FOR 1224:  CFRP-Aluminium Transition Structures in Lightweight Design

• Subject Area: Materials Science and Engineering ; Humanities ; Mechanical and Industrial Engineering
• Term: from 2010 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 101721741

To adapt component properties to local requirements the application of combined FRP (fibre reinforced plastics)-metal structural components in lightweight design is increasing. Novel joining concepts are necessary for the weight and process optimised realisation. The Research Unit's objective is to develop integral transition structures between aluminium and CFRP (carbon fibre reinforced plastic), which lead to a lean and weight-minimised design and to a reduction of production steps as well as to advantages concerning optimised load application.
The Research Unit started work in summer 2010. Three of the five project partners are developing novel types of joints using their core competence and produce them as well. Thereby textile, welding and casting technologies are used. The other partners support the development process with experimental and numerical investigation for validation and enhancement of the solutions.
All associates undertook comprehensive investigations and started preliminary tests to check feasibility of all concepts. Selecting of one concept, first attempts production processes, FE-modelling and concerning fracture behaviour of decoupled connection zones in CFRP-aluminium transition structure under static load application were made. In this case, the transition structure is realised by titanium wire loops. The wire loops are connected to the carbon fibre by textile technologies and to the aluminium sheet by laser beam welding or alternatively by casting technologies.
The gained technical experiences provide a basis for determining the interdisciplinary specifications for all concepts. Due to the immense freedom of scope and a variety of process and material parameters, design solutions will be gradually improved during the project.
In the first project, phase results for connections are available, which are optimised for static load application, furthermore manufacturing concepts for the joints and investigations concerning corrosion resistance. Further exercises for a potential second phase are to develop selected solutions for different applications and the optimisation of the design for dynamic loads.

• DFG Programme: Research Units

Projects

• Computational modeling and evaluation of the failure behavior of various metal fiber transition structures (Applicant Kienzler, Reinhold )
• Corrosion and corrosion-induced failure of hybrid CFRP-Al-transition-structures (Applicant Zoch, Hans-Werner )
• Development of CFRP-metal compounds by casting technology (Applicant Busse, Matthias )
• Failure behaviour of cfrp-aluminium-transition structures under various quasi-static and cyclic loading conditions (Applicant Zoch, Hans-Werner )
• Sub-project: Development and evaluation of textile fibre-metal-connections (Applicant Herrmann, Axel )
• Thermal joining of integral CFRP-metal joints (Applicant Vollertsen, Frank )

• Spokesperson: Professor Dr.-Ing. Axel Herrmann