Issue 53

R. Harbaoui et alii, Frattura ed Integrità Strutturale, 53 (2020) 295-305; DOI: 10.3221/IGF-ESIS.53.23 299 Figure 1: Hardening Curves of uniaxial tensile [17] . Figure 2: hardening curves of uniaxial compression [17]. Ψ (°) Lankford coefficients 0 1.47 45 2.77 90 3.89 Table 3: Experimental Lankford coefficients. Numerical results: Identification of the hardening parameters For the identification procedure, we will use the CPB06 model [9] while respecting the assumptions cited above. This step consists of choosing the coefficients of the model while minimizing the squared difference between the theoretical and experimental results. The hardening function σ s ( α ) is identified from the tensile hardening curves in the TD and RD directions for the tensile test (Figure 1) and of the experimental compression test (Figure 2) in the ND direction. In this case, four handening laws are used: Hollomon's law, Voce's law, Swift's law and Ludwick's law to best describe the function σ s ( α ) (9)-(12). The experimental results found are the first and only source of data for the implementation of this identification strategy. The identification results are shown in Tables 4 and 5. Table4, table 5 and table 6 present the identified parameters of the hardening laws for tensile tests in rolling direction, in transverse direction and for compression test in normal direction, respectively.