Frequency Analysis of a rotating shaft using Solidworks

AIM

To simulate the FEA frequency analysis on the rotating shaft.

INPUT FOR SIMULATION

INPUT	VALUES
Material	Alloy steel
Mesh size	2 mm
Analysis type	Frequency analysis

DESIGN DIMENSION

BODY OF CONTENT

Introduction

In physics, resonance describes the phenomenon of increased amplitude that occurs when the frequency of a periodically applied force is equal or close to a natural frequency of the system on which it acts. When an oscillating force is applied at a resonant frequency of a dynamical system, the system will oscillate at a higher amplitude than when the same force is applied at other, non-resonant frequencies.

Frequencies at which the response amplitude is a relative maximum are also known as resonant frequencies or resonance frequencies of the system. Small periodic forces that are near a resonant frequency of the system have the ability to produce large amplitude oscillations in the system due to the storage of vibrational energy.

STEPS FOR DESIGNING

Before starting drawing make sure that the unit system is in mm.

1. Firstly, draw the sketch and provide the dimension according to mention in the figure below. Make sure that the design is closed.

2. Now go to the extrusion feature and give the extrude dimension of 30mm.

3. Make a two concentric circle at the end of shaft to provide a bearing support of radius 18mm and 50mm radius.

4. Provide a extrude cut option for making support of bearing which is having a dimension of 30 mm.

5. Make a two concentric circle at the end of shaft to provide a bearing support of radius 18mm and 50mm radius.

6. Provide a extrude cut option for making support of bearing which is having a dimension of 30 mm.

7. Make a plane at the center of the shaft in order to make the disc at the center. Here I have make a circle of diameter of 200 mm.

8. Extrude the circle with 30mm in order to make circular disc.

9. Now the final design of the shaft having circular disc as shown in figure.

STEPS FOR FEA SIMULATION

For doing FEA analysis in Solidworks make sure that the simulation is enable in Add ins of the Solidworks.

1. Firstly, click on simulation option after that go to the new study option as mention in figure with the red colour.

2. Now the select the type of analysis which you want to do like static, dynamic, frequency etc as shown in figure after that click on ok button. Here I am going to study for frequency analysis.

3. Now you will enter in the window which you have selected for the analysis as shown in the figure below.

Now the option which we have to provide for doing analysis is highlighted with the red colour box in figure below. Both red colour box represents the same option.

4. Now right click on part and select apply material option as shown in the figure below.

5. After that one dialog box will appear, choose the material from the dialog box as per your requirement and click on apply button. Here I used alloy steel for the material. When you click on the apply option the colour of your design will change.

6. Now right click on fixture option and select the type of fixture which you want in your design as shown in the figure below. Here I am using bearing fixture option to provide bearing support at the both faces of the shaft in order to make it bearing support and click on ok button.

8. For meshing of the design we need to right click on mesh option and click on create mesh. After that there is two way to do meshing one is automatic and second is manual. Here I used for manual method and provide the size of mesh as 2 mm as shown in figure. Smaller the mesh size will give you more accurate result.

9. Because of meshing, the design looks different from the previous figure as shown in figure.

10. Now right click on the part and click on run option. The name may vary according to your design but to run the simulation we need to follow this step. When you click on run button it starts the simulation.

11. After completing the simulation the result will be displayed on the screen.

RESULT

Model Information

Mass:13.9261 kg

Volume:0.00180858 m^3

Density:7,700 kg/m^3

Weight:136.476 N

Model Reference	Properties	Components
	Name: Alloy Steel Model type: Linear Elastic Isotropic Default failure criterion: Max von Mises Stress Yield strength: 6.20422e+08 N/m^2 Tensile strength: 7.23826e+08 N/m^2 Mass density: 7,700 kg/m^3 Elastic modulus: 2.1e+11 N/m^2 Poisson's ratio: 0.28 Thermal expansion coefficient: 1.3e-05 /Kelvin	Shaft having rotating disc

Parameter	Values
Mesh size	2 mm
Total Nodes	1484668
Total Elements	1057994
Material	Alloy steel

There is different mode shape after frequency simulation

Mode 1. Minimum and Maximum amplitude are 0 and 0.312

Mode 2. Minimum and Maximum amplitude are 0 and 0.311

Mode 3. Minimum and Maximum amplitude are 3.052 x 10^-6 and 0.5213

Mode 4. Minimum and Maximum amplitude are 9.397 x 10^-5 and 0.6323

Mode 5. Minimum and Maximum amplitude are 1.239 x 10^-5 and 0.6218

Resonant frequencies

Frequency Number	Frequency (Rad/sec)	Resonant Frequency (Hertz)	Seconds
1	1,747.9	278.19	0.0035946
2	1,748	278.21	0.0035944
3	3,482	554.17	0.0018045
4	7,329.1	1,166.5	0.00085729
5	7,330.5	1,166.7	0.00085713

CONCLSION

1. The mode shape which I obtain is not same it varies in all direction as shown in the figure.
2. The frequency obtain is greater than resonance frequency.

REFERENCES

1. skill lync video lectures