Issue 53

R. Harbaoui et alii, Frattura ed Integrità Strutturale, 53 (2020) 295-305; DOI: 10.3221/IGF-ESIS.53.23 300 Hollomon Swift Ludwick Voce Err 0.0205 Err 0.0116 Err 0.0124 Err 0.0372 K 402.605 K 447.0761 σ 0 150.6813 σ y 1440.8 n 0.1496 ε 0 0.0116 K 337.5205 α 0.9 n 0.2015 n 0.3925 β -0.7 Table 4: Identified parameters of the hardening laws for the tensile test (RD). Hollomon Swift Ludwick Voce Err 0.0123 Err 0.0118 Err 0.0118 Err 0.0517 K 439.1366 K 445.9781 σ 0 51.4125 σ y 610.305 n 0.1621 ε 0 0.0013 K 401.2347 α 0.662 n 0.1693 n 0.2032 β -2.8943 Table 5: Identified parameters of the hardening laws for the tensile test (TD). Hollomon Swift Ludwick Voce Err 0.0194 Err 0.0076 Err 0.0167 Err 0.038 K 540.4411 K 490.1859 σ 0 -422.981 σ y 502.9209 n 0.1427 ε 0 -0.0099 K 940.3702 α 0.4453 n 0.0995 n 0.064 β -7.1496 Table 6: Identified parameters of the hardening laws for the compression test (ND). Identification of the hardening curves : In Figure 3,4 and 5, the experimental hardening curves (EXP) and the identified curves using the four hardening laws are represented for three tests. The identification consists of finding the hardening function σ s ( α ), applying the least squares fitting between the theoretical and the experimental results using the simplex algorithm. Thereafter, a comparison between the four hardening laws will be carried out in order to show the most appropriate law for the identification of tensile and compressive hardening curves in plastic deformation. Figure 3: Identification of the tensile curve for RD with different hardening laws