PSI - Issue 83

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

290

Table 1. Mechanical Properties of the Ti-6Al-4V used in this research.

Yield Tensile Strength [MPa]

Ultimate Tensile Strength [MPa]

Young Modulus [GPa]

Elongation [%] 11.8 ± 0.5

Planes

XZ (vertical) YZ (vertical)

978 ± 5 967 ± 10 1075 ± 25

1143 ± 6 1117 ± 3 1199 ± 49

115 ± 6 119 ± 7 113 ± 5

8.9 ± 0.4 7.6 ± 0.5

XY (horizontal)

Table 2. Fatigue parameters of the Ti-6Al-4V used in this research.

C [m/cycle]

Δ K [MPam 1/2 ]

Δ K th [MPam 1/2 ] 1143 ± 6 1117 ± 3 6.3 ± 0.7

m

R

Planes

XZ (vertical) YZ (vertical)

36.0 ± 22.69

0.1 0.1 0.1

1.7E-10 ± 5.8E-11 2.1E-10 ± 1.6E-11 1.2E-10 ± 7.6E-11

2.366 ± 0.27 2.451 ± 0.63 2.612 ± 0.25

33.4 ± 3.6 33.3 ± 3.9

XY (horizontal)

The Poisson’s ratio used in the analysis was  = 0.342, determined experimentally by Amendola et al. (2016). The object of this study was an SENB specimen of Ti-6-Al-4V manufactured by SLM following the standards ASTM E647-05 and ASTM E1290-07. The specimen geometric dimensions are: total specimen length, L=100 mm; distance between the specimen supports, S= 80 mm; specimen height, W= 20 mm; specimen thickness, B=20 mm, and a pre-crack, a i = 1mm. 4. Simulation Study In this study, to determine the solutions for SIF and JIT, two types of static tests were performed: with and without fatigue. To distinguish between these two types of tests, the static test without fatigue will be referred to simply as a static test, while the static test with fatigue will be referred to simply as a fatigue test. For the finite element analysis of SIF, JIT, and crack propagation, the Contour Integral method was used. The software used was Ansys. To study the influence of the mesh refinement, eight tests were performed with different degrees of refinement at the crack edge; for each crack length model of 3 mm, 5 mm, 7 mm, 9 mm, 11 mm and 11.64 mm. After deciding on the type of mesh geometry to be used, another study was carried out to analyse the model with or without using contact; this is using a pressure force that would have the same effect as the load. The applied force was 7500 N. The fixed supports were recreated using boundary conditions at the nodes of the elements, which are located 40 mm from the centre. The type of loading present in this study was performed using a periodic wave with a frequency of f= 20 Hz, a maximum force of 7500 N and a stress ratio of R= 0.1. Figure 2 presents the model used in the 3D simulation.

Fig. 2. Model used in 3DSimulation in Ansys: for initial simulation mesh with contacts (23049 elements and 36354 nodes).