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2013 International Student Competition on Cold-Formed Steel Design

Official Website http://cfscompetition.unt.edu

April 3, 2013

Mission:

The mission of the International Student Competition on Cold-Formed Steel Design (CFS Design Student Competition) is to promote higher education in cold-formed steel structural design and to encourage students to use creative thinking skills to solve engineering problems.

After the successful 2012  and 2011 competition, the 2013 Competition is hosted again at the University of North Teas. We encourage the participation of any students at any level in any major as long as you are creative, interested in designing things, and eager to learn new technologies.

Sponsors:

National Science Foundation,  www.nsf.gov

American Iron and Steel Institute,  www.steel.org

Cold-Formed Steel Engineers Institute, www.cfsei.org

University of North Texas,  www.unt.edu

Eligibility:

The 2013 CFS Design Competition is open to all full-time students at any level. All student entrants are required to work on the problem individually, and no team solutions are accepted.

Competition Organizer:

Dr. Cheng Yu, Associate Professor, University of North Texas.

Judging Panel:

Roger A. LaBoube, Ph.D., P.E., Distinguished Teaching Professor, Missouri University of Science and Technology, US.

Rick Haws, P.E., NBS Group Services, A Nucor Company.

Yuanqi Li, Ph.D., Professor, Tongji University, China.

Yared Shifferaw Bayleyegn, Ph.D., Assistant Professor, Drexel University, US.

Cheng Yu, Ph.D., Associate Professor, University of North Texas, US.

Schedule:

September 15, 2013     Submission deadline. All submissions shall be received electrically before 6:00 pm at student entrant's local time.

November  2013   Winners selected by the Judging Panel.

December 2013    Winners announced.

January 2014       Awards mailed to the winning students.

Awards:

1st place student will receive a $700 USD monetary award.

2nd place student will receive a $350 USD monetary award.

3rd place student will received a $200 USD monetary award.

Each of the top 3 winning students will receive an Award Plaque.

Each of the top 10 winning students will receive a one-year CFSEI student membership.

The winning designs will be recognized and exhibited at appropriate platforms such as professional conferences, websites and news letters.

The 2013 CFS Design Competition Problem:

Task

To design an open section shape for an 8-inch (304.8-mm) deep, 25-ft (7.62-m) long flexural member which provides an adequate nominal bending strength and utilizes the least possible material.

Figure 1

Requirements

1. The section shall have at least one bottom flange and one top flange with a minimum 1.5-inch (38.1-mm) width to accommodate screw-fastened sheathing attachments. The flanges shall be parallel to the X-X axis as illustrated in Figure 1.

2. The cross-section shall be an open shape. Sharp corners (zero radius) can be assumed.

3. The distance between the center lines of the top and bottom flanges shall be 8 inches (203.2 mm).

4. The section should provide a minimum 100 kip-in. (11.30 kN-m) nominal flexural strength against positive bending (top flange in compression). The section should also have a minimum 12 in.^4  moment of inertia of the gross section about the X-X axis (horizontal axis passing centroid).

5. The member shall have uniform thickness, and the steel properties are defined as: Elastic modulus E=29500 ksi (203.4 GPa), Possion's ratio v=0.3, materials yield stress F_y=50 ksi (344.7 MPa). The steel thickness shall be picked from the Table 1.

Table 1

Allowable Steel Thickness

0.0188 in. (0.4775 mm)

0.0283 in. (0.7188 mm)

0.0312 in. (0.7925 mm)

0.0346 in. (0.8788 mm)

0.0451 in. (1.1455 mm)

0.0566 in. (1.4376 mm)

0.0713 in. (1.8110 mm)

0.1017 in. (2.5832 mm)

0.1242 in. (3.1547 mm)

6. It is assumed that the sheathing attachments provide enough restraints against the distortional and the lateral-torsional buckling failures. Only local buckling needs to be checked in the design (assume Mne=My, the nominal flexural strength equals the gross section's yield moment ). The critical elastic local buckling load is defined as the minimum buckling load in the "constrained local buckling domain" at a half-wave length less than or equal to 8 inches.

7. The Direct Strength Method is recommended for calculating the nominal flexural strength (AISI S100 Appendix 1).

Tool

Use an open source software CUFSM to perform the elastic buckling analysis to determine the critical elastic buckling loads. CUFSM 3.12 can be downloaded here. More information about the software can be found in this link.

The Direct Strength Method provisions can be found in the Appendix 1 of the AISI S100-07 North American Specification for Cold-Formed Steel Structural Members.  AISI permits the students to download the AISI S100-07 Appendix 1 for use in this competition only, link.

A detailed design example is provided here, the Direct Strength Method procedure can be found in this document.

Design Package and Submission Info

The design package (zipped in one file) must be submitted via email to CFS_Competition@unt.edu by 6:00pm on September 15, 2013, at student' local time.

The design package shall include three documents:

1) Completed the Information Form. The form can be downloaded here.

2) A design essay (in Word or PDF).

3) The CUFSM result file  ( .mat file).

The design package (3 documents) shall be zipped to one single .zip or .rar file, and then emailed to the above address. The name of the single file shall be in the format: first name_last name.zip or first name_last name.rar.

Requirement for Design Essay

A brief essay (in English), limited to maximum 5 letter-size pages, is required as part of the design package. The essay shall describe the concept of the design, the methodology used for optimization, and the detailed calculation of the nominal compression strength.

Evaluation Criteria:

1. The results of cross-section area (least weight) shall be rounded to 3 significant figures.

2. A valid design with smaller cross-section area (least weight) will be ranked higher.

3. For designs with the same cross-section area (least weight), the one with greater constructability will be ranked higher.

Q and A:

1. The CUFSM only takes two decimals for coordinate inputs but my design has many small elements which need at least four decimals for the node coordinates.

Solution: Use '1/100 inch' as the length unit so that you can adopt more decimals for the coordinates. Here is an example.

What is Cold-Formed Steel?

Cold-formed steel - Wikipedia. http://en.wikipedia.org/wiki/Cold_formed_steel

CCFSS Cold-Formed Steel for Students. http://www.ccfssonline.org/Student/Student.html

For More Information:

Additional questions on the competition subject, CUFSM software, and submissions should be addressed to:

         Cheng Yu, Associate Professor

         University of North Texas

         3940 E. Elm St., Suite F115

         Denton, TX 76207

         Tel: 940.565.2022

         Fax: 940.565.2666

         e-mail: Cheng.Yu@unt.edu

Acknowledgment:

The Competition organizer would like to thank the Sponsors for their financial supports. The Competition is partially funded by the National Science Foundation through a CAREER award (NSF CMMI #0955189). The momentary awards for 2013 Competition are provided by the American Iron and Steel Institute.  The one-year CFSEI student memberships for the top 10 students are provided by the  Cold-Formed Steel Engineers Institute. Any opinions, findings, and conclusions or recommendations expressed in this Competition do not necessarily reflect the views of the sponsors.

The 2013 competition problem was designed by the Judging Panel, their technical advises to this event is greatly appreciated. Special thanks go to Dr. Ben Schafer at the Johns Hopkins University who provided the CUFSM software for this event.

The Competition could not be successful without the promotion and support by the following organizations:

     American Iron and Steel Institute, Education Committee,

     American Society of Civil Engineers, Cold-Formed Member Committee,

     Structural Stability Research Council, Thin-Walled Structures Task Group.

Last updated 04/03/13