Mixed mode fracture of glued-in rods in timber structures

Experimental Investigation of Mode-I Fracture Properties of Parallel Strand Bamboo Composite

“…Hence an R-curve cannot be considered as an intrinsic fracture characteristic of a material (Lartigau et al 2015). Indeed, the small crack always becomes located in the cantilever or in the main crack-front after the main crack growth; thus the compliance evaluated by linear FEM model may significantly derivate from the real value.…”

Joints with bars glued-in softwood laminated timber subjected to climatic cycles

“…The explanation of this phenomenon could come from the difference in the distribution of shear stresses along the joint according to its slenderness. The existing studies indicate that in reduced anchorage lengths, the stresses along the joint are quite even, and as long as the length increases, more stress peaks are produced at the ends of the joints [7,21,36,48]. In longer joints, those highest stress peaks are located on the exterior end of the joint, which coincides with the adhesive area that is the most exposed to climatic conditions, since, as we have seen, on the inner area of the joint, wood behaves as a retardant barrier for heat.…”

“…Literature agrees that the gluing area defines the resistance of the joint but there is still no final agreement regarding the quantification of that influence [2,19]. This becomes clear in the lack of a common European legislation that includes a clear regulation about the use and dimensioning of this kind of joints, in spite of the fact that numerous dimensioning formulas of experimental [2,15,16,18] or analytical basis [7,[20][21][22] have been postulated. Although since the 90s several proposals of design rules for implementation in EC5 have been made, only a few European countries have a calculation model in their national standards, highlighting the one proposed by the German DIN rule as the most used design method [1,19].…”

“…Existing studies seem to indicate that joints with glued-in rods subjected to long-term loads, compared to short-term loads, show a reduction of strength of similar magnitude to the one that would affect the wooden elements in the same situation [5,14,30].This is due to the fact that neither the bar nor the adhesive are affected by this factor. On the contrary, very different creep behaviours have been found when comparing different adhesives [21,31]. Verdet et al [31] performed creep tests in a walk-in environmental chamber.…”

Glued-in rods in cross laminated timber – Numerical simulations and parametric studies

“…FE-analysis has also been used in some recent studies dealing with glued-in rods or other related fields of timber engineering, such as nailed and screwed timber joints, hold-down connections, and different types of composite timber connections [15][16][17][18][19][20][21][22]. Some of these studies made use of linear elastic 3D FE-analysis in order to investigate the stress response in the connections, whereas others used more elaborate models, including probabilistic models and CZMs to analyse, for instance, the effect of different rod spacings, as well as that of glue-line thickness, on the pull-out load-bearing capacity.…”