professor ben schafer's thin-walled structures research group - johns hopkins university

 

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What's new (version 4.05)
Tutorials
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    Standalone version
    Matlab open source version
License and Distribution
Referencing CUFSM
Direct Strength Method

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Sponsors

Take me to the old 3.12 version

 


 

CUFSM 4.05

Elastic Buckling Analysis of Thin-walled Members
with general end boundary conditions

 

Thin-walled members, by their very nature, have the potential to suffer from a variety of cross-section stability problems. CUFSM employs the semi-analytical finite strip method to provide solutions for the cross-section stability of such members. The software has been successfully used by researchers, educators, students, and practicing engineers. While CUFSM is most commonly used for thin-walled cold-formed steel members, it has also been used for a large variety of other materials and applications. In this latest version the solution has been expanded to allow for general end boundary conditions.

 

Find the local, distortional and global buckling load of your member now! Use CUFSM.

 

Background
The semi-analytical finite strip method is a variant of the more common finite element method. A thin-walled cross-section is discretized into a series of longitudinal strips, or elements. Based on these strips elastic and geometric stiffness matrices can be formulated. The procedure is readily recognizable by anyone who has studied matrix analysis of structures, but is specialized to apply to plate deformations beyond conventional beam theory. A paper describing the finite strip method, as implemented in CUFSM3 is available (pdf) and now the new features of CUFSM4, which covers general end boundary conditions are also deatiled (pdf). The solution allows a user to explore all potential cross-section instabilities in a given member in an expedient and interactive manner.

 

What's new (version 4.05)
CUFSM 4.05 repreents a major change from CUFSM 3.12 that has been available for the last 4 years. CUFSM now applies to members with general end boundary conditions. The constrained finite strip method (cFSM) is also fully implemented in this version. Due to the changes some interface changes and improvements were also completed - the most major of which was to split "lengths and boundary conditions" on to their own page. The cFSM implemented in CUFSM is discussed briefly in this paper and this paper and the cFSM idea is also discussed further here CUFSM4.05 fixes several bugs related to saving and loading files.

 

Tutorials
Formal tutorials created and proofed by the writers of CUFSM are not yet availabl; however graduate student in the Thin-walled Structures Group have created new tutorials for CUFSM4 that can serve to help users learn the new capabilities and modified interface for CFUSM4.
..Videos frrom Kara Peterman: Signature curve, cFSM
..Powerpoint tutorial from Jiazhen Leng: CUFSM


For more tutorials See CUFSM 3.12 for tutorials all functions available in CUFSM 3.12 are available in CUFSM 4 though the interface has been updated in some cases.

Download CUFSM version 4.05
Standalone version for PCs and MACs

Windows 32-bit (shoudl run on 64 bit computers too)
Installation is a 2-step process
1. Download and install Matlab component runtime engine
2. Download and install CUFSM4.05 setup
Mac 64-bit
Installation is a 2-step process
1. Download and install Matlab component runtime engine
2. Download and install CUFSM4.05 setup

Matlab open source version for any platform
Download all m-files 4.05 source
    Installation: unzip the files to the directory of your choice. To run in matlab open the file cufsm4.m and then hit the run button on the toolbar in the matlab editor, OR, change directory in matlab to the directory you unzipped the files into by selecting the "..." button after the current directory listing, and then type "cufsm4" in the command window.
 

License and Distribution

CUFSM is open source, Academic Free License v 1.2. Please provide a reference to the author (Ben Schafer) and note the version you are using. Archive of older CUFSM versions are also available for download. Contact schafer@jhu.edu with problems.

 

Referencing CUFSM
CUFSM is open source, see license. However users of the software are asked to reference the software when they publish results using CUFSM. The currently recommended reference is the following summary paper:

Li, Z., Schafer, B.W. (2010) “Buckling analysis of cold-formed steel members with general boundary conditions using CUFSM: conventional and constrained finite strip methods.” Proceedings of the 20th Int;l. Spec. Conf. on Cold-Formed Steel Structures, St. Louis, MO. November, 2010. (pdf)

 

Direct Strength Method
The Direct Strength Method is a design method for cold-formed steel members that uses cross-section elastic buckling solutions, determined by tools such as CUFSM, as the primary input to the strength prediction. The Direct Strength Method was created in the Thin-walled Structures Research Group and much more information can be found on this page: DSM homepage.

 

Archive

All older versions of CUFSM, including supporting materials are available in the archive. Note CUFSM v2.5 and v2.6 provide standalone versions that run well on older PCs. CUFSM 3.12 is currently supported for XP PCs and available here.

 

Sponsors

Note, the materials developed to support CUFSM and the program CUFSM were both developed, in part, through the sponsorship of research projects with the American Iron and Steel Institute ( www.steel.org ) and the National Science Foundation ( www.nsf.gov ). Any opinions, findings, and conclusions or recommendations expressed in this material (or through this software) are those of the author and do not necessarily reflect the views of the National Science Foundation or the American Iron and Steel Institute.

 

 

 

 

   

  24.May.2012 - schafer@jhu.edu

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