Motivation and research problem

The digital twin concept has matured into a crucial cornerstone of many engineering disciplines since the end of the last century. Digital twins in civil engineering, however, are usually tailored to specific use cases, due to the unique character of civil engineering structures, or to specific subsystems of structures (e.g. structural subsystem, mechanical subsystem). The uniqueness of digital twins in civil engineering, the complex communication networks, and the heterogeneity of interfaces and models comprising the digital twins result in a lack of interoperability and objective quality assurance strategies. To improve quality and fully exploit the potential of digital twins in civil engineering, a clear mathematical understanding of the semantic structure of digital twins is required, which will provide formal concepts for quality assurance (including consistency checks, verification, and validation) of digital twins.

Research objectives

The proposed project aims to provide a methodology to enable reliable quality assurance of digital twins in all design phases and at all levels of abstraction – from creating abstract, conceptual models to implementing specific, practical applications. In the proposed project, the focus is placed on digital twins for infrastructure, although all approaches proposed in this project will be generally applicable. First, a domain analysis for taxonomic representation of digital twins will be performed to appropriately describe concepts and entities relevant to digital twins. Next, the work program is devoted to three levels of abstraction. On each level, (i) modeling concepts and (ii) approaches towards quality assurance of these modeling concepts will be proposed. The modeling concepts will couple abstract mathematical approaches based on relational algebra, categorical ontology protocols, and type theory (“meta-metamodeling”), diagrammatic semantics that are easily comprehensible by engineers (“metamodeling”), and engineering models established in numerical analysis and building information modeling (“modeling”). The approaches towards quality assurance are essentially based on an abstract mathematical description, utility-based metrics, and a tangle-based blockchain architecture, introduced to validate the digital twins during their lifetime (Figure 1).

Expected results

It is expected that a mathematical understanding of the semantic structure of digital twins will be formalized. On this basis, it is further expected that objectively verifiable and generally applicable semantic modeling concepts for digital twins in civil engineering will be provided, serving as a basis for quality assurance at all levels of abstraction. Modeling errors will be avoided in early design phases, the digital twin implementation will be efficient and technology-independent, entailing a viable basis for increasing the quality of digital twins for civil infrastructure.