The Nonlinear Finite Element Toolbox (NLFET)

NLFET is a nonlinear finite element toolbox for MATLAB released under the GNU General Public License (GPL). The toolbox provides a framework for setting up, solving, and interpreting results for nonlinear static and dynamic finite element analysis.
- Manual – A short overview of NLFET in PDF format.
- Download – The source code for the toolbox in tar gzip format (WinZip should be able to extract this).
- Single Bay Example – Example code using the single bay frame from “A Nonlinear Finite Element Toolbox for Structural Control” presented at the Third World Conference on Structural Control.
- util.tgz – Utility functions in tar gzip format that are necessary to get the toolbox to run and for the examples.
It is now possible to browse the CVS repository or access it using anonymous access.
Example code for a semiactive control system using MR dampers is also available. Please contact info@nlfet.org if interested.
If you would like to help in the development of NLFET, or if you have any questions, please contact matt@nlfet.org.
Popularity: 2% [?]
MATPOWER: A MATLAB Power System Simulation Package
Filed under: FEM, Mathematics, Mechanics, Optimization, Physics
I just found this package on the web, I am sure many people will find it interesting.

MATPOWER is a package of Matlab M-files for solving power flow and optimal power flow problems. It is intended as a simulation tool for researchers and educators that is easy to use and modify. MATPOWER is designed to give the best performance possible while keeping the code simple to understand and modify. It was initially developed as part
of the PowerWeb project.
Download MATPOWERYou will be asked to fill out a brief form the first time you download from this site. See also Optional Packages below. |
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Getting Started
System Requirements
To use MATPOWER you will need:
- Matlab version 6 or later
- Matlab Optimization Toolbox (required only for some OPF algorithms)
Both are available from The MathWorks.
Note: Although it is likely that most things work fine in MATLAB 5, this is not supported due to limited testing resources. MATPOWER 3.0 required MATLAB 5 and MATPOWER 2.0 and earlier required only MATLAB 4.
Installation
- Unzip the downloaded file.
- Place files in a location on your Matlab path.
- Start up Matlab.
Running MATPOWER
To run a simple Newton power flow on the 9-bus system specified in the file case9.m, with the default algorithm options, at the Matlab prompt, type:
runpf('case9')
To run an optimal power flow on the 30-bus system whose data is in case30.m, with the default algorithm options, at the Matlab prompt, type:
runopf('case30')
To run an optimal power flow on the same system, but with the option for MATPOWER to shut down (decommit) expensive generators, type:
runuopf('case30')
For help on other options and parameters, type:
help runpf
help runopf
help runuopf
help mpoption
help caseformat
To run the test suite, place the files in the ‘t’ subdirectory in your Matlab path, and type:
test_matpower
What’s New in Version 3.2
Below is a summary of the changes since version 3.0.0 of MATPOWER. See the CHANGES file in the docs directory for all the gory details.
New features:
- AC OPF formulation enhancements
- new generalized cost model
- piece-wise linear generator PQ capability curves
- branch angle difference constraints
- simplified interface for specifying additional linear constraints
- option to use current magnitude for line flow limits (Set OPF_FLOW_LIM to 2, fmincopf solver only)
- AC OPF solvers
- support for TSPOPF, a new optional package of three OPF solvers,
implemented as C MEX files, suitable for large scale systems - ability to specify initial value and bounds on user variables z
- support for TSPOPF, a new optional package of three OPF solvers,
- New (v. 2) case file format
- all data in a single struct
- generator PQ capability curves
- generator ramp rates
- branch angle difference limits
- New function to build DC PDTF matrix (makePTDF.m)
- Added 5 larger scale (> 2000 bus) cases for Polish system. (Thanks to Roman Korab).
- Improved identification of binding constraints in printout.
- Many new tests in test suite.
Bugs fixed:
- Phase shifters shifted the wrong direction, again (v.2 had it right).
- Fixed bug in pfsoln.m which caused incorrect value for Qg when Qmin == Qmax for all generators at a bus in power flow solution.
INCOMPATIBLE CHANGES:
- User supplied A matrix for general linear constraints in OPF no longer includes columns for helper variables for piecewise linear gen costs, and now requires columns for all x (OPF) variables.
- Changed the sign convention used for phase shifters to be consistent with PTI, PowerWorld, PSAT, etc. E.g. A phase shift of 10 deg now means the voltage at the “to” end is delayed by 10 degrees.
- Name of option 24 in mpoption changed from OPF_P_LINE_LIM to OPF_FLOW_LIM.
Documentation
There are two primary sources of documentation for MATPOWER.
- Matlab’s help command
- MATPOWER User’s Manual (in
PDF format)
The User’s Manual is included in the distribution (manual.pdf in docs directory) or it can be downloaded separately from the link above.
Each M-file has its own documentation which can be accessed by typing at the Matlab prompt:
help <name of M-file>
Documentation for the case data file format can be found by typing:
help caseformat
If something is still unclear after checking the manual and the
help, the source code is the documentation
Optional Packages
There are three optional packages to enhance the performance of MATPOWER that may be downloaded separately. MINOPF and BPMPDMEX have more restrictive licenses than MATPOWER. Please see the individual Terms of Use for details.
| TSPOPF | A package of three AC OPF solvers implemented as C MEX files. Suitable for larger scale problems. |
| MINOPF | A MINOS-based AC OPF solver implemented as a Fortran MEX file. |
| BPMPD_MEX | MEX-file version of the high performance BPMPD interior point LP and QP solver. Speeds up DC and LP-based OPF solvers, and improves robustness of MINOPF. |
These packages are distributed separately since each has it’s own license agreement and terms of use.
Mailing List
An e-mail list MATPOWER-L@cornell.edu has been set up
to facilitate discussion of MATPOWER. Only list subscribers are permitted to post to the list.
Feel free to use this list to discuss anything related to MATPOWER, to ask questions about MATPOWER, or to provide feedback to the developers of MATPOWER, such as bug reports, patches or ideas for improvements (though we make no guarantees about if/when they might be included).
Also, if you have any of your own Matlab power systems code that you would like to contribute, feel free to contact us via this list about making it available on the MATPOWER web site.
Joining the list
To join the MATPOWER mailing list, send an e-mail to lyris@cornell.edu with the following line in the body of the message, where “John Doe” is replaced by your real name.
join MATPOWER-L "John Doe"
Sending mail to the list
To send an e-mail to all of the subscribers of the MATPOWER mailing list, simply address your e-mail to MATPOWER-L@cornell.edu. Only subscribers are permitted to send e-mail to the list.
Leaving the list
You can unsubscribe from the list at any time by sending an e-mail to lyris@cornell.edu with the following line in the body of the message.
leave MATPOWER-L
Popularity: 1% [?]
Structured Tedrahedral Mesh Generation
Popularity: 23% [?]
Twist Analisys of “Not Standard Sections”
Popularity: 16% [?]
Geodetic Dome
This is a simple linear fem analysis of a 3D truss structure. Displacements, stress and strain are calculated.
It Can be used for any structure, you just need to have coordinates and connectivity data.
I tried to make the code the more readeable I could. This way user can change it and make it closer to his own purpose.
For any problems, question, suggestions just contact me at:
Download Now
Popularity: 14% [?]


















































