Damping Vibration of Cantileverexamples|products|Murata Software Co., Ltd.

Example36 Damping Vibration of Cantilever

General

  • A cantilever is mechanically loaded. After it is unloaded, it starts to vibrate. The vibrations decays over time.
     

  • The displacement and the mechanical stress are solved for each time step.
     

  • Unless specified in the list below, the default conditions will be applied.
     

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Analysis Space

Item

Settings

Analysis Space

3D

Model unit

mm

 

Analysis Conditions

Item

Settings

Solvers

Mechanical Stress Analysis [Galileo]

Analysis Type

Transient analysis

The transient analysis is set up as follows.

Tab

Setting Item

Settings

Transient Analysis Tab

Table

Calculation steps

Output steps

Time step [s]

5

1

0.002

100

1

0.0002

Rayleigh Damping Coefficients

Beta=0.0002

The load gradually increases in the first 5 steps. In the next 100 steps,

it is unloaded, and the damping vibration occurs.

0 – 0.01 [sec]: Loading period

0.01 – 0.03 [sec]: Vibration period

 

Model

Body Attributes and Materials

Body Number/Type

Body Attribute Name

Material Name

0/Sheet

Body_Attribute_001

002_Polycarbonate(PC)

Boundary Conditions

Boundary Condition Name/Topology

Tab

Boundary Condition Type

Settings

Fix/Face

Mechanical

Displacement

Select all X/Y/Z components.

UX=0, UY=0, UZ=0

Force/Face

Mechanical

Distributed face load

X=0, Y=0, Z=-0.5×10^5

 

Time Dependency: Yes

Time

Weight

0

0

0.01

1

0.101

0

10

0

 

The loading is removed instantaneously at 0.01[sec].

Tips on Analysis Conditions and Boundary Conditions

Perform a static analysis and obtain the adequate loading condition for the target displacement beforehand.

Perform a resonant analysis and obtain the adequate time steps for the expected vibration period.

Results

The displacement diagram below shows the deformation at 0.01[sec] (Mode number 5). The color gradation contour indicates the Z displacement.

 

Plotted below is the Z displacement of the cantilever tip in 0.01 to 0.03 [sec] (Mode numbers 5 through 105)

 

The vibration decays as the time passes.

 

The figure below shows the vibration when Beta is set to 0.

There is no decay.