Additive manufacturing (AM) has enabled the fabrication of complex geometries directly from the design data and gained a lot of interest. However, AM products can contain pores, which can significantly reduce fatigue life. The main focus of this work is to evaluate the effect of the pores in Ti6Al4V dog-bone samples, produced by AM, and propose a methodology to estimate the fatigue life reduction due to the internal pores. The bond-based Peridynamics (PD) fatigue model was utilised to analyse the fatigue life of the defect-free sample with the calibrated PD parameters. Moreover, a numerical model is developed to investigate two types of porosities in a system. The application of the PD model showed a capability of crack nucleation prediction for the titanium alloy samples under cycling loading. The predicted results are compared with experimental data using the stress-life (S-N) curve. Furthermore, this paper presents a numerical approach to assess the influence of the pore location and size on the fatigue life of Ti6Al4V. The PD predictions indicated the critical pore characteristics and the applicability of the developed PD model on samples with low porosity for high cycle fatigue-loaded applications.

增材制造（AM）使直接从设计数据中制造复杂的几何形状成为可能，并且引起了广泛的兴趣。但是，增材制造产品可能包含孔，这会大大降低疲劳寿命。这项工作的主要重点是评估AM生产的Ti6Al4V狗骨头样品中孔的影响，并提出一种方法来估算由于内部孔导致的疲劳寿命降低。利用基于键的Peridynamics（PD）疲劳模型通过校准的PD参数分析无缺陷样品的疲劳寿命。此外，开发了一个数值模型来研究系统中的两种孔隙率。PD模型的应用显示了在循环载荷下钛合金样品的裂纹成核预测能力。使用应力寿命（SN）曲线将预测结果与实验数据进行比较。此外，本文提出了一种数值方法来评估孔的位置和大小对Ti6Al4V疲劳寿命的影响。PD的预测表明了关键的孔隙特性，以及所开发的PD模型在低孔隙率样品上的适用性，适用于高循环疲劳载荷应用。