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

纤维增强薄壁部件的缠绕技术代表了一种成熟的制造技术。另一方面，在厚壁部件的情况下，由于所用树脂体系的放热固化反应而发生高温，这可能会由于所用材料的中等导电性而导致部件损坏。因此，目标是有预测的可能性，以排除此类事件。该问题代表了空间相关的各向异性材料性质的化学-热-力学问题。特别是，由于纤维张力、固化和加工速度引起的残余应力的预测是进一步感兴趣的。为了提供一种预测工具，在这里，在有限元方法的框架内，需要进行一些基础研究。这些涉及(1)根据交联度和存在的各向异性对基本材料的流变、热和机械性能进行完整的表征，(2)缠绕过程中过程的整体计量记录和相关技术工具的实施，(3)旋转制造过程和相关固化过程中过程的多物理耦合建模，以及(4)开发用于预测残余应力的模拟工具，从而提供工艺优化策略的可能性。首先，对所应用的树脂体系和所使用的纤维进行表征，以使三维材料模型变得适用或可开发。然后，开发了缠绕过程中关于内部和外部过程的热和机械记录的测量实施。在此基础上，在有限元方法的框架内，推导了展开、旋转结构的运动学以及相应的平衡方程和相关的数值解。除了材料模型的开发和模型方程的相关材料参数的确定之外，还将提供验证实验，以便能够对高度复杂的行为的预测质量做出陈述。

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.