Virtual Engineering Lab
[C.B.Price 28-01-14]
Installation
Download and unzip the file as indicated. You will find an installer file and a folder:
-
Installer file “UDKInstall-BHAM_LAB”
Folder “User Code”
Also, if you do not have MS Visual Studio installed on your machine, you will need to grab the” Visual C++
Redistributable” package and install it on your machine. Please do this before you continue.
Proceed as follows
1.
2.
3.
4.
Start the installer. When it is finishing it will ask if you want to launch. Do not select launch.
The installer will create a directory like this C:\UDK\BHAM_LAB
Copy the contents of the folder “User Code” into C:\UDK\BHAM_LAB\Binaries\Win32\UserCode
Navigate to the folder C:\UDK\BHAM_LAB\Binaries\Win32 and look for the “UDK.exe” application. Place a
short-cut to this on your desktop.
5. Find the shortcut, open up its properties and make sure that the “Target” is set exactly like this
C:\UDK\BHAM_LAB\Binaries\Win32\UDK.exe BHamLabRev2.udk?Game=MIH56.MIH56_GameInfo
This completes the set-up.
Execution
To run the VLab double left-click on the shortcut.
To close the VLab, hit the tab key , ( to bring up the console line), then type “quit”.
User Interface
There is a common (almost) user interface. This is outlined below for the principal experiments in the Lab. Each
experiment is activated by a left mouse click when the cross-hair targets the apparatus. When selected the
apparatus glows fluorescent-green for a second.
Vibration Absorber
Key bindings
Key
Function
F1
Toggles running of the experiment
F2
Resets the experiment to its starting state (parameters and initial conditions)
F11
Opens and closes the log file. A short message appears on the screen indicating the state
(open/closed) of the log file. This allows multiple log files with individual names (automatic) to be
created during a single experiment
n
Increases the excitation omega by a small amount
m
Decreases the excitation omega by a small amount
Changing the parameters during a running experiment. This is done by the following sequence:
-
Hit the tab key to open up the single-line console input
Type “setparam N X” where N is the parameter name and X is the required value. Note a single space
between “setparam” and “N” and also between “N” and “X”
Hit “Esc” to close the console and effect the changes
Parameter
Affect
omD
Sets the natural angular frequency of the driven absorber (damper)
omP
Sets the natural angular frequency of the principal (driven) mass
omExcit
Sets the excitation angular frequency
bD
Sets the damping coefficient for the damper
bP
Sets the damping coefficient for the principal mass
Default Parameters which can be changed in the configuration file UDKBhamLab.ini in the directory
C:\UDK\BHAM_LAB\UDKGame\Config.
This file must be edited before the Lab is activated.
Parameter
Default Value
Affect
omP
5.0
Natural frequency of principal mass
omD
5.2452
Natural frequency of the damper
omInit
5.0
Excitation frequency
massP
4.0
Mass of the principal beam
massDa
0.5
Mass of the damper
bP
0.0
Damping coefficient for the principal beam
bD
1.0911
Damping coefficient for the damper
E
5.0
Amplitude of excitation of the principal beam
Static-Dynamic Balance Experiment
Key bindings
Key
Function
F1
Toggles running of the experiment
F2
Resets the experiment to its starting state (parameters and initial conditions)
F3
Toggles the experiment into a “driven” or “free” mode.
F11
Opens and closes the log file. A short message appears on the screen indicating the state
(open/closed) of the log file. This allows multiple log files with individual names (automatic) to be
created during a single experiment
F12
Advances the solution of the system in one time increment. Used when the experiment is not
running (F1) and is useful to investigate initial configurations of the apparatus. Works in both
“driven” and “free” modes. In the “driven” mode the effect of rotation is included.
1
Toggle the presence of the first bar (leftmost) on the shaft
2
Toggles the presence of the second bar on the shaft
3
Toggles the presence of the third bar on the shaft
4
Toggles the presence of the fourth bar on the shaft
m
Nudges the shaft angle. Used to set up initial state of the experiment before running
n
Nudges the shaft angle in the opposite direction
Changing the parameters during a running experiment. This is done by the following sequence:
-
Hit the tab key to open up the single-line console input
Type “setparam N X” where N is the parameter name and X is the required value. Note a single space
between “setparam” and “N” and also between “N” and “X”
Hit “Esc” to close the console and effect the changes
Parameter
Affect
deltaT
Time increment for the ODE solver
omega
Natural frequency of shaft rotation when in the “driven” mode
loc1
Location of the first (leftmost) bar on the shaft. Defaults to -64 (shaft centre is 0)
loc2
Location of the second bar on the shaft. Defaults to -32
loc3
Location of the third bar on the shaft. Defaults to +32
Loc4
Location of the fourth bar on the shaft. Defaults to +64
Truss Experiments
The Virtual Lab contains three truss structures. These are built using descriptor files which can be specified by the
instructor or even the student. Details on how to do this are given below. These files must be named Truss1.txt,
Truss2.txt, Truss3.txt and must be located in the directory C:\UDK\BHAM_LAB\Binaries\Win32\UserCode.
In this experiment, the user interface is slightly different. To activate a truss, the “health vial” must be cross-haired
and left-clicked. During the experiment, cross-hairing a node or a link (spring) will display its associated parameters
and variables. To stop or restart the experiment, or to change global parameters then the “health vial” must be
selected.
Key bindings
Key
Function
F1
Toggles running of the experiment
F2
Resets the experiment to its starting state (parameters and initial conditions)
Changing the parameters during a running experiment. This is done by the following sequence:
-
Hit the tab key to open up the single-line console input
Type “setparam N X” where N is the parameter name and X is the required value. Note a single space
between “setparam” and “N” and also between “N” and “X”
Hit “Esc” to close the console and effect the changes
Parameter
Affect
stiffness
This specified the stiffness (k) of all the springs
damping
Damping coefficient associated with solving the node-link system as a dynamical system of
coupled non-linear ODEs.
rescale
Will rescale the size of the truss during the experiment, in order to accommodate large trusses
in the Lab. Values should of course be in the range 0.0 to 1.0.
“Watt” Centrifuge
Note these experiments are under development, yet students may benefit from conducting free experiments on these
and analysing the results.
These notes apply to the right-most centrifuge located in the main Virtual Lab room, and are correct at 21/08/13,
though will be subject to enhancement.
Key bindings
Key
Function
F1
Toggles running of the experiment
n
Increases the angular velocity of the shaft by a small amount
m
Decreases the angular velocity of the shaft by a small amount
Changing the parameters during a running experiment. This is done by the following sequence:
-
Hit the tab key to open up the single-line console input
Type “setparam N X” where N is the parameter name and X is the required value. Note a single space
between “setparam” and “N” and also between “N” and “X”
Hit “Esc” to close the console and effect the changes
Parameter
Affect
deltaT
Time interval for the numerical solver
damping
Damping coefficient associated with solving the system as a dynamical system of coupled nonlinear ODEs.