Issue 44

A. Saoud et alii, Frattura ed Integrità Strutturale, 44 (2018) 25-34; DOI: 10.3221/IGF-ESIS.44.03 31 Crack length a (mm) Critical load (kN) Average load (kN) Standard deviation (kN) a=4 1 0.81 1.14 0.95 0.13 0.98 0.80 a=6 0.882 1 0.90 0.88 0.07 0.85 0.801 a=8 0.57 0.59 0.60 0.59 0.01 0.60 0.57 a=10 0.54 0.54 0.54 0.55 0.01 0.55 0.57 a=12 0.51 0.40 0.47 0.51 0.07 0.54 0.61 Table 3: Evolution of the maximum load for each test. Figure 8: The experimentally defined compliance as a function of the crack length. To perform the calculations, the following assumptions were assumed:  Wood is a homogeneous material because the dimensions of the specimen are large compared to the difference between the diameters of two consecutive rings.  The elastic behavior is valid.  The orthotropic stiffness matrix is known.  The elastic constants used hereinafter, listed in Tab. 4, were determined using the predictive model developed by