Frequency Analysis of a rotating shaft

AIM: To find out the critical frequencies of a rotating shaft in Solidworks.

OBJECTIVE:

• To create the model of rotating shaft in Solidworks using appropriate dimensions.
• To perform a frequency analysis.

INPUTS:

• Part type : Shaft with mounted flywheel
• Material : Alloy steel
• Fixture : Bearing fixture ob both the sides of the shaft
• load : 120rad/s centrifugal force (assumed).
• No of frequencies: 5
• Solver selection : Automatic(FFEplus/Direct sparse solver)

CAD MODEL:

• Dimensions of rotating shaft :

• Cad model:

EXPLANATION:

• First we create the model with appropriate dimensions.
• Then we create a new study and select the frequency simulation.
• Then we select the material that is alloy steel.
• Then we apply bearing fixture on both the stepped face of the rod and then we apply a centrifugal force of 120 rad/s.
• Then we create a fine mesh.
• Further we select the frequency setting option ,where we select the frequency as 5 and the set the solver to automatic
• Then we run the simulation and get the required results.

OUPUTS:

• Mode 1:

• Mode 2:

• Mode 3:

• Mode 4:

• Mode 5:

RESULTS:

MODE	FREQUENCY (Rad/sec)	FREQUENCY (Hertz)	Period (sec)
1	119.86	19.0761	0.052422
2	2100.9	334.37	0.0029907
3	2101	334.39	0.0029905
4	6473.3	1030.3	0.00097062
5	6474.6	1030.5	0.00097044

CONCLUSION:

The 5 frequencies are identified as resonant frequencies. This tells us that when a system is designed with the above part, it should avoid operation in these frequencies since failure to do so can lead to devastating failures due to resonance.