Simulating Failure of Ti-6Al-4V Tensile Specimens Fabricated by Electron Beam Powder Bed Fusion Process: Johnson–Cook Model

This study examines the fracture behavior of Ti-6Al-4V dog-bone specimens manufactured using the electron beam powder bed fusion (EB-PBF) additive manufacturing. A combined experimental and numerical approach was adopted to achieve a comprehensive understanding of the material’s tensile response and to validate the predictive capability of a constitutive damage model. Uniaxial tensile tests were first carried out on the fabricated specimens to obtain detailed load–displacement data and characterize their elastic and plastic deformation behavior. The fundamental elastic–plastic properties of the material were extracted from standard tensile test results and used as the basis for subsequent numerical modeling. To capture the material’s damage behavior, the Johnson–Cook (J-C) constitutive and damage models were implemented in a finite element framework. The model parameters were calibrated using an iterative procedure in which the numerically predicted load–displacement curves were systematically compared with the corresponding experimental results. This calibration strategy enabled an accurate representation of both damage initiation and progressive failure under tensile loading conditions. Key mechanical responses, including initial stiffness, yield strength, and peak load, were derived from the experimental data and directly compared with simulation outputs to assess model accuracy. The numerical simulations demonstrated strong agreement with the experimental observations across all stages of deformation. The deviation between predicted and measured responses remained within approximately 5% for the dog-bone specimens, indicating a high level of predictive reliability. Overall, the results confirm that the J-C model provides a robust and effective framework for simulating tensile deformation and fracture behavior in EB-PBF-fabricated Ti-6Al-4V components, supporting its use in the mechanical design and assessment of additively manufactured metallic structures.