# OS-SL-T: 1020 Fatigue Analysis of a Universal Joint

This tutorial demonstrates the creation of finite elements on a given CAD geometry of a universal joint.

Before you begin, copy the file(s) used in this tutorial to your working directory.

The application of boundary conditions and a finite element analysis of the problem is explained. Post-processing tools are used to determine the fatigue life of the joint due to static loading.

The following exercises are included:
• Set up the problem in SimLab
• Apply Loads and Boundary Conditions
• Solve the job
• View the results

Launch SimLab.

## Import the Model

1. From the menu bar, click File > Import > Database.
An Import File dialog opens.
2. Select the Universal_Joint.gda file you saved to your working directory from the Universal_Joint.zip file.
3. Click Open.
The Universal_Joint.zip database is loaded into SimLab. The .gda file only contains geometric data.

## Create Solution

1. From the Assembly tab of the Model Browser, select the Universal Joint and RBE bodies.
2. From the Solutions ribbon, Physics group, click the Structural tool.
The Create Solution dialog opens.
3. In the Create Solution dialog, define the following options:
2. For Solver, select OptiStruct.
3. For Solution type, select Linear Static.
4. Click OK.
In the Solutions tab of the Model Browser, an OptiStruct – Linear Static solution with the selected bodies is created.

## Create Materials and Properties

### Create Material

1. From the Analysis ribbon, Property group, click the Material tool.
The Material dialog opens.
2. In the Material dialog, enter the values as shown below and click OK.
The Fatigue material is created in the Property tab of the Model Browser.

### Create Property

1. From the Analysis ribbon, Property group, click the Property tool.
The Analysis Property dialog opens.
2. In the Analysis Property dialog, enter the values as shown below.
3. In the Assembly tab of the Model Browser, select Universal Joint.
4. In the Analysis Property dialog, click Apply.
5. Create a RBE property.
1. In the Analysis Property dialog, enter the values as shown below.
2. In the Assembly tab of the Model Browser, select RBE.
3. In the Analysis Property dialog, click OK.
The created properties are displayed in the Property tab of the Model Browser.

## Set Up Loads and Constraints

1. From the Analysis ribbon, Loads and Constraints group, click the Loads tool.
2. From the secondary tool set, open the Force and Moment tool.
The Force and Moment dialog opens.
3. In the modeling window, right-click and select RBE Node from the context menu.
4. In the modeling window, select the RBE main node attached to the Universal joint.
5. In the Force and Moment dialog, enter the values as shown below and click OK.
The force Torque Load is added to the current solution in the Solutions tab of the Model Browser.

### Define Constraints

1. From the Analysis ribbon, Loads and Constraints group, click the Constraints tool.
2. From the secondary tool set, select the Fixed tool.
The Fixed Constraint dialog opens.
3. In the Fixed Constraint dialog, enter the values as shown below.
4. In the modeling window, select the faces of the Universal Joint body.
5. In the Fixed Constraint dialog, click OK.

## Define Fatigue Solution

1. From the Solutions ribbon, Application group, click the Fatigue tool.
The Fatigue dialog opens.
2. In the Fatigue dialog, enter the values as shown below and click OK.
The Fatigue Solution is created in the Solution tab of the Model Browser.
3. From the Analysis ribbon, Loads group, click the Fatigue tool.

## Solve and View Results

### Solve the Solution

1. In the Solutions tab of the modeling window, right-click on Results under the Static Loading solution and select Update from the context menu.
The Solution begins to solve.
2. Right-click on Results under the Fatigue solution and select Update from the context menu.
The solution begins to solve.
The results are automatically loaded back into the database.

### Interpret the Results

The results are automatically loaded in the modeling window.

1. Use the Results panel to change the result component.
2. In the Solutions tab of the Model Browser, right-click Results under the Static Loading solution and select Display from the context menu.