Modelling and simulation of the manufacture-dependent shrinkage behaviour of glass-fibrereinforced 36epoxy resins for the improved prediction of surface-waviness and warpage

• Applicants: Professor Dr.-Ing. Maik Gude; Professor Dr.-Ing. Christian Hopmann
• Subject Area: Plastics Engineering
• Term: from 2018 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 415849481

The aim of the collaborative project is to gain an improved understanding of the processdependent shrinkage induced volumetric change during processing of thermoset fibre reinforced plastics (FRP). It is known that the specific choice of process parameters has direct influence on the quality of the component and in particular on process induced deformations and surface waviness. However, the influence of the processing pressure on the resin cure behaviour has so far not been the subject of systematic process-related investigations. Within the framework of the project, novel test methods are being developed and used for the analysis of the thermo- and chemo-mechanical phenomena in laboratory scale. Especially the relationships between the process parameters temperature and pressure as well as the relevant phenomena resin reaction, shrinkage and interface formation between fibre and matrix are examined using an online sensor system. In this way, essential aspects, which until now have been neglected in the prediction of residual stresses, can be identified. Based on the experimental findings, parameterised material models are developed that form the basis for a multi-scale simulation approach. This is simultaneously developed by the project partners both for the numerical prediction of the residual stress state inside the composite materialas well as for the computation of the resulting surface waviness. The phenomena occurring within the material and at its surface are to be linked causally to one another for the first time in order to achieve a continuous modelling strategy. The fundamental investigation of the physical matrix properties under real curing conditions and the development of a multi-scale simulation of residual stresses and surface effects can increase the predictability of current simulation methods and substantially increase the process and material understanding of thermoset FRP.

• DFG Programme: Research Grants