I have added a feature for a two-degree-of-freedom system subjected to an applied force to the Matlab GUI package. The applied force options are steady-state sine, arbitrary time history and PSD.
Matlab script: Vibrationdata Signal Analysis Package
The new feature can be accessed via:
Vibrationdata > Miscellaneous > Structural Dynamics > Spring-Mass Systems > Two-DOF System Applied Force
* * *
Here are some related papers:
Calculating Transfer Functions from Normal Modes
An Introduction to Frequency Response Functions
Semidefinite System Force
General Coordinate Method
* * *
See also: Two-degree-of-freedom Systems
– Tom Irvine

Hello Tom,
Thanks again for all you are doing with the webinars and Matlab GUI.
I downloaded the latest GUI package (4_29_15) and tried to run this but was not able to do so. When I clicked on any of the “Select” buttons to select a configuration I got an error. The following is the response in the workspace for the fixed-fixed configuration:
>> vibrationdata
Undefined function or variable ‘two_dof_system_c_force’.
Error in vibrationdata_two_dof_force>pushbutton_select_c_Callback (line 160)
handles.s= two_dof_system_c_force;
Error in gui_mainfcn (line 95)
feval(varargin{:});
Error in vibrationdata_two_dof_force (line 42)
gui_mainfcn(gui_State, varargin{:});
Error in
@(hObject,eventdata)vibrationdata_two_dof_force(‘pushbutton_select_c_Callback’,hObject,eventdata,guidata(hObject))
Error while evaluating UIControl Callback
>>
Richard
I added the missing file to:
https://drive.google.com/file/d/0Bw1VlHh5X_tTSURUZmZHTkZ2b0E/view?usp=sharing
Please let me know if you find any other problems.
Thank you,
Tom Irvine