Vol 7, No 6 (2016) > Civil Engineering >

Development of Cold Formed Steel-Timber Composites for Roof Structures: Connection Systems

Ali Awaludin, Anindha Dyah Danastri, Bambang Supriyadi


Abstract: Cold formed
steel has relatively high width-to-thickness ratio elements, which causes it to
buckle easily. Combining it with timber laminas would be an effective solution
for reducing this buckling problem. This research focuses on the connection
system of a cold formed steel-timber composite, which was obtained
by attaching several timber laminas to the web part of cold formed
steel using screws. The connection used two bolts that were 8 mm in diameter,
as well as two different kinds of side plates: steel and plywood. Cold formed
steel 75Z08 and Swietenia mahagoni
(moisture content 12.2%; specific gravity 0.77) were used for connections and
were loaded in parallel and perpendicular directions. In addition, the
connections of cold formed steel (without timber laminas) using
self-drilling screw fasteners were tested until failure. Numerical analysis
predicting the load-slip curve and apparent yield load of the composite joints was
carried out using the DOWEL program and the European Yield Theory,
respectively. The test results showed that the connection system with steel
side plates is capable of accommodating the strength increase of composite
member, as it has a maximum load carrying capacity and initial slip modulus of
about 4.5 and 2 times larger than those of the cold formed steel connections, respectively. In the case
of a connection system with plywood side plates, its joint properties are
similar to those of the cold formed steel connection, except that it has larger
joint deformation.
Keywords: Bolted connections; Cold formed steel; Composite; Load carrying capacity; Timber laminas

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American Forest & Paper Association (AF&PA), 1999. General Dowel Equation for Calculating Lateral Connection Value. Technical Report 12, American Wood Council, Washington, D.C., USA

American Society for Testing and Materials (ASTM), 2002. Standard Test Method for Evaluating Dowel-bearing Strength of Wood and Wood-based Product. ASTM Standard D 5764-97a. Annual Book of ASTM Standard Volume 4.10, ASTM International, West Conshohocken, USA

American Society for Testing and Materials (ASTM), 2003. Standard Test Method for Determining Bending Yield Moment of Nails. ASTM Standard F 1575-03, ASTM International, West Conshohocken, USA

Awaludin, A., Hirai, T., Hayashikawa, T., 2008. Load-carrying Capacity of Steel-to-timber Joints with a Pretensioned Bolt. Journal of Wood Research Science, Volume 54(5), pp. 362-368

Blass, H.J., Bienhaus, A., Kramer, V., 2000. Effective Bending Capacity of Dowel-type Fastener. In: Proceedings of the 33rd CIB-W18, August 2000, Delft, The Netherlands

Brokenbrough, R.L., Merritt, F.S., 1999. Structural Steel Designer’s Handbook, 3rd ed., McGraw-Hill, New York, New York, USA

Chung, K.F., Lawson, R.M., 2000. Structural Performance of Shear Resisting Connection between Cold-formed Steel using Web Cleats of Cold-formed Steel Strip. Engineering Structures, Volume 22(10), pp. 1350-1366

International Organization of Standardization, 1983. Timber Structures – Joints Made with Mechanical Fasteners: General Principles for the Determination of Strength and Deformation Characteristics. ISO 6891-1983. Switzerland

Kwon, Y.B., Chung, H.S., Kim, G.D., 2006. Experiments of Cold-formed Steel Connections and Portal Frames. Journal of Structural Engineering, Volume 132, Special Issue: Cold-Formed Steel Members and Structures, pp. 600-607

Li, X., 2005. Composite Beams of Cold-formed Steel Sections and Wood Members. Thesis, The University of New Brunswick, Canada

Schreyer, A.C., 2002. Monotonic and Cyclic Behavior of Slender Dowel-type Fasteners in Wood-steel-wood Connections, M.A.Sc. Thesis, University of British Columbia, Canada

Smith, I., Asiz, A., Snow, M., Chui, Y.H., 2006. Possible Canadian/ISO Approach to Deriving Design Values from Test Data. International Council for Research and Innovation in Building and Construction, Working Commission W18-Timber Structures, In: 39th Meeting, 28th – 31st August, Italy

Wallace, J.A., Schuster, R.M., LaBoube, R.A., 2001. Testing of Bolted Cold-formed Steel Connections in Bearing (with and without Washer). Final Report, Canadian Cold-formed Steel Research, University of Waterloo, Canada

Winter, W., Tavoussi, K., Pixner, T., Parada, F.R., 2012. Timber-steel-hybrid Beams for Multi-storey Buildings. In: Proceedings of the World Conference on Timber Engineering (WCTE), Auckland, 16-19 July 2012, Session 47, Future Trends 1, pp.41-48