Defining a Restraint Excitation Set

This task will show you how to define the restraint excitation set in a:

• harmonic dynamic response analysis case
• transient dynamic response analysis case

Defining a restraint excitation set allows you to define an imposed motion of the support in the frequency domain or in the time domain.

Only available with the Generative Dynamic Response Analysis (GDY) product.

Harmonic Dynamic Response Case

Open the sample57_1.CATAnalysis document from the samples directory.

• Insert a Harmonic Dynamic Response Analysis Case (and choose a restraint excitation set).
• Define a white noise modulation or define a frequency modulation.

1. Double-click the restraint excitation object belonging to the harmonic dynamic response case.

   In this particular case, double-click Restraint Excitation.1. under the Harmonic Dynamic Response Case set. The Restraint Excitation Set dialog box appears. Name: gives the name of the restraint excitation set. If needed, you can modify it. Axis System: Type: Global: if you select the Global Axis system, the components field will be interpreted as relative to the fixed global rectangular coordinate system. User: if you select a user-defined axis system, the components will be interpreted as relative to the specified rectangular coordinate system. Current axis: lets you select the desired axis system. Local orientation: (Cartesian) the components are interpreted as relative to a fixed rectangular coordinate system aligned with the Cartesian coordinate directions of the User-defined Axis. Selection: Selected modulation: lets you select a white noise modulation or a frequency modulation. You cannot select a time modulation in a harmonic dynamic response analysis case. Selected acceleration: lets you select the acceleration that will be modulated. Selected phase: lets you specify the phase value. Degrees of freedom: gives you the list of the degrees of freedom, the associated modulation, acceleration and phase (T for translation and R for Rotation)

2. Set the desired parameters in the Restraint Excitation Set dialog box.

   In this particular example: Select the Global option as Axis System Type. Select Frequency Modulation.1 as Selected modulation. Enter 1m_s2 as Selected acceleration. Enter 1deg as Selected phase.

3. Press Enter to update the Restraint Excitation Set dialog box.

   The TX degree of freedom is defined and the Restraint Excitation Set dialog box appears as shown below: You can define other degrees of freedom. To do this:

4. Select an other degree of freedom.

   In this particular example, select the RY degree of freedom.

5. Set the different parameters (associated modulation, acceleration and phase).

   In this particular example: Select the White Noise.1 modulation as Selected modulation. Enter 3rad_s2 as Selected acceleration. Enter 2deg as Selected phase.

6. Press Enter to update the Restraint Excitation Set dialog box.

   The RY degree of freedom is defined and the Restraint Excitation Set dialog box appears as shown below:

7. Click OK.

Transient Dynamic Response Case

Open the sample57_1.CATAnalysis document from the samples directory.

• Insert a Transient Dynamic Response Analysis Case (and choose a restraint excitation set).
• Define a time modulation.

1. Double-click the restraint excitation belonging to a transient dynamic response case.

   In this particular case, double-click Restraint Excitation.1. The Restraint Excitation Set dialog box appears. Name: gives the name of the restraint excitation set. If needed, you can modify it. Axis System: Type: Global: if you select the Global Axis system, the components field will be interpreted as relative to the fixed global rectangular coordinate system. User: if you select a User-defined Axis system, the components will be interpreted as relative to the specified rectangular coordinate system. Current axis: lets you select the desired axis system Local orientation: (Cartesian) the components are interpreted as relative to a fixed rectangular coordinate system aligned with the Cartesian coordinate directions of the User-defined Axis. Selection: Selected modulation: lets you select a time modulation. You cannot select a frequency modulation. Selected acceleration: lets you select the acceleration that will be modulated. Degrees of freedom: gives you the list of the degrees of freedom, the associated modulation, acceleration (T for translation)

2. Set the desired parameters in the Restraint Excitation Set dialog box.

   In this particular example: Select the Global option as Axis System Type. Select Time Modulation.1 as Selected modulation. Enter 1m_s2 as Selected acceleration.

3. Press Enter to update the Restraint Excitation Set dialog box.

   The Restraint Excitation Set dialog box appears as shown below: You can define other degrees of freedom. To do this:

4. Select an other degree of freedom.

   In this particular example, select the TY degree of freedom.

5. Set the different parameters (associated modulation and acceleration).

   In this particular example: Select the White Noise.1 modulation as Selected modulation. Enter 3rad_s2 as Selected acceleration.

6. Press Enter to update the Restraint Excitation Set dialog box.

   The TY degree of freedom is defined and the Restraint Excitation Set dialog box appears as shown below:

7. Click OK.