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A simplified and reliable tool for the elastic analysis of one-storey timber shear-walls under simultaneous horizontal and vertical loads is presented. This approach is suitable for the analysis both of light timber-frame walls and CLT walls. The analytical expressions to determine the horizontal displacement and the elastic stiffness of a single wall are provided, these expressions are then extended to walls placed in series. A simplified numerical model suitable for F.E. analysis is also developed. In the last part of the paper a comparison between an analytical example and the results of a laboratory test is shown.

The paper presents the outcome of a research on the in-plane behaviour of two different log house construction systems when subjected to lateral loading. Such systems, identified by the way the logs are joined together are: the Standard half lapped joint (ST) system and Tirolerschloss joint (TR) system. Two stages of experimental testing were carried out at the laboratory of the University of Trento. In the first stage the focus was on the corner joints and on a possible wall reinforcement system (22 monotonic and 5 cyclic tests were performed). In the second stage full-scale wall specimens were tested (5 monotonic and 5 cyclic tests). Several layouts were investigated: 4.2 m long walls with thin (TR and ST) or thick logs (ST); “short” walls (2.75 m long); walls with openings. The test results highlighted some critical aspects in the in-plane behaviour of the walls. The lateral load carrying capacity of the wall appeared to be influenced by two main phenomena: friction and corner-joint interlocking. Due to mounting tolerance a large displacement was required to fully engage the corner joint resistance. A large horizontal plateau characterized the post friction part of the load displacement curve (wide plateau) both for ultimate limit state (ULS) and serviceability limit state (SLS). The cyclic tests showed a high level of energy dissipation that was attributed to the “inter-log friction”. In order to have a better insight into such aspects, a simplified rheological/analytical model was developed by using the experimental data as input parameters. A good agreement between the model output and the experimental behaviour was obtained.

The mechanical behaviour of timber frame shear walls subjected to in-plane forces has been investigated through full-scale tests. Eleven monotonic and 11 cyclic tests were performed on full-scale shear walls, each 2·5 m high by 2·5 m long. Some variables were changed during the tests as follows; different vertical loads were applied, various angle brackets and hold-downs were used, and different sheathing panels were connected to the timber frame. Also, the influence of openings was investigated. Furthermore two walls with non-structural finishing were tested in order to correlate the inter-storey drift with the level of damage. In part 1 of the paper, the test procedure and test results are presented. A detailed discussion of the test apparatus and how the boundary conditions influence the results are also reported. The theoretical approach used to predict the mechanical behaviour of the presented system is explained.

The mechanical behaviour of timber frame shear walls subjected to in-plane forces has been investigated through full-scale tests. Eleven monotonic and 11 cyclic tests were performed on full-scale shear walls, each 2·5 m high and 2·5 m long. Different variables were changed during the tests as follows. Different vertical loads were applied, different angle brackets and hold-downs were used and different sheathing panels were connected to the timber frame. Also, the influence of openings was investigated. Furthermore, two walls with non-structural finishing were tested in order to correlate the inter-storey drift with the level of damage. This paper (part 2) reports on a comparison between different test results, permitting evaluation of the influence of each variable on the stiffness and the resistance of the walls. Moreover, the theoretical formulae presented in a companion paper (part 1) were compared with the outcome of the tests, and good agreement was found. The racking resistance predicted by Eurocode 5 was also checked using the data obtained from the tests.

This paper reports on a shaking table test conducted on a timber-framed building sheathed with oriented strand board within the framework of the European Series project at the National Laboratory of Civil Engineering in Lisbon, Portugal. The test structure was a full-scale, three-storey, 7 m × 5 m plan building. The aim of the tests was to assess the integrity of the structural members and the non-structural components during a seismic event. The structural design was carried out in accordance with European standards. The input signals comprised ‘accelerograms’, which were scaled versions of those recorded during the Montenegro (1979) and Tohoku (2011) earthquakes. The outcome of the tests showed excellent seismic behaviour, as demonstrated by the fact that the structure frequency did not change until the last step of the procedure. Moreover, after 17 simulations, no visible damage was detected.

