# Development and Application of Digital Twin Technique in Steel Structures
## 2 Literature Bibliometric Analysis
### Publication Analysis  
To analyze the publication details of these literatures, the focus was primarily on the publication dates, which can reflect the development of the digital twin technique in steel structures. The number variation of the publications is reflected in Figure 2 from 2009 to 2024, indicating that the digital twin technique has developed significantly in the recent years. Note that the number of publications has increased rapidly from 2020 to 2024, whose trend highlights the growing interest and the active research in the digital twin technique for steel structures [1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11]. The yearly variation of the publication numbers aligns with the universal trend where an emerging topic firstly experiences a period of steady growth followed by a rapid increase.  
The situation of publications in various journals is subsequently discussed, and Figure 3 provides a clear visual indication of which journals focus on the topic of the digital twin technique in steel structures. Obviously, many publications on this topic have appeared in journals like \"_Materials Science and Engineering\"_[35; 55] and \"_Acta Materialia_\"[110; 117], which primarily focus on the properties and microstructure of structural materials, and the results indicate that the digital twin technique is utilized to explore the material mechanisms of steel at the micro level. Meanwhile, some studies on the digital twin technique of steel structures are published in journals around the theme of structural engineering, such as \"_Engineering Failure Analysis_\" [19; 22], \"_Engineering Structures_\" [1; 92], and \"_Structures_\" [41; 50]. It is indicated that newly developing technologies are initially applied at the material level before gradually being adopted at the structural level.  
Figure 2: Publication development in recent years.  
Additionally, several journals focused on health monitoring and fatigue assessments are reported based on the digital twin technique, highlighting its significant role in structural maintenance and management.  
Literature regions also make significant contributions to advancing the digital twin technique for steel structural engineering. These regions not only indicate the development of this technique, enabling simulation, real-time monitoring, and optimization for structural performance, but also present the cooperation across multiple disciplines for the digital twin technique, involving structural engineering, computer science, and data analytics. Therefore, bibliometric analyses of literature regions and their correlations are of great interest. The regions of the literatures in the current study are displayed in Figure 4.  
These literatures are primarily from China [6; 21; 36], Singapore [1; 25; 122], Australia [27; 50; 59], Japan [20; 35; 67], Korea [58; 100; 124], the United States [2; 16; 57], England [3; 33; 42], Spain [19; 48; 68], Italy [15; 22; 66], and Germany [63; 72; 82], as marked in red on the world map. The black lines connecting these regions indicate research collaborations between countries about the digital twin  
Figure 4: Publication regions of current research.  
Figure 3: Publication distribution of the literature.  
technique in steel structures. Notably, China, England, America, Singapore, Australia, and Italy have frequent collaborations on this topic.