Issue 43

B. Saadouki et alii, Frattura ed Integrità Strutturale, 43 (2018) 133-145; DOI: 10.3221/IGF-ESIS.43.10 135 Figure 2 : Schematic illustration of the experimental apparatus.      max min 2 a (1)      max min 2 m (2) And the ratio of extreme stresses (maximum and minimum), also called load ratio and defined by:    min max R (3) where, σ min and σ max are respectively the minimum and maximum stresses to which the specimen is subjected. The tests are conducted with zero-based loading at stress ratio R = 0 (Fig. 3), this implies the following equations:      max 2 m a (4)     max (5) R ESULTS AND ANALYSIS atigue tests of studied material should be preceded by mechanical analysis of his answers to simple solicitation through tensile tests. Starting fatigue tests requires the definition of the first value of the maximum imposed stress. Monotonic tensile behavior Tensile tests have been carried out to characterize the monotonic properties of the material. Tests were conducted until the failure on a Zwick Roell machine under displacement mode. An additional test where an extensometer was used to the gauge length was performed to measure accurately the Young modulus. Monotonic tensile properties values are summarized in Tab. 1. F