zip file is

https://drive.google.com/drive/folders/14QoqRVD8O15RUlkgm2a08Cz3m3zZzmkT?usp=drive_link