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LAB ASSIGMENT #5 New Mexico State University

Mechanical and Aerospace Engineering Department

Spring 2016

The dimension of the support’s geometry and the wall’s geometry are:

Steps of FEA:

1.  Building up 3D beam model

Support

Wall

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LAB ASSIGMENT #5 New Mexico State University

Mechanical and Aerospace Engineering Department

Spring 2016

2. 

Defining the material for the Support and the wall as Alloy steel then define the wall as

rigid body.

- Support_1

-  Wall

3.  Defining contact between the support and the wall as No Penetration. 

8/18/2019 New Mexico State University Project

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LAB ASSIGMENT #5 New Mexico State University

Mechanical and Aerospace Engineering Department

Spring 2016

4. 

Defining the bolted connection as counterbore bolt and nut for the four bolts.

2

3

4

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LAB ASSIGMENT #5 New Mexico State University

Mechanical and Aerospace Engineering Department

Spring 2016

5. 

Defining fixed geometry at the wall

6.  Defining force

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LAB ASSIGMENT #5 New Mexico State University

Mechanical and Aerospace Engineering Department

Spring 2016

7. 

Meshing, using fine mesh to get accurate result

8.  Result

-  Displacement

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LAB ASSIGMENT #5 New Mexico State University

Mechanical and Aerospace Engineering Department

Spring 2016

-  Stress

9.  Bolt Forces List

8/18/2019 New Mexico State University Project

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LAB ASSIGMENT #5 New Mexico State University

Mechanical and Aerospace Engineering Department

Spring 2016

Calculation

1.  Calculating bolt diameter from FEM result

-  The greatest axial load on bolt is 1381 N (bolt 3)

Axial strees on bolt 3:

 =

 

 

 

 

 = 8,286 mm2

-  The greatest shear force on bolt is 433,45 N (bolt 4)

Shear strees on bolt 4:

 =

 =

 

 

 

 

 = 4,5 mm2

We choose the greatest  to make sure the factor factor of safty 3. So we use bolt

with   mm2. From standard bolt’s table we choose bolt with ≥ 8,286

mm2, and we get bolt with 4mm in nominal diameter.

8/18/2019 New Mexico State University Project

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LAB ASSIGMENT #5 New Mexico State University

Mechanical and Aerospace Engineering Department

Spring 2016

2.  Manual Calculation

-  Axial force bolt 1 and 3 can be solve with equilibrium moment equation:

R 1,3 x 60 = 1000 x 180

R 1,3 = 1500 N

-  The greatest axial load on bolt is 1381 N (bolt 3)

Axial strees on bolt 3:

 =

 

1,3

2,4

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LAB ASSIGMENT #5 New Mexico State University

Mechanical and Aerospace Engineering Department

Spring 2016

 

 

 

 = 9 mm2

From standard bolt’s table we choose bolt with  ≥ 9 mm2, and we get bolt with 5

mm in nominal diameter. 

3. 

Comparing the standard bolt diameter FE and manually (classical result).

Diff nominal diameter(%) =

 x 100% =

 x 100% = 20%

This result is quite large . but the actual results are calculated based on the difference

 .

Diff  (%) =

 x 100% =

 x 100% = 7,93%