OS-SL-T: 1010 Brake Squeal Analysis
This tutorial demonstrates the creation of finite elements on a given CAD geometry of a brake assembly.
Before you begin, copy the file(s) used in this tutorial to your
working directory.
Application of boundary conditions and a finite element analysis of the problem are explained. Post-processing tools are used to determine unstable modes produced during braking.
The following exercises are included:
- Set up the problem in SimLab
- Apply Loads and Boundary Conditions
- Solve the job
- View the results
Launch SimLab
Launch SimLab.
Import the Model
-
From the menu bar, click .
An Import File dialog opens.
- Select the Brake_Model.gda file you saved to your working directory from the Brake_Squeal.zip file.
-
Click Open.
The Brake_Model.gda database is loaded into SimLab. The .gda file only contains geometric data.
Create Solution
-
From the Solutions ribbon,
Physics group, click the
Structural tool.
The Create Solution dialog opens.
-
In the Create Solution dialog, define the following
options:
Create Materials and Properties
Create Material
-
From the Analysis ribbon,
Property group, click the
Material tool.
The Material dialog opens.
-
In the Material dialog, enter the values as shown below
and click Apply.
The Back plate material is created in the Property tab of the Model Browser.
-
Create three more materials.
Create Property
-
From the Analysis ribbon,
Property group, click the
Property tool.
The Analysis Property dialog opens.
-
In the Analysis Property dialog, enter the values as shown
below.
-
In the Assembly tab of the Model Browser, select
INNER-BACKPLATE and
OUTER-BACKPLATE.
- In the Analysis Property dialog, click Apply.
-
Create an Insulators property.
-
Create a Rotor property.
-
Create a Pad property.
- In the Analysis Property dialog, click Cancel.
Set Up Loads and Constraints
Create Local Coordinate
- From the Analysis ribbon, Loads and Constraints group, click the Coordinate tool.
-
From the secondary tool set, select the Create
tool.
The Create Coordinate System dialog opens.
-
In the Create Coordinate System dialog, enter the values
as shown below.
-
In the modeling window, select the cylindrical face
from the Rotor.
- In the Create Coordinate System dialog, click OK.
Create Contacts
Contacts are created between the Rotor and Pads to simulate the braking action of the pads against the rotor.
-
From the Analysis ribbon, Loads and
Constraints group, click the Contact
tool.
The Define Contact dialog opens.
-
In the Define Contact dialog, enter the values as shown
below.
-
In the Define Contact dialog, select the line edit field
for Main faces.
The line edit field is highlighted.
-
In the modeling window, select the Rotor
faces.
-
In the Define Contact dialog, select the line edit field
for Secondary faces.
The line edit field is highlighted.
-
In the modeling window, select the Pad
faces.
-
In the Define Contact dialog, select
Create for the Friction coefficient table
parameter.
The Create Table dialog opens.
-
In the Create Table dialog, enter the values as shown
below and click OK.
Tip: Press Enter within the table cells to add additional rows.
- In the Define Contact dialog, click OK.
Create Loadcase
-
In the Solutions tab of the Model Browser, right-click
the Brake Squeal Analysis solution and select
Define using Load case from the context menu.
A loadcase is created and added in the Solutions tab of the Model Browser.
-
Right-click on LoadCase1, select
Rename from the context menu,
and enter Brake Pressure.
The Loads and Constraints pertaining to simulate the braking action of the pads against the rotor are added in the Brake Pressure loadcase.
-
Create a Disc Rotation loadcase.
- Right-click on LoadCase and selection Create Loadcase from the context menu.
- Right-click on the LoadCase2, select Rename from the context menu, and enter Disc Rotation.
-
Create a Brake Squeal loadcase.
- Right-click on LoadCase and selection Create Loadcase from the context menu.
- Right-click on LoadCase3, select Rename from the context menu, and enter Brake Squeal.
- Right-click on Type and select .
Define Brake Pressure
-
In the Solutions tab of the Model Browser, right-click
the Brake Pressure loadcase and select Set
Current from the context menu.
The Brake Pressure loadcase is set to current. All newly created loads and constraints will be added to the current loadcase.
- From the Analysis ribbon, Loads and Constraints group, click the Loads tool.
-
From the secondary tool set, select the Pressure
tool.
