FibreCast - material singularities and multidimensional connections in FFRP (filled fibre reinfoced polymer)

• Applicants: Professor Dr.-Ing. Christoph Gengnagel; Professor Dr.-Ing. Volker Schmid
• Subject Area: Structural Engineering, Building Informatics and Construction Operation
• Term: from 2015 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 277966554

The aim of the projekt is to continue generic research into a novel, detachable and non-detachable technology for highly efficient connections in slender bar structures made of FRP hollow sections or wooden bars. An important innovation will be the first-ever comprehensive research on cast connection joints made of filled fibre-reinforced polymer (FFRP).The previous research results of the applicants demonstrated that the performance of cast FFRP joints is large enough to generate connection areas with the same load bearing capacity as the connected FRP or timber components. Due to the cold casting technique, it is possible to connect FFRP directly with timber or fibre-reinforced plastics. These positive material properties, and the free formability of FFRP, enable highly efficient, though still insufficiently researched connection concepts. Current research focusses on nodes with geometrically low complexity and a rotationally symmetric or planar connection geometry.In order to exploit the enormous potential of FFRP joints, further in-depth research is required. The subject of this application includes the continuation of FFRP material investigations and the further development of novel concepts for micro-reinforcement in the connection area as well as the optimization of FFRP mechanical properties by heat treatment processes. This work will be combined with the continuation of the prototypical development of reinforced, detachable connection nodes with spatial form closure from FFRP. For this purpose, the computer-aided tool environment and manufacturing processes developed in the previous research project will be utilized and expanded.Given FFRP joint technology also promises advantages for non-detachable bar connections, the field of investigation will also be extended into non-detachable, geometrically complex three-dimensional nodes. The investigation into material-suitably compacted connection geometries should significantly increase the robustness of the connections.Previous research has highlighted the need for a fundamental study of the influence of manufacturing tolerances on the load-bearing capacity of form-fitting FFRP compounds. The proposed project will therefore present new possibilities for non-contact measurement in order to determine the manufacturing tolerances of FFRP nodes, and subsequently control or reduce them.The present application builds on the research conducted so far. The project continues research focused on essential questions in the field of a novel FFRP connection technology for fibre-based, slender, beam elements in construction.

• DFG Programme: Research Grants