Full-Vehicle Analysis: Frequency Response

Full-Vehicle Assembly

Select the Full-Vehicle Assembly you want to analyze. The menu lists all full-vehicle assemblies currently open in your session.

Assembly Variant

Select the assembly variant you want to analyze. The menu lists all full-vehicle assembly variants of the chosen assembly.

Switches to the selected variant and adds the required testrig as needed.

Output Prefix

Enter a string that specifies the Analysis Output Name. The string can contain only alphanumeric characters and underscores (_). Adams Car appends the suffix _frs to form the complete analysis name. For example, if you enter test_45 as the output prefix, the analysis name becomes test_45_frs.

Solver Settings File

Select one or more files (extension .ssf) defining the solver settings to be temporarily applied for this simulation (optional).

Opens the Solver Settings File (extension .ssf) editor dialog box.

End Time

Specify the time (in seconds) at which the analysis ends.

Number of Steps / Step Size / Step Frequency

Select either of the following:

Simulation Mode

Select interactive, background, graphical, files or event only.

See Mode of Simulation: Interactive, Mode of Simulation: Graphical, Mode of Simulation: Background, Mode of Simulation: Files_only, Mode of Simulation: Event_only.

Road Data File

Enter the name of a file that contains road data information. The tire subsystems use this information to calculate the tire/road interaction forces.

Tips on Entering File Names in Text Boxes

Import and visualize road graphics from file.

Remove road or path graphics.

View road / path file in info window.

Edit road / path file in road builder or text editor.

Gear Position

Specify the initial transmission gear for the analysis. The powertrain subsystem uses this parameter that generally acts as a gain for the throttle-demand output from the cruise control. The gear remains constant for the entire analysis, regardless of the selection for the Cruise Control.

Adams Car stores the gear ratios in the powertrain subsystem.

Suggested Gear Position based on desired Initial Velocity (or equivalent lateral acceleration and curvature radius for constant radius cornering events). The button suggests the gear position for the event in order for the engine speed to be in the range between stall speed and max revolution limit.

Enter the velocity of the vehicle in the units specified in the pull-down menu to the right of the Velocity text box.

Input Type

Select one of the following:

If you select Pulse, Adams Car displays the following option:

Lateral Acceleration

Enter lateral acceleration in G’s from which steering wheel angle is determined and that will be maintained during analysis

Steering Wheel Angle

Enter steering wheel angle in degrees

Pulse Duration

Enter pulse time in seconds

If you select Step/Discrete Sine, Adams Car displays the following option:

Lateral Acceleration

Enter lateral acceleration in G’s from which steering wheel angle is determined and that will be maintained during analysis

Steering Wheel Angle

Enter steering wheel angle in degrees

Method as Lateral Acceleration will display the following option:

Lateral Acceleration

Enter lateral acceleration in G’s from which steering wheel angle is determined and that will be maintained during analysis

Method as Steering Wheel Angle will display the following option:

Steering Wheel Angle

Enter steering wheel angle in degrees

Selecting Frequency Inputs toggle button will display the following option:

Initial Frequency

Enter the initial frequency of the steering input. The frequency can be described as the number of cycles per unit time.

Maximum Frequency

Enter the maximum allowable frequency of the steering input

Frequency Rate

Enter the rate of change of the frequency as a function of time.

Start Time

Enter a real value that specifies the time at which the swept sine input is to start.

If you select Spline, Adams Car displays the following option:

Duration of maneuver

Specify the time, in seconds, at which the analysis ends.

Driver Data File

Select a driver data file (.dcd) that defines an open- or closed-loop speed controller.

Learn about Working with Driver Control Data Files (.dcd).

Quasi-Static Straight-Line Setup

Select to perform a quasi-static prephase analysis before running the transient analysis on your full-vehicle assemblies.

If you do not select this option, Adams Car performs a SETTLE analysis.

For more information about the different quasi-static setup method keywords (such as SETTLE and STRAIGHT), see Structure of Event Files.

Create Event Log File

Select if you want Adams Car to write information about the assembled model and analysis to an Analysis Log File.

Add Vehicle Dynamics Requests

Activates requests computing certain vehicle dynamics outputs during the full vehicle event.

Some of these additional requests are required for standard post-processing (reports and plots).

Compute Characteristic Values

Activates requests computing suspension and steering characteristics during the full vehicle event.

The additional requests are equivalent to those previously already available for suspension analysis.

See Output of Suspension Analyses in Adams Car - Running Analysis for more details.

Select to display a dialog box where you can add multi-line comments to any entity, to describe its purpose and function. Adams Car displays different comments dialog boxes, depending on the entity type for which you want to record comments:

Learn about Recording Comments.

Select to display an Alignment dialog box where you can set toe, camber and caster alignment values.