Thick-walled fiber composite components in winding technology - experiment and modeling

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The winding technique for fiber-reinforced, thin-walled components represents an established manufacturing technology. In the case of thick-walled components, on the other hand, high temperatures occur due to the exothermic curing reaction of the resin systems used, which can lead to damage of the components due to the moderate conductivity of the materials employed. Therefore, the aim is to have prediction possibilities to exclude such events. The problem represents a chemo-thermomechanical problem for spatially dependent anisotropic material properties. In particular, the prediction of residual stresses due to filament tension, curing, and process speed are of further interest. In order to provide a prediction tool, here within the framework of the finite element method, a number of fundamental investigations need to be addressed. These concern (1) the complete characterization of the basic materials with regard to their rheological, thermal and mechanical properties depending on the degree of crosslinking and the anisotropy present, (2) the holistic metrological recording of the processes in the winding process and the associated technical tooling implementation, (3) the multi-physics coupled modeling of the processes during the rotational manufacturing process and the associated curing, and (4) the development of a simulation tool for the prediction of residual stresses and thus the possibility to provide a process optimization strategy. First, the applied resin system and the fibers used are characterized so that a three-dimensional material model becomes applicable or developable. Then, a measurement implementation in the winding process is developed with regard to the thermal and mechanical recording of the internal and external processes. Based on this, the derivation of the kinematics of developing, rotating structures as well as the corresponding balance equations and the associated numerics are derived within the framework of the finite element method. In addition to the material model development and the identification of the associated material parameters of the model equations, validation experiments are then to be provided in order to be able to make statements about the prediction quality of the highly complex behavior.