## 5 Conclusions  
This work focused on applying the RPIM and comparing it with the well-established FEM for a modified bi-evolutionary topological optimisation algorithm inspired by the bone remodelling concept. The study investigated the topological optimisation of a generic automotive control arm. The initially constructed 3D model was converted to a simplified 2D layout. Evaluation of the obtained solutions revealed that RPIM-generated topologies with superior truss connections and a greater number of intermediate densities would considerably enhance the mechanical performance of a hypothetical part manufactured through additive manufacturing. Additionally, RPIM demonstrated acceptable convergence in traditional linear static analyses, suggesting its potential as a viable alternative to FEM in specific topological optimisation scenarios. Four designs were subsequently built based on a solution retrieved from the aforementioned algorithm, utilising material removal techniques commonly employed in the automotive industry for the component under study: a trussed design model, a model with circular material removal, a model with triangular removal, and a model replicating the previous one but with an increased outer thickness of 1.5 times the nominal thickness of the remaining model. A linear static analysis, conducted under the same conditions used in the optimisation algorithm, demonstrated that the design based on circular material removal exhibited the best stiffness and specific stiffness. This confirmed the initial hypothesis, as the circular shape facilitates a more uniform distribution of stresses throughout the structure, aligning with established mechanical design practices known to improve a structure's mechanical performance. The trussed and triangular models displayed comparable behaviour due to the similarities in their material removal principles. As anticipated, the thickness-differentiated model exhibited lower displacement and consequently higher stiffness compared with the single-thickness model. However, the resulting increase in mass and total volume did not correspond to any improvement in specific stiffness relative to the model it was based on (model 3). Minor discrepancies were observed in the von Mises stress fields and maximum stress values obtained from the different methods. Moreover, both FEM and RPIM produce similar displacement values. The results here presented show that RPIM is capable of producing very close results to FEM, being a numerical alternative to FEM in such topological optimisation problems.  
**Author Contributions:** Conceptualization, J.B. and A.P.; methodology, J.B. and A.P.; software, J.B. and A.P.; validation, J.B., C.O., and A.P.; formal analysis, J.B., C.O., and A.P.; investigation, J.B., C.O. and A.P.; resources, J.B. and A.P.; data curation, J.B., A.P., and C.O.; writing--original draft preparation, C.O.; writing--review and editing, J.B. and A.P.; visualization, J.B. and A.P.; supervision, J.B.; project administration, J.B.; funding acquisition, J.B. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.  
The author truly acknowledges the support provided by LAETA, under project UIDB/50022/2020 and the doctoral grant SFRH/BD/151362/2021 financed by the Portuguese Foundation for Science and Technology (FCT), Ministerio da Ciencia, Tecnologia e Ensino Superior (MCTES), Portugal.  
The authors declare no conflicts of interest.