WS4_Running Suspension Analysis

7/27/2019 WS4_Running Suspension Analysis

http://slidepdf.com/reader/full/ws4running-suspension-analysis 1/12

WS4-1 ADM740, Workshop 4, May 2012

Copyright 2012 MSC.Software Corporation

WORKSHOP 4

RUNNING SUSPENSION ANAYLSIS









Running Suspension Analysis

● Problem statement

● In this workshop, you analyze and modify an assembly of a frontsuspension and steering subsystem for quasi-static simulation.

● You will learn how to carry out Dynamic Suspension Analysis.

Before the 2012 release, the Suspension Assembly was limited to

carry out only quasi-static simulation. Now, your suspension

assembly is simulated with Adams/Solver Simulate/Dynamic

command.

● You also create plot configuration file and use that to plot curves in

the Adams/Postprocessor.

● The workshop contains the following sections:

● To Run Quasi-Static Suspension Analysis● To Run Dynamic Suspension Analysis

● To Create Plot Configuration File






● To Run Quasi-Static Suspension Analysis:

● Go through Adams Online help -> Getting Started -> GettingStarted Using Adams/Car -> Suspension Analysis Tutorial.

Note:

You need to select steering_wheel_input to create plot in the

Adams/PostProcessor. This characteristic is beneath +testrig when

you switch to Adams/PostProcessor. Likewise, when you want to

plot scrub_radius, you can find that beneath +testrig.






● To Run Dynamic Suspension Analysis:

● This allows you to directly provide a RPCIII file or define View

Functions to specify Jack and Steering motion as a function of

displacement, force, etc.

● In this workshop, a Suspension Assembly consisting of a doublewishbone suspension and a rack and pinion steering system. The

dynamic suspension analysis is carried out to actuate the wheel

pads across a range of frequencies.

● We will look at the lower control arm bushing force in the Adams/Postprocessor.






● To Run Dynamic Suspension Analysis (Cont…):

● Here is the procedure to analyze a double wishbone suspension

with rigid lower control arm.

● Start Adams/Car , Select Standard Interface .

● Create a new Suspension assembly:

● File –>New –> Suspension Assembly

● Fill the dialog box as indicated below. To select the subsystems, Right-

click – Search - <acar_shared> to open the file browser.







● The suspension assembly should be displayed.

● To simulate using the Dynamic Solver Statements, go to

Simulate –> Suspension Analysis –> Dynamic

● You will use View Functions to define the vertical displacement

of the Jack. The function below steps up the amplitude from 10mm in bounce and rebound to 30 mm respectively with a

frequency of 4 Hz.







● Insert step(time,2,10*sin(4*pi*time),8,30*sin(4*pi*time)) into

both the left and right Vertical Input Function fields.

● Select OK.







● Animate and Review the results:

● From the Review menu, select Animation Controls

● Animation Controls dialog box will be displayed. Animate the model

and observe the change in the suspension travel.

● Plot the bushing force in the lca_front bushing:

● Hit the F8 key in Adams/Car to switch to Adams/PostProcessor

● Locate the bkl_lca_front_force and bkr_lca_front_force

REQUEST under user-defined REQUESTs:






● Plot the bushing force in the lca_front bushing (Cont…):

● The fz_front component corresponds to magnitude of the force inthe Z direction. Plot this quantity to obtain a figure similar to the one

below:







● Optional task:

● You would like to go through the below SimCompanion article to

see how the force changes by replacing the rigid lower control

arm by a flexible body. In addition, you can get to know how to

use the flex body swap dialog box to switch a rigid lower controlarm with a flexible one.

Note: The files needed for this task are provided in the

acar_training_MD.cdb database. You need not add the

database provided in the article separately.

ACR-004: Using the Dynamic Suspension Testrig

Solution#: KB8017768

http://simcompanion.mscsoftware.com/infocenter/index?page=content&id=KB8017768







● To Create Plot Configuration File:

● Basic plot configuration steps:

1. Run a suspension analysis in the Standard Interface.

2. Manually make plots in Adams/PostProcessor.

3. From the File menu, point to Export, and then select Plot

Configuration File, to save the plot configuration file (.plt) inplot_configs.tbl in your default writable database.

4. Re-run the analysis in Standard Interface.

5. From the Plot menu, select Create Plots, to load the plot

configuration file (.plt) in Adams/PostProcessor.

The same plots are made automatically with the plot

configuration file.


Documents

WS4_Running Suspension Analysis