## 4 Conclusions  
This study has provided valuable insights into the fatigue behavior of short glass fiber-reinforced Polyamide 6 (SGFR-PA6), a material of increasing importance in applications traditionally served by metals. Our investigation, utilizing monotonous fatigue tests with and without breaks, alongside the Locati method, has led to several important conclusions regarding the material's performance under cyclic loading conditions. Firstly, the differentiation between initial (or elastic) damage and plastic (or net) damage in the total damage observed from monotonous fatigue tests with breaks underscores the material's capacity for partial recovery between load applications. This phenomenon highlights the composite's inherent resilience to fatigue, with the elastic component of damage being recoverable upon the release of cyclic stress. The introduction of a model to identify net damage through variations in total energy per cycle relative to initial conditions represents a significant advancement in our understanding of fatigue processes in composite materials. This model provides a robust framework for predicting the onset of critical damage, thereby enhancing the material's application in engineering designs. Secondly, our findings confirm that the net critical damage in thermal fatigue processes for SGFR-PA6 stabilizes at values close to 15%, irrespective of the stress level applied. This stabilization indicates a threshold beyond which further stress does not proportionally increase the rate of damage accumulation, suggesting a material property that could be exploited in designing components subjected to high cyclic loads. Furthermore, the comparative analysis of the four Locati test variants reveals minimal influence from the number of cycles per step, the presence or absence of breaks, and the stress increase value between steps on the overall fatigue behavior of SGFR-PA6. This observation not only validates the efficiency of the Locati method in determining the fatigue limit but also suggests the potential for simplifying the test procedure without compromising the reliability of the results. The ability to define the fatigue limit from the individual net damage (D\({}_{\text{Nl}}\)) in a Locati test, as demonstrated by the step from which this parameter begins to increase, offers a practical and accurate method for evaluating the fatigue strength of SGFR-PA6. Figure 17: Individual net damage (D\({}_{\text{Nl}}\)) of Locati 4. This methodology promises to reduce the time and resources required for fatigue testing, facilitating quicker material evaluation and application in design processes. In conclusion, the research conducted provides a comprehensive assessment of the fatigue behavior of SGFR-PA6, offering critical insights into its damage recovery capabilities, the stability of its critical damage level under thermal fatigue, and the effectiveness of the Locati method for rapid fatigue limit estimation. These findings contribute significantly to the field of materials science, particularly in the optimization and efficient use of short fiber-reinforced thermoplastics in engineering applications. Future research will focus on exploring the Locati method under various environmental conditions, such as different temperatures and humidity levels, to better understand their impact on the fatigue behavior of SGFR-PA6. Additionally, we plan to test other types of short fiber-reinforced thermoplastics to determine the generalizability of our findings. Developing more advanced predictive models that incorporate real-time monitoring data and sophisticated error analysis techniques will also be a priority. These efforts will contribute to the broader goal of optimizing the use of short fiber-reinforced thermoplastics in engineering applications. Conceptualization, I.A.C. ; methodology, I.A.C. ; formal analysis, I.A.C., J.A.C., and S.D. ; data curation, I.A.C., S.D., and J.A.S.-A. ; writing--original draft preparation, I.A.C. ; writing--review and editing, J.A.C., D.F., J.A.S.-A., and S.D.