# An Overview of Smart Composites for the Aerospace Sector
## 4 Discussion
### Topic Analysis  
Based on the results obtained above, the development of a topical analysis is proposed below. Topical analysis in bibliometric reviews is a technique used to identify and group topics or areas of research within a set of scientific publications [52]. The six themes defined from the above analysis are (i) advanced materials; (ii) composite structures; (iii) functional properties; (iv) analysis and computational methods; (v) structural components; and (vi) monitoring and performance. Table 5 shows each of the defined topics, as well as the keywords and records identified. This grouping provides a logical and comprehensive organization of the terms, reflecting the main areas of interest of the dataset: Advanced materials (t1) and composite structures (t2) focus on the fundamental composition and construction of the materials; functional properties (t3) highlight the unique characteristics that make these materials valuable for specific applications; analysis and computational methods (t4) represent the tools used to study and design these materials and structures; structural components (t5) are narrowed down to specific elements used in engineering applications, while monitoring and performance (t6) address the practical aspects of applying and evaluating these materials in real-world scenarios. The results reflect the distribution of research attention on six key topics related to advanced materials and composite structures. Advanced materials (t1) stands out as the dominant theme, representing 29.7% of the total. This suggests that advanced materials are the main focus of interest in this field, probably due to their wide applicability in sectors such as energy, construction, and aerospace. This prominence may be driven by the development of innovative technologies such as nanocomposites, carbon nanotubes, and graphene, which offer unique properties and great potential to solve technological challenges. On the other hand, monitoring and performance (t6) is in second place with 17.4%, reflecting a growing concern for assessing and ensuring the performance of materials and structures in real applications. This interest could be related to the need to monitor structural integrity in real time, especially in critical industries such as automotive, aeronautics, and civil infrastructure. Furthermore, this approach is aligned with global trends towards sustainability and material life cycle optimization. In contrast, topics such as functional properties (t3) (2.6%) and analysis and computational methods (t4) (5.5%) have a lower representation, which could indicate that they are more specialized or complementary areas within the general field. However, their relevance should not be underestimated, as these areas are fundamental for developing specific properties (such as piezoelectricity or shape memory) and for modeling the behavior of materials using advanced computational tools. Taken together, these results show \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Denomination** & **Research Topic** & **Keywords** & **Results** \\  & & & **n (\%)** \\ \hline t1 & Advanced materials & Nanocomposites, carbon nanotubes, & \\  & & graphene, fibers and fiber reinforced plastics & \\ t2 & Composite structures & Laminated composites, composite structures, & \\  & & laminating and reinforcement & \\ t3 & Functional properties & Piezoelectricity, shape memory effect and & \\  & & intelligent materials & \\ t4 & Analysis and & Finite element method, shear deformation & \\  & & and vibration analysis & \\ t5 & Structural components & Plates (structural components) and actuators & \\ t6 & Monitoring and performance & Structural health monitoring and performance & 340 (17.4%) \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Research topics. a balanced picture where some topics are major drivers of the field, while others act as technical or emerging pillars to underpin broader advances. Following the topic analysis, the evolution of topics over time is studied.