Adams Car Package > Adams Car Ride > Dialog Box - F1 Help > Full-Vehicle Vibration Analysis: ARIDE_FOUR_POST_TESTRIG

Full-Vehicle Vibration Analysis: ARIDE_FOUR_POST_TESTRIG

Ride -> Full-Vehicle Vibration Analysis -> Four-Post Test Rig
Sets up a full-vehicle vibration analysis. To use this dialog box, you must have a license for Adams Vibration. If you have access to the Adams Vibration plugin, it loads when the Adams Ride plugin loads.
 
For the option:
Do the following:
Full-Vehicle Assembly
Select the full-vehicle assembly you want to analyze.
Output Prefix
Enter a string that specifies the Analysis Output Name. The string can contain only alphanumeric characters and underscores (_).
Input Location
Adams Car Ride automatically creates vibration input channels. Depending on the actuation type chosen (below), the channels drive each pad of the rig with a kinematic input below each tire contact patch, to enable you to identify the vehicle response to road roughness inputs, or they drive wheel centers with a force input. At the same time, Adams Car Ride automatically creates vibration output channels to enable you to analyze the response at key points on the vehicle, such as the wheel centers and strut (damper) top mounts. In addition, you can add vibration output channels to specific locations on your model.
Input Direction
Adams Car Ride creates vibration input channels (actuators) that act in the vertical direction (only).
Actuation Type
Select the type of input the kinematic vibration actuators should provide in the test rig. As typical road spectra are approximately flat when plotted against velocity, we recommend the velocity input. However, the available options are:
■displacement
■velocity
■acceleration
■force (If you select Input Location as wheel centers this option will be displayed)
Vehicle Constraint
Select one of the following:
■No constraint
■xy constraint at body cog: The movements of the body of the vehicle will be limited by activating the JPRIM's body_stake and the yaw_stake
Actuator properties (for Left Front, Right Front, Left Rear, and Right Rear)
Specify the magnitude and phase (in degrees) of the input at each corner of the vehicle, in the units of the excitation quantities you selected for Actuation Type. By setting these values, you define the mode of excitation of the vehicle during the vibration analysis.
Select one of the following to define the actuators properties:
■Swept Sine. See Entering Swept Sine Function for available options.
■PSD. (Power Spectral Density). See Entering PSD Function for available options.
■User. (User-Defined Function). See Entering a User-Defined function for available options.
For example:
■If you choose swept sine excitational tire contact patches for all wheels, and set both front inputs to a magnitude of 1.0 and everything else to zero, you will excite the front axle only.
■If you set all magnitudes to 1.0, and the left channels to a phase of zero, but the right channels to a phase of 180 degrees, you will excite the vehicle with rolling motion that excites the left and right side with equal and opposite displacement or force (depending on whether you selected a kinematic or a force excitation above).
These values will have no influence on any transfer-function analyses, which present the output per unit input for every possible pair of input channel and output channel. The values will, however, influence frequency-response analyses, which present the system output that occurs because of the sum of all inputs (and the system transfer functions), considering both the phase and magnitude of those inputs.
Plot Actuator
Select to open the Actuator Preview Plot dialog box where you can see the plot of your actuator without running a simulation.
Only available when modifying an input channel.