Authors:
Galina E.Okolnikova,Arslan K. Kurbanmagomedov,Andrew S. Korzin,DOI NO:
https://doi.org/10.26782/jmcms.spl.9/2020.05.00010Keywords:
Nailed connection,wood,load bearing capacity,deformability,experiment planning,fiberglass bushing,Abstract
This study is devoted to one of the most common types of wooden structural elements joints - nailed connections. The article presents the results of experimental studies of two types nailed connections on metal plates: traditional connections without bushings and connections, reinforced (modified) with pressed-in fiberglass bushings. The methods of mathematical planning of the experiment were used during the test. That allowed to significantly reduce the number of tested samples of connections and to obtain mathematical dependences in the form of response functions for such characteristics as breaking load Nt and load NI-II, corresponding to the upper boundary of the elastic behavior area of the compound from three factors: the angle between the direction of the acting force and the direction of the wood fibers, the dowel diameter and the wall thickness of the fiberglass bushing. The obtained dependences allow us to evaluate the values of the loads Nt and NI-II for the nailed connections with bushings without testing.According to the experiment planning matrix, 15 types (series) of connections with pressed-in fiberglass bushings and 9 types (series) of traditional nailed connections without bushings were tested.According to the test results, the authors made a comparison of the load bearing capacity and deformability of two types of nailed connections, with bushings and without bushings; the nature of the damage has been established; the analysis of stress-strain state of the middle wooden element in the area of mortise strengthened with pressed-in fiberglass bushing is performed; the conclusion about prospects of application of a pressed-in fiberglass bushings to enhance mortises of new structures and when reconstructing wooden structures in operation.Refference:
I. A. Hassanieh, H. R. Valipour, M. A. Bradford. Experimental and analytical behaviour of steel-timber composite connections. Construction and Building Materials, Volume 118, 15 August 2016, Pages 63-75
II. Danielsson, H., Gustafsson, P. Fracture analysis of perpendicular to grain loaded dowel-type connections using a 3D cohesive zone model. Wood Material Science and Engineering Volume 11, Part 5, 2016, pp. 261-273.
III. E-M.MeghlataM.OudjenebH.Ait-AideraJ-L.Batozc. A new approach to model nailed and screwed timber joints using the finite element method. Construction and Building Materials, Volume 41, April 2013, Pages 263-269
IV. Gianni Schiro, Ivan Giongo, Wendel Sebastian, Daniele Riccadonna, Maurizio Piazza. Testing of timber-to-timber screw-connections in hybrid configurations. Construction and Building Materials, Volume 171, 20 May 2018, Pages 170-186.
V. Hans Joachim Blaß, Patrick Schädle. Ductility aspects of reinforced and non-reinforced timber joints. Engineering Structures, Volume 33, Issue 11, November 2011, Pages 3018-3026.
VI. Jockwer, R., Serrano, E., Gustafsson, P.-J., Steiger, R. Impact of knots on the fracture propagating along grain in timber beams. International Wood Products Journal 8 (1), 2017, pp. 39-44.
VII. Larsson, G., Gustafsson, P.J., Crocetti, R. Use of a resilient bond line to increase strength of long adhesive lap joints. European Journal of Wood and Wood Products, 2018, pp. 401-411.
VIII. Larsson, G., Gustafsson, P.J., Serrano, E., Crocetti, R. Bond line models of glued wood-to-steel plate joints. Engineering Structures, Volume 121, 2016, pp. 160-169.
IX. MatteoBarbari, Alberto Cavalli, Lorenzo Fiorineschi, Massimo Monti, Marco Togni. Innovative connection in wooden trusses.Construction and Building Materials, Volume 66, 15 September 2014, Pages 654-663
X. NatalinoGattesco, Ingrid Boem. Stress distribution among sheathing-to-frame nails of timber shear walls related to different base connections: Experimental tests and numerical modelling. Construction and Building Materials, Volume 122, 30 September 2016, Pages 149-162
XI. Okolnikova G.E. Analysis of the work of nagelnyh joints of wooden structures from the standpoint of fracture mechanics // Makeyevka: “Bulletin of DonNACEA”. 2011- 4 (90). – pp. 40-46.
XII. Okolnikova G.E. Calculation of nagel compounds modified with pressed fiberglass bushings. – Moscow: MGOU, “Bulletin of MGOU”, No. 1 (3), 2009, pp. 28 – 33.
XIII. Okolnikova G.E. Investigation of the relationship between the fracture toughness of wood and the calculated resistance of wood to stretching along the fibers. Bulletin of MGOU. – Moscow: MGOU, No. 2, 2010, p. 23-26.
XIV. PrimožJelušič, StojanKravanja. Flexural analysis of laminated solid wood beams with different shear connections. Construction and Building Materials Volume 174, 20 June 2018, Pages 456-465.
XV. R. Wang, S.Q. Wei, Z. Li, Y. Xiao. Performance of connection system used in lightweight glubam shear wall. Construction and Building Materials, Volume 206, 2019, Pages 419-431.
XVI. Recommendations for the testing of joints of timber structures / TSNIISK them. V.A. Kucherenko. – Moscow: Stroiizdat, 1980. – 40p.
XVII. SP 64.13330.2011. Timber structures. Updated version of SNiP II-25-80 (with Amendment No. 1). Moscow: Ministry of Regional Development of Russia, 2011. – 92p.
XVIII. Themelina Paraskeva, Nischal P. N. Pradhan, Charikleia D. Stoura, Elias G. Dimitrakopoulos. Monotonic loading testing and characterization of new multi-full-culm bamboo to steel connections. Construction and Building Materials, Volume 201, 20 March 2019, Pages 473-483
XIX. Ulf Arne Girhammara, Nicolas Jacquierb, Bo Källsnerc. Stiffness model for inclined screws in shear-tension mode in timber-to-timber joints. Engineering Structures, Volume 136, 1 April 2017, Pages 580-595.
XX. Ursula Mahlknechta, Reinhard Brandnerb. Block shear failure mechanism of axially-loaded groups of screws. Engineering Structures, Volume 183, 15 March 2019, Pages 220-242.