Issue 39

A. Lokaj et alii, Frattura ed Integrità Strutturale, 39 (2017) 56-61; DOI: 10.3221/IGF-ESIS.39.07 60 From the course of deformation of the round timber joints and squared timber joints it is evident that resistance and stiffness at different angles reaches comparable values. Only squared timber joints samples exposed to force parallel to the grain exhibit less deformation than the corresponding round timber joints. Connections with squared timber also have significant plastic deformations prior to the collapse of the joints, in contrast to round timber joints. Different behaviours during testing at different angles of the loading force to the grain are shown in Fig. 3 and 4. Summary of the test results of round timber and squared timber samples subjected loading force at different angles to the grain are shown in Tab.2. Samples type Value Loading force orientation at an angle to the grain 0° 60° 90° ̅ݔ SD CV ̅ݔ SD CV ̅ݔ SD CV Round timber Density (kg  m -3 ) 412.6 42.1 10.2 405.9 26.4 6.5 414.9 46.2 11.1 Capacity from test (kN) 64.9 6.3 9.7 41.7 4.8 11.5 40.6 5.0 12.5 EC5 (kN) 38.7 30.8 28.5 Squared timber Density (kg  m -3 ) 426.8 13.77 3.2 443.6 14.6 3.3 454.4 50.1 11.0 Capacity from test (kN) 57.7 5.1 8.8 49.7 2.9 5.8 32.5 3.6 11.1 EC5 (kN) 39.3 32.8 31.4 Table 2 : Summary of the carrying capacity test results and the calculated values of load carrying capacity according to EC5 ( x is the arithmetical average; SD is the standard deviation; CV is the coefficient of variation). Figure 5 : Damaged round timber samples loaded in tension at different angles. Figure 6 : Damaged squared timber samples loaded in tension at different angles.