Mechanical behaviour of pre-stressed spruce timber–timber 2.5-mm-step grooved connections under shearing tests

Abstract

A smart shear connection system was tested in order to be used in manufactured elements of a lattice of wooden slats and a cross offset. This type of floor element can present advantages both in terms of weight and suitable insulating filler (Adalberth et al. 2001; Kawasaki and Kawai 2006; Kermani and Hairstans 2006; Dodoo et al. 2014). This connection is made to provide a substitute for a glue connection. The shear connection proposed is made by double-sided grooving timber interfaces to form a cross section. A specifically designed test assembly was constructed to measure and guarantee homogeneous contact pressure in interface test specimens. Shear test results are presented and compared in terms of capacity and stiffness with glue connections. The principal conclusions are as follows: the allowable shearing resistance of the grooved timber-timber joints can approximately reach the resistance of glued connections. The stiffness of the joints is improved by increasing the pre-stress applied for holding contact in the assembly. The grooved timber-to-timber joints exhibit non-linear behaviour which dominates the behaviour of the whole system. Therefore, the behaviour of a unit connection must be determined to obtain the mean load-carrying capacity and stiffness of a system with grooved connections.

A Calculation Method for Interconnected Timber Elements Using Wood-Wood Connections

“…Concerning wood-wood connections, the mechanical behavior of welding-through wood dowels, which is a specific assembly type used in multi-layer spruce beams, was investigated with 2D FE models [40][41][42], as well as a complex 3D FE model [43], with the FE code Cast3M R (CEA, Paris-Saclay, France). The development of these 2D FE models was expanded for grooving timber interfaces by Girardon et al [44,45]. Roche et al [46] studied the semi-rigidity of the dovetail joint for a beam on two supports with a numerical model developed with MATLAB R (The MathWorks Inc., Natick, USA).…”