一个很简单的adams整车分析教程.pdf

Full vehicle analyses:
The following tutorial will help you complete a full vehicle analysis using Adams/CAR. First, open Adams/CAR and change the working directory by clicking File/Select Directory from the main toolbar. Set the working directory to a folder on the C drive just as you did in the suspension analysis tutorial.
Next, open a full vehicle model. For this tutorial, we will be using the MDI_demo_vehicle. Click File/Open/Assembly. The Open Assembly dialog box will appear. Double click in the text entry area of the dialog box to open the select file navigation window. Select the
MDI_Demo_Vehicle and click “Open” in the select file window and click “OK” in the Open Assembly window.
The message window will appear and the assembly will open. Once the assembly is fully loaded, close the message window and the open assembly dialog box. Your screen should show the demo vehicle like the following screen shot.
Now that we have a full vehicle model opened, we can perform a full vehicle analysis on it. There are many different types of full vehicle analyses we can perform on our model. We can simulate straight line acceleration and braking, constant radius cornering, lane changes, and drifting. This exercise will simulate constant radius cornering at the vehicle’s lateral acceleration limits. Consult the help files for a description of the full vehicle analyses Adams/CAR has to offer. They are accessible by clicking Help/MSC.Adams help form the main toolbar.
This simulation can be very useful in comparing two different suspension setups. This simulation can be completed for both suspension designs. The maximum lateral accelerations can be compared, along with other parameters calculated by Adams/CAR. The comparison can help determine which design outperforms the other in a constant radius cornering test. The simulation will not be useful in predicting the maximum lateral acceleration of your vehicle model unless all of the vehicle’s systems are modeled accurately. This is why a comparative analysis will be more useful than an absolute analysis. This same procedure can be completed for all other full vehicle analyses to determine the strengths and weaknesses of each design relative to one another. Braking, jumping, and acceleration simulations can help to estimate forces in components such as control arms and spherical joints so these parts can be designed to withstand the forces they are likely to see.
First, we will complete a constant radius cornering analysis. To do this, click
Simulate/Full Vehicle Analysis/Cornering Events/Constant Radius Cornering from the main toolbar. See the image below.
This will open the Constant Radius Cornering dialog box. Enter the parameters according to the picture below. This will simulate the car driving around a circular track with a radius of 100 feet. The car will begin its travel at 20 mph and end at 50 mph. The car is not limited to travelling only on the track. If the car cannot handle the lateral acceleration of the maneuver, it may spin
out of control or just overshoot the turns.
After you have entered all of the above parameters, click “Apply”
The message window will appear and the simulation will begin. Once the simulation completes, close the message window and the constant radius cornering dialog box. Zoom out on the screen until you can see the entire track. Click review/Animation Controls on the main toolbar. This
will allow you to play an animation of the simulation. Play the simulation to see how the vehicle traverses the 100 foot radius track.
The car overshoots the track and pushes off of the outside edge of the circular track. This is an oversteer maneuver. This will be a good evaluative simulation to compare different suspension setups.
Now, we will open the postprocessing window and plot lateral acceleration versus time. This will give us an idea of the road holding capabilities for this vehicle.
Click “Review/Postprocessing window” from the main toolbar. The postprocessing window will
open. It should look like the following screenshot:
Now, in the postprocessing window, highlight the following:
Simulation – demo_CRC_test_crc
Filter – User Defined
Request – Chassis Accelerations
Component – Lateral
Now click the “Add Curves” button. You should get a plot like the following:。