Issue 44

G. Testa et alii, Frattura ed Integrità Strutturale, 44 (2018) 161-172; DOI: 10.3221/IGF-ESIS.44.13 165 f f k p    (13) Other damage parameters, which define the shape of the evolution of different damage contribution with plastic strain, can be determined performing measurement of loss of stiffness as discussed in [19]. In a first approximation,  =0.3 is a suitable value for several classes of materials. More difficult is the determination of  . Barsoum and Faleskog [8] found that at low levels of stress triaxiality, failure seems to be governed by a simple criterion based on a critical measure of plastic shear deformation. Therefore, following the Occam’s razor principle,  =0 is assumed. Figure 3 : H4 C-SKR rivet type. D=5.0 mm, H=5.45 mm, B=7.67 mm. Figure 4 : Self-piercing riveting configuration for FEM analysis. CASE UPPER SHEET LOWER SHEET 1 STEEL (DP600) AL2024 2 STEEL (DP600) OFHC Cu 3 AL2024 AL2024  OFHC Cu STEEL (DP600) Table 1 : Summary of investigated SPR configurations. S ELF - PIERCING RIVETING SIMULATION Geometry he self-piercing riveting process was simulated with FEM using XBDM model. All finite element simulations have been performed with MSC MARC v2017.1. In this FEM code, the BDM is ready available, however the XBDM was implemented using user subroutines. Here, a self-pierce H4 C-SKR rivet was selected to simulate joining of T