Issue 53

R. Harbaoui et alii, Frattura ed Integrità Strutturale, 53 (2020) 295-305; DOI: 10.3221/IGF-ESIS.53.23 301 Figure 4: Identification of the tensile curve for TD with different hardening laws Figure 5: Identification of the compression curve for ND with different hardening laws The identification is made in the area of plastic deformation where the elastic deformation is neglected (as it is indicated above in the hypothesis). It is clearly seen that the Swift and Voce laws are a little far from identifying AZ31B in uniaxial deformation. Indeed, the Ludwick and Hollomon laws describe the hardening curves better than those of Voce for all the loading directions. On the other hand, Ludwick and Hollomon laws give very similar results for the TD and RD directions for the tensile test compared to the rolling direction especially at the area of the plastic deformation domain. We can therefore conclude that Ludwick's law is sufficient to model the plastic behavior of the magnesium alloy in the two cases of monotonic loading: simple tensile and simple compression. In conclusion, the isotropic hardening Ludwick's law is chosen in continuation of this work to identify the anisotropic behavior of this alloy. Validation : After proving in previous work [9] and [10] that n remains the same for different tests, table 7 and 8 present the identified parameters where n is fixed for ψ =0°. We will therefore choose ‘n’ relating to the tensile test carried out in the rolling direction in addition to that it is the most simple and easy test to perform. By convention, we choose n for tensile test in the rolling direction as a reference. For n = 0.3925, we present different values of K and σ 0 (Table 7). Ludwick00 Ludwick TD Error 0.0124 0.0192 σ 0 150.6813 148.4634 K 337.5205 384.4332 Table 7: Hardening parameters for Ludwick law for fixed n=0.3925