Experimental characterization and numerical simulation of the automated fiber placement (AFP) process for thermoplastic fiber-reinforced plastics

热塑性纤维增强塑料自动纤维铺放 (AFP) 工艺的实验表征和数值模拟

• 批准号: 325153381
• 负责人: Professor Dr.-Ing. Klaus Drechsler
• 金额: --
• 依托单位: Lehrstuhl für Carbon Composites
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/325153381?language=en
• 关键词: Experimental; characterization; numerical; simulation; automated

The efficient, high-quality and reproducible production of thermoplastic fiber-reinforced plastic components requires automated manufacturing processes. Due to its load-path oriented deposition of fibers to near-net-shape components, automated fiber placement (AFP) has particularly great potential. With proper temperature control during thermoplastic AFP (TP-AFP) in-situ consolidation is possible, i.e. a consolidation in place of the process without downstream thermosetting. However, the understanding of the process is still far from reaching the level of maturity necessary for a broad industrial application of TP-AFP. For example, it is still difficult today to define suitable process windows for the most important key parameters such as laser power, velocity and compaction pressure so that a consistently high quality of components is assured. In particular, the prediction of residual stresses and distortion is only solved insufficiently and process calibration is often based on a trial-and-error method. The reasons for this discrepancy between low prediction accuracy and high industrial demands can likewise be ascribed to possibilities of experimental characterization and modeling and simulation that are not yet maxed out. Therefore, the aim of the applicants is to improve process understanding in the area of TP-AFP fundamentally through novel experimental studies and methods of numerical simulation. On the experimental side, the focus will be on the integration of fiber optic sensors into the AFP process. For the first time, fiber Bragg grating (FBG) sensors will be used to monitor the characteristic TP-AFP process variables (consolidation pressure and laminate temperature) at key points, including within the laminate, thus allowing a reliable determination of the process-induced residual stresses subsequent to manufacturing. A long-term goal is the surveillance of the component in operation by so-called structure health monitoring (SHM). With respect to numerical simulation of the TP-AFP process, there is still a lack today of a holistic approach to reliably predict the critical component properties. Therefore, the focus in this project will be on the development and gradual integration of a corresponding overall process model based on nonlinear finite element methods (FEM). The aim is to achieve a significant improvement in prediction accuracy over the current state of research with this TP-AFP overall process model. Finally, the integration of experiment, modeling and simulation is also a particular feature of this project. For example, the simulation activities will consistently access the experimental results obtained in parallel so that all the sub-models can be appropriately parameterized. This integrated approach ultimately ensures the highest possible quality of the developed process model.

要高效、高质量和可重复地生产热塑性纤维增强塑料部件，需要自动化制造过程。由于其以负载路径为导向将纤维沉积到近净形状的部件，自动纤维放置(AFP)具有特别大的潜力。如果在热塑性AFP(TP-AFP)过程中进行适当的温度控制，原位固结是可能的，即在不需要下游热固性的情况下进行原位固结。然而，对该过程的了解还远远没有达到TP-AFP广泛工业应用所需的成熟水平。例如，今天仍然很难为最重要的关键参数(如激光功率、速度和压制压力)定义合适的工艺窗口，以确保始终保持高质量的部件。特别是，对残余应力和变形的预测解决得不够充分，工艺校准往往是基于试错法。预测精度低和工业需求高之间出现这种差异的原因同样可以归因于尚未达到最大限度的实验表征、建模和模拟的可能性。因此，申请者的目的是通过新颖的实验研究和数值模拟方法从根本上提高对TP-AFP领域的过程理解。在实验方面，重点将放在将光纤传感器集成到AFP过程中。光纤布拉格光栅(FBG)传感器将首次用于监测关键位置的TP-AFP工艺变量(固结压力和层压温度)，包括层压板内部，从而可靠地确定制造后工艺引起的残余应力。一个长期目标是通过所谓的结构健康监测(SHM)对运行中的部件进行监测。关于TP-AFP过程的数值模拟，目前仍然缺乏一种整体方法来可靠地预测关键组分的性质。因此，本项目的重点将是开发和逐步集成基于非线性有限元方法的相应全过程模型。其目的是通过这种TP-AFP全过程模型在预测精度方面比目前的研究状况有显著的提高。最后，实验、建模和仿真的一体化也是本项目的一大特色。例如，模拟活动将一致地访问并行获得的实验结果，以便所有子模型可以被适当地参数化。这种集成的方法最终确保了所开发的流程模型的最高质量。