PSI - Issue 83

Teresa Morgado et al. / Procedia Structural Integrity 83 (2026) 286–294

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1. Introduction This research aims to study the structural integrity of Ti-6Al-4V produced by additive manufacturing (AM) using the finite elements method (FEM). The research methodology proposed in this work (Figure 1) consists of validating the FEM analysis of Ti-6Al-4V produced by AM using numerical results and existing experimental data from literature. The proposed methodology is fundamental because it will enable the conduct of studies to predict the structural integrity of a metallic alloy component obtained by AM. In developing this work, the implementation of loading conditions in ANSYS was investigated, both with and without contact, while accounting for the AM manufacturing directions and the specific characteristics of the Ti-6Al-4V alloy. The simulations were developed into three-dimensional (3D) models. Studies without fatigue were conducted on cracks ranging from 1.5 mm to 11.64 mm, and fatigue simulations were performed to assess crack propagation. From these studies, it is concluded that 3D finite elements in ANSYS, contact interactions should be used in the simulation of three-point bending tests. 3D fatigue simulations yielded results with higher error percentages (above 10%), attributed to the alignment of crack propagation with the additive manufacturing layer build direction.

Fig. 1. Research Methodology.

2. Theoretical Fundamentals The contour integral method represents one of the most powerful techniques in complex analysis, with engineering applications. This method is based on the residue theorem, a pillar of complex analysis that provides a systematic way to evaluate complex integrals and solve difficult real-valued integral problems (Shehu N. G. et al., 2025). The stress intensity factor (SIF) is a fundamental parameter in linear elastic fracture mechanics (LEFM) that characterises the severity of the crack-tip stress field. SIF represents the local crack-tip stress field singularity and is essentially used to predict crack growth behaviour and assess structural integrity (Anderson, 1990; Anderson, 2017). In finite element analysis, SIF is calculated directly from stress distributions near the crack tip using the contour integral approach, which provides accurate evaluations across multiple integration paths (Morgado and Dias, 2023). The contour integral method enables the extraction of SIF values along various cyclic nodal paths surrounding the crack tip (Bentahar et al., 2024). Equation 1 represents the stress state on the crack tip in polar coordinates (Campbell, 2012). Where ௜௝ is the stress tensor, r is the distance between the crack tip and the stress local, is the angle between