Mechanism-correlated characterization of the deformation and damage behavior of thermo-plastic-based fiber metal laminates for property-oriented process development

热塑性纤维金属层压板变形和损伤行为的机制相关表征，用于性能导向的工艺开发

• 批准号: 414332488
• 负责人: Professor Dr.-Ing. Guntram Wagner
• 金额: --
• 依托单位: Lehrstuhl für Werkstoffprüftechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/414332488?language=en
• 关键词: Mechanism; correlated; characterization; deformation; damage

The objective of the two-phase research project is the identification, analysis and assessment of influencing factors on the strength and durability of thermoplastic-based fiber metal laminates. The first funding period focuses on material development and the consolidation process. In a second funding period, the effect of forming technology on material integrity as well as component integrity will be investigated by means of a demonstrator component. According to the state of the art, the fatigue strength of thermoset-based fiber metal laminates is influenced, in particular, by their delamination behavior. Therefore, primary objective for the intended qualification of alternative thