The significant dispersion in fatigue properties is a prevalent attribute observed in metals manufactured by the Additive Manufacturing (AM). To ascertain the safety of components subjected to low cycle fatigue (LCF) loadings at a temperature of 550 °C, it is necessary to carry out a fatigue reliability assessment of AM metals. Nevertheless, the number of LCF life tests is limited owing to time-consuming nature of test and high total production cost of AM materials. Such a small size dataset cannot satisfy the criteria of the traditional reliability assessment method. This work aims to develop a novel method to evaluate the LCF reliability of 316L stainless steel manufactured by laser-based powder bed fusion of metals (PBF-LB/M) technology. Firstly, the Weibull model is coupled with the Coffin-Manson-Basquin relationship in order to characterize the dispersion of life data points at various strain levels. Secondly, reliability results from a small size dataset show a maximum relative error in fatigue life of less than 25 %, which is similar to results from a large size dataset and the traditional method using fatigue data from public sources. Among this step, the remora optimization algorithm is firstly applied to calculate the characteristic parameters of newly-proposed method. Thirdly, the LCF reliability of PBF-LB/M 316L based on the small size dataset is evaluated. The is equivalent to 44 % of . Finally, the PBF-LB/M 316L is compared with traditional 316L considering the reliability. The LCF properties of PBF-LB/M 316L is similar to the traditional 316L at 50 % reliability, however it’s slightly worse at 95 % reliability.

中文翻译：

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使用 remora 优化算法从小尺寸数据集估计 PBF-LB/M 316L 钢低周疲劳概率曲线的方法

疲劳性能的显着分散是增材制造 (AM) 制造的金属中观察到的普遍属性。为了确定在 550 °C 温度下承受低周疲劳 (LCF) 载荷的部件的安全性，有必要对增材制造金属进行疲劳可靠性评估。然而，由于测试耗时且增材制造材料的总生产成本较高，LCF寿命测试的数量受到限制。如此小的数据集无法满足传统可靠性评估方法的标准。本工作旨在开发一种新方法来评估采用激光粉末床金属熔合 (PBF-LB/M) 技术制造的 316L 不锈钢的 LCF 可靠性。首先，Weibull 模型与 Coffin-Manson-Basquin 关系相结合，以表征不同应变水平下寿命数据点的离散度。其次，小规模数据集的可靠性结果显示疲劳寿命的最大相对误差小于 25%，这与大规模数据集和使用公共来源疲劳数据的传统方法的结果相似。在这一步中，首先应用remora优化算法来计算新提出的方法的特征参数。第三，评估了基于小数据集的PBF-LB/M 316L的LCF可靠性。相当于 的 44%。最后，考虑可靠性，将PBF-LB/M 316L与传统316L进行比较。 PBF-LB/M 316L 的 LCF 特性与传统 316L 相似，可靠性为 50%，但可靠性为 95% 时稍差。