The Pressure dialog opens.
-
In the Pressure dialog, enter the values as shown
below.
-
In the modeling window, select the top faces of both
Insulators.
- In the Pressure dialog, click OK.
Create Constraints
- From the Analysis ribbon, Loads and Constraints group, click the Constraints tool.
-
From the secondary tool set, click the Fixed tool.
The Fixed Constraint dialog opens.
-
In the Fixed Constraint dialog, enter the values as shown
below.
-
In the modeling window, select the side faces of both
back plates.
-
In the Fixed Constraint dialog, click Apply.
The Back plate constraint is added to the current loadcase in the Solutions tab of the Model Browser.
-
Create a Rotor Fixed constraint.
The Rotor Fixed constraint is added to the current loadcase in the Solutions tab of the Model Browser.
Define Enforced Displacement
The enforced displacement is used to simulate the rotation of the rotor against the brake pads.
- In the Solutions tab of the Model Browser, right-click on the Disc Rotation loadcase and select Set Current from the context menu.
-
Right-click on the Rotor Fixed constraint under the
Brake Pressure loadcase and select Add to current
Loadcase from the context menu.
The Rotor Fixed constraint is added to the Disc Rotation loadcase.
- Right-click on the Brake Pressure constraint under the Brake Pressure loadcase and select Add to current Loadcase from the context menu.
- Right-click on the Back Plate constraint under the Brake Pressure loadcase and select Add to current Loadcase from the context menu.
- From the Analysis ribbon, Loads and Constraints group, click the Constraints tool.
-
From the secondary tool set, click the Enforced
tool.
The Enforced Constraint dialog opens.
-
In the Enforced Constraint dialog, enter the values as
shown below.
-
In the modeling window, select the cylindrical face at
the center of the rotor.
- In the Enforced Constraint dialog, click OK.
Define Brake Squeal Loadcase
- In the Solutions tab of the Model Browser, right-click on the Brake Squeal loadcase and select Set Current from the context menu.
- Right-click on the Rotor Fixed constraint under the Disc Rotation loadcase and select Add to current Loadcase from the context menu.
- Right-click on the Back Plate constraint under the Disc Rotation loadcase and select Add to current Loadcase from the context menu.
- Right-click on the Brake Squeal loadcase and select Text Data from the context menu.
-
In the Text Data dialog, enter
DISPLACEMENT(UNSTABLE) = ALL and click
Save.
Define Loadcase Parameters and Output Requests
-
In the Solutions tab of the Model Browser, right-click
on the Brake Pressure loadcase and select
Loadcase Parameters from the context menu.
The Loadcase Parameters dialog opens.
-
In the Loadcase Parameters dialog, enter the values as
shown below and click OK.
-
Right-click on the Brake Pressure loadcase, and select
Result Request from the context menu.
The Result Request dialog opens.
-
In the Result Request dialog, enter the values as shown
below and click OK.
-
Create loadcase parameters and output requests for the Disc Rotation
loadcase.
-
Create loadcase parameters for the Brake Squeal loadcase.
Create Solution Parameters
-
In the Solutions tab of the Model Browser, right-click
on the Brake Squeal Analysis solution and select
Solution Parameters from the context menu.
The Solution Parameters dialog opens.
-
In the Solution Parameters dialog, enter the values as
shown below and click OK.
Solve and View Results
Solve the Solution
In the Solutions tab of the modeling window,
right-click on Results and select
Update from the context menu.
The Solution begins to solve.
Interpret the Results
The results are automatically loaded in the modeling window.
By default, the results data for the first loadcase will be displayed. Use the
Results panel to change the loadcases, result component, and time steps.Animate the results using the Animation toolbar at the bottom of the modeling window.
-
In the Results panel, change the results loadcase from Brake Pressure to
Disc Rotation.
The stress developed due to the combined action of Disc roation and braking can be inferred.
-
Change the results loadcase from Disc Rotation to Brake
Squeal.
In the Brake Squeal loadcase, three unstable modes (Mode 8, Mode 14, and Mode 22) are produced at frequencies of 1950.32 Hz, 3270.60 Hz, and 4776.90 Hz, respectively.
- Optional: From the Animation toolbar in the modeling window, select XYZ Deformation to visualize the mode shapes.