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Highlights • The maximum forces from calculations based on Eurocode 5 are higher than forces from experiments. • The calculation models correlate well with experiments. • The standard EN 26891 is not convenient for joints with brackets. Abstract The aim of this study is to describe the design of steel angle bracket in timber joints. The design has insufficient support in the existing standards. The load-bearing capacity of these connections can be calculated in accordance with EN 1995-1-1 Eurocode 5, Chapter 8 Connections with metallic fasteners. The main drawback is that this manual only focuses on the metallic fasteners itself. The other disadvantage is that it does not look into the question of stiffness of the joint, its deformation, which is often a problem with these connections. This issue was confirmed by experiments in this study. Eight different angle brackets have been tested in the load direction where the part of the metallic fasteners is stressed in the pull and the second part in the shear. In addition, three different angle brackets were tested in the load direction where all the metallic fasteners are stressed in shear. These experiments were compared with computational models and the calculations according to EC 5. The computational models were performed in software RFEM5. The angle brackets were modeled, nails and wood were replaced by point or flat supports. The results from computational models are comparable to experiments. However, the values given by the calculations according to EC 5 are considerably higher than the real load-bearing capacities obtained from the experiments. Therefore the use of EC 5 for this type of connections can be dangerous in practice. The differences between experiments, models and calculations indicate the difficulty of designing timber joints with three-dimensional nailing plates. [ABSTRACT FROM AUTHOR]

The research deals with a 49.0mm in diameter mechanical fastener to which load perpendicular to grain is applied. The experimental research was divided in two series: the first series was carried out with locally reinforced, and the second with non-reinforced timber specimens. The local reinforcement of timber elements with textile sheets between lamellas in a layer of adhesive was made in the production process. Furthermore, research on finite element models using Abaqus/CEA software package was carried out. UMAT subroutine and cohesive contact between surfaces were used for modelling complex timber mechanical properties and cracks opening. The research results have shown that glass fiber textile placed between lamellas in adhesive layer effectively increases the resistance and splitting capacity of timber joint. Analytical approach has been proposed for predicting the splitting capacity of the reinforced joint. [ABSTRACT FROM AUTHOR]

The article discusses the main methods for steel threaded rods pasted into timber. Single -- threaded steel rod carrying capacity glued onto glulam (timber cross section -- 100 x 100 mm, threaded rod -- M12 and M16) has been experimentally determined. Behaviour based on the experimental results of two different methods for pasting rods into timber has been summarized: the first threaded steel rod was glued into 4 mm bigger diameter hole while the second -- rod chased into 2 mm smaller diameter hole. The conducted experiment used 800 mm length glulam beams; threaded steel rods were glued to both ends of specimens (equal theoretical carrying capacity). The experiment in the tension of both ends was carried out. The obtained results were compared with theoretical expressions submitted in EC 5 -- 1 -- 1:2005 and STR 2.05.07:2005. The main dependences of geometrical parameters and carrying capacity have been provided. The main collapse forms of specimens and manufacturing defects having influence on the final carrying capacity and behaviour of the joint have been observed. Using the first method, a failure in the pasted rod occurs suddenly when timber splits along the fibre; in the second case, a failure is plastic when timber is compressed under thread. Additional experiments must be carried out using the first technology increasing the class of the strength of the pasted rod as under the maximum length of paste, in all cases, failure in the pasted rod occurred when a steel bar cracked. Along with an increase in the diameter of the rod, the dispersion of the results of the affixed slender part is increasing. Maximum variation in the results of applying the first method is 10%, whereas the second method of attaching makes 50%. Compared to the first method of attaching, the results of theoretical bearing capacity indicate that tests have an adequate margin which is equal to or is more than 2,0. A comparison of the second method of attaching results to theoretical bearing capacity makes clear that the experimental results of the tests have too low safety factor and in some cases are less than 1.0. This is due to the fact that the counting of attaching technology in some cases must be based on local compressed timber strength. The experimental study of two different methods for attaching steel bars reveals that the first method can be used in design practice considering both documents STR 2.05.07:2005 and EC 5-1-1:2005. The second method of attaching must be developed to ensure smooth rod surface coating adhesive. Attaching the second method should also be created in the exact form corresponding to the disintegration of the calculation model. [ABSTRACT FROM AUTHOR]