Shake table tests were carried out on a 7 m × 5 m three-story, timber light-frame building (7.5 m height) at the TreesLab laboratory (Eucentre) in Pavia. The aim of the research was to evaluate the seismic behavior of a typical Italian prefabricated timber building and to study the interaction between the individual structural components tested in quasi-static manner in a previous experimental study. The 1979 Montenegro Earthquake ground motion, recorded at the Ulcinj-Hotel Albatros station, was selected as the ground motion for seismic tests. The maximum peak ground acceleration was scaled to 0.07 g, 0.27 g, 0.5 g. 0.7 g, and 1 g in order to evaluate the building’s performance at different levels of seismic input. More than 100 instruments were used to monitor the behavior of the building during seismic tests measuring acceleration, displacement, and forces. The visual inspection shows that the building did not show any damage during all seismic tests. However the data analysis (dynamic identification, c...

For the horizontal stability of timber framed buildings, diaphragm action in the walls is of crucial importance. The structural behaviour and capacity of wall diaphragms are primarily dependent on the sheathing-to-timber connections. Holding down and shear transfer are limiting criteria of importance. Tests on connections between sheathing panel and wood stud were carried out. Different types of sheathing materials and connectors were combined. OSB with different thickness (12 and 15 mm) and gypsum-fibre panel were tested. Nails and staples were used to connect the panels to the wooden studs. Monotonic and cyclic destructive tests were performed on different connections to determine how the different systems behave. Comparison between different standard were carried out.

Light timber structures have always been considered performing well during earthquakes, because of the high ratio between strength and mass. In platform frame constructions the task of resisting to the horizontal forces (wind, earthquake) is entirely left to the shear walls. The mechanical characterization of connections between the wall panels and the foundation and between the wall panels at different storeys is extremely important in order to investigate the global response of multi-storey buildings subjected to lateral loads. To this purpose different types of commercial or ad hoc designed connections system were experimentally investigated by means of monotonic and cyclic tests, in order to derive their stiffness and strength parameters. The experimental results confirmed the good mechanical behaviour of the proposed systems compared to the systems commonly adopted in practice. A simple engineering model is proposed to describe the force transmission mechanism between the connection elements.

This paper concerns the development of innovative composite floor systems, comprising timber beams and prefabricated concrete slabs. For the development of this new system, two properties were regarded as vital, as follows: (1) good stiffness, and (2) a high degree of prefabrication. Shear connection systems installed using completely dry processes were used. Innovative and very efficient materials, such as fiber-reinforced concrete (FRC) and modified wood, were used for the manufacture of the specimens. The research reported in this paper was conducted in two phases, as follows: (1) the mechanical properties of different shear connectors were investigated (Phase A), and (2) on the basis of these experiment's results a second investigation was carried out in order to study the behavior of full-scale timber-concrete composite slabs (Phase B). During Phase A four different configurations, with a total of eight specimens, were laboratory tested in shear. During Phase B two full-scale floor elements, each with a different shear connection system, were laboratory tested in bending. The two shear connector systems used in the investigation were (1) shear anchor-keys of furfurylated wood, and (2) inclined steel tubes. Both of the proposed connection systems performed more than satisfactorily, showing a very high degree of composite action even at load levels close to the failure load. Moreover, it appeared that the assembling of the prefabricated fiber-reinforced concrete slab with the underlying beams occurred in an extremely easy manner. (C) 2014 American Society of Civil Engineers. (Less)

A novel type of timber-concrete composite floor, consisting of longitudinal glulam beams with a fibre reinforced concrete (FRC) slab on the top is proposed. In order to check some relevant mechanical properties of such a floor, full-scale laboratory tests along with numerical analyses were carried out. The shear connector system used in the investigation consisted of self-tapping screws driven at an angle of 45° to the grain direction of the glulam beams. The manufacture of the structure occurred according to the following steps: (a) the screws were inserted on the top of the glulam beams; (b) the beams were rotated 180° about the longitudinal axis and placed in a concrete formwork; (c) the FRC was cast into the formwork; (d) after curing of the FRC, the composite floor was again rotated 180° about the longitudinal axis into its right position, i.e. with the FRC slab on the top side. Long term tests and quasi-static bending tests were performed. It was found that the proposed connection system showed a very high degree of composite action both during the long-term testing and at load levels close to the failure load. Furthermore, the assembly of the prefabricated timber-concrete composite system revealed to be very fast and easy.