Strain Distribution of Dowel-Type Connections Reinforced with Self-Tapping Screws
This article has been corrected.
VIEW CORRECTIONPublication: Journal of Materials in Civil Engineering
Volume 32, Issue 1
Abstract
Current limited guidance on the selection of screws together with undefined design specifications restricts the effectiveness of self-tapping screws as reinforcement on timber members to control crack propagation. Using digital image correlation (DIC), this study visualized the surface strain distribution of screw-reinforced dowel-type connections to understand the influence of thread configuration and screw-to-dowel distance on controlling crack propagation. The experiment was based on single-dowel embedment tests using 16- and 20-mm-diameter steel dowels. Three thread lengths (0%, 33%, and 100% thread) and six screw-to-dowel distances (, , , , , and ) were investigated. Results show that a screw with 33% thread on the point end can be as effective as screws with 100% thread to control crack propagation under the same geometrical parameters of the connections. Results also reveal that a screw placed further from the dowel (e.g., at distance) can delay the crack-controlling effect. Self-tapping screws placed at can still improve the embedment strength and ductility; however, further doubling this distance () did not enhance the embedment strength, but a higher ductility was still achieved.
Get full access to this article
View all available purchase options and get full access to this article.
References
Bejtka, I., and H. Blaß. 2005. “Self-tapping screws as reinforcements in connections with dowel-type fasteners.” In Proc., Int. Council for Research and Innovation in Building and Construction-Working Commission W18-Timber Structure (CIB-W18). Karlsruhe, Germany: Universität Karlsruhe.
Blaß, H. J., and P. Schädle. 2011. “Ductility aspects of reinforced and non-reinforced timber joints.” Eng. Struct. 33 (11): 3018–3026. https://doi.org/10.1016/j.engstruct.2011.02.001.
Blaß, H. J., and M. Schmid. 2001. “Self-tapping screws as reinforcement perpendicular to the grain in timber connections.” In Proc., RILEM Symp.: Joints in Timber Structures, 163–172. Paris: Réunion Internationale des Laboratoires et Experts des Matériaux, systèmes de construction et ouvrages.
CEN (European Committee for Standardization). 2001. Timber structures. Test methods. Cyclic testing of joints made with mechanical fasteners. EN 12512:2001. Brussels, Belgium: CEN.
CEN (European Committee for Standardization). 2004. Eurocode 5: Design of timber structures—Part 1-1: General—Common rules and rules for buildings. EN 1995-1-1:2004. Brussels, Belgium: CEN.
CEN (European Committee for Standardization). 2007. Timber structures. Test methods. Determination of embedment strength and foundation values for dowel type fasteners. EN 383:2007. Brussels, Belgium: CEN.
CEN (European Committee for Standardization). 2016. Structural timber—Strength classes. EN 338. Brussels, Belgium: CEN.
Dietsch, P., and R. Brandner. 2015. “Self-tapping screws and threaded rods as reinforcement for structural timber elements—A state-of-the-art report.” Constr. Build. Mater. 97 (Oct): 78–89. https://doi.org/10.1016/j.conbuildmat.2015.04.028.
Foust, B. E., J. R. Lesniak, and R. E. Rowlands. 2014. “Stress analysis of a pinned wood joint by grey-field photoelasticity.” Composites Part B 61 (May): 291–299. https://doi.org/10.1016/j.compositesb.2014.01.041.
Karagiannis, V., C. Malaga-Chuquitaype, and A. Y. Elghazouli. 2016. “Modified foundation modelling of dowel embedment in glulam connections.” Constr. Build. Mater. 102 (Jan): 1168–1179. https://doi.org/10.1016/j.conbuildmat.2015.09.021.
Kunecky, J., V. Sebera, H. Hasnikova, A. Arciszewska-Kedzior, J. Tippner, and M. Kloiber. 2015. “Experimental assessment of a full-scale lap scarf timber joint accompanied by a finite element analysis and digital image correlation.” Constr. Build. Mater. 76 (Feb): 24–33. https://doi.org/10.1016/j.conbuildmat.2014.11.034.
Lathuilliere, D., L. Bleron, T. Descamps, and J. F. Bocquet. 2015. “Reinforcement of dowel type connections.” Constr. Build. Mater. 97 (Oct): 48–54. https://doi.org/10.1016/j.conbuildmat.2015.05.088.
Lionello, G., and L. Cristofolini. 2014. “A practical approach to optimizing the preparation of speckle patterns for digital-image correlation.” Meas. Sci. Technol. 25 (10): 107001. https://doi.org/10.1088/0957-0233/25/10/107001.
Lukacevic, M., J. Fussl, M. Griessner, and J. Eberhardsteiner. 2014. “Performance assessment of a numerical simulation tool for wooden boards with knots by means of full-field deformation measurements.” Strain 50 (4): 301–317. https://doi.org/10.1111/str.12093.
Mastschuch, R. 2000. “Reinforced multiple bolt timber connections.” Master thesis, Dept. of Civil Engineering, Univ. of British Columbia.
Milch, J., J. Tippner, M. Brabec, V. Sebera, J. Kunecky, M. Kloiber, and H. Hasnikova. 2017. “Experimental testing and theoretical prediction of traditional dowel-type connections in tension parallel to grain.” Eng. Struct. 152 (Dec): 180–187. https://doi.org/10.1016/j.engstruct.2017.08.067.
Mohammad, M., A. Salenikovich, and P. Quenneville. 2006. “Investigations on the effectiveness of self-tapping screws in reinforcing bolted timber connections.” In Proc., World Conf. on Timber Construction, 6–10. Corvallis, OR: Oregon State Univ. Conference Services.
Oscarsson, J., A. Olsson, and B. Enquist. 2012. “Strain fields around knots in Norway spruce specimens exposed to tensile forces.” Wood Sci. Technol. 46 (4): 593–610. https://doi.org/10.1007/s00226-011-0429-8.
Reynolds, T., B. Sharma, K. Harries, and M. Ramage. 2016. “Dowelled structural connections in laminated bamboo and timber.” Composites Part B 90 (Apr): 232–240. https://doi.org/10.1016/j.compositesb.2015.11.045.
Salmanpour, A., and N. Mojsilovic. 2013. “Application of digital image correlation for strain measurements of large masonry walls.” In Proc., 5th Asia Pacific Congress on Computational Mechanics, Association for Computational Mechanics, 11–14. Singapore: Association for Computational Mechanics.
Schweigler, M., T. K. Bader, G. Hochreiner, G. Unger, and J. Eberhardsteiner. 2016. “Load-to-grain angle dependence of the embedment behavior of dowel-type fasteners in laminated veneer lumber.” Constr. Build. Mater. 126 (Nov): 1020–1033. https://doi.org/10.1016/j.conbuildmat.2016.09.051.
Sjodin, J., E. Serrano, and B. Enquist. 2006. “Contact-free measurements and numerical analyses of the strain distribution in the joint area of steel-to-timber dowel joints.” Holz Als Roh-Und Werkstoff 64 (6): 497–506. https://doi.org/10.1007/s00107-006-0112-1.
Sutton, M. A., J. J. Orteu, and H. W. Schreier. 2009. Image correlation for shape, motion and deformation measurements: Basic concepts, theory and applications. New York: Springer.
Thelandersson, S., and H. J. Larsen. 2003. Timber engineering. New York: Wiley.
Uibel, T., and H. Blaß. 2010. “A new method to determine suitable spacings and distances for self-tapping screws.” In Proc., Int. Council for Research and Innovation in Building and Construction-Working Commission W18-Timber Structure (CIB-W18). Karlsruhe, Germany: Karlsruhe Institute of Technology.
Zhang, C., W. Chang, and R. Harris. 2015. “Investigation of thread configuration for self-tapping screws as reinforcement for embedment strength.” In Proc., Int. Network on Timber Engineering Research, 449–451. Zagreb, Croatia: Univ. of Zagreb.
Zhang, C., W. Chang, and R. Harris. 2016. “Investigation of thread configuration of self-tapping screws as reinforcement for dowel-type connection.” In Proc., World Conf. on Timber Engineering 2016, 1440–1448. Vienna, Austria: Univ. of Vienna.
Zhang, C., W. Chang, and R. Harris. 2018. “Screw reinforcement on beam-to-column dowel-type connection.” In Proc., World Conf. on Timber Engineering 2018. Seoul: World Conference on Timber Engineering.
Zhang, C., H. Guo, K. Jung, R. Harris, and W. Chang. 2019a. “Screw reinforcement on dowel-type moment-resisting connections with cracks.” Constr. Build. Mater. 215 (Aug): 59–72. https://doi.org/10.1016/j.conbuildmat.2019.04.160.
Zhang, C., K. Jung, H. Guo, R. Harris, and W. Chang. 2019b. “Using self-tapping screw to reinforce dowel-type connection in a timber portal frame.” Eng. Struct. 178 (Jan): 656–664. https://doi.org/10.1016/j.engstruct.2018.10.066.
Zhang, C., K. Jung, R. Harris, and W.-S. Chang. 2019c. “Drive-in torque for self-tapping screws into timber.” Proc. Inst. Civ. Eng. Constr. Mater. https://doi.org/10.1680/jcoma.18.00087.
Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 32 • Issue 1 • January 2020
Copyright
©2019 American Society of Civil Engineers.
History
Received: Nov 1, 2018
Accepted: Apr 23, 2019
Published online: Oct 23, 2019
Published in print: Jan 1, 2020
Discussion open until: Mar 23, 2020
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.