The team of highly qualified and motivated PhD students with 5 female and 9 male ESRs from three continents represented well the interdisciplinary character of the ETN with backgrounds in the fields of mechanical engineering, computational sciences and mathematics. THREAD’s training programme aimed at scientific skills in Cosserat rod models, their numerical treatment and practical application, transferable skills including high level experience in dissemination and communication as well as interdisciplinary and inter-sectoral experience. The local training in supervised individual research projects and local PhD programmes was accompanied by a comprehensive network-wide training programme with 14 network-wide training events, 6 industrial workshops and more than 40 secondments to academic and non-academic partners.
The ESRs focussed on the three research-related work packages on advanced constitutive laws, on interactions of 1D structures in a 3D world and on geometric numerical integration methods. They started with a literature review, defined test cases for validation of new computational models and considered industrial use cases in tight interaction with the non-academic partners. The inter-sectoral three-month secondments of all 14 ESRs provided deep insights into how modelling and simulation are utilised in virtual product development processes to address industrial challenges.
The physical phenomena in the deformation of electric cables, spiral strands, wire ropes and hollow endoscopes have been studied by test-rig experiments and by numerical simulations with newly developed methods and open-source software components in specially tailored simulation tools. This experimental work has provided the basis for designing novel constitutive laws which can deal with, e.g. variable axial forces, composite cross sections, hysteretic operators or data driven models. The analysis of contact and friction phenomena inside spiral strands and cable harnesses, in braiding processes and in ropeway systems has been addressed by improved modelling and simulation techniques that are implemented in the open-source software packages Odin and Exudyn and in the proprietary software Multifil for exploitation in industrial projects. Research on geometric integration methods with focus on adaptivity, robustness and adaptivity has shown their feasibility in the industrial context. Reduced order models with nonlinear normal modes were investigated as key technologies for further gains in efficiency.
THREAD has already been presented in as many as 26 high-quality research papers in reputable scientific journals from mathematics and engineering (14 more papers currently under review). The submission of up to 12 PhD theses is expected before the end of year 2024 including 5 theses that have already been successfully defended or are under review.
The ESRs contributed to a series of THREAD mini-symposia and special sessions at leading international conferences in this field such as WCCM 2020, ECMI 2021, NUMDIFF-16, ECCOMAS Congress 2022, ICIAM 2023 and the ECCOMAS Conferences on Multibody Dynamics (2021, 2023). The THREAD network has initiated a new series of biannual ECCOMAS Thematic Conferences on Highly Flexible Slender Structures (Rijeka 2023, Kaiserslautern 2025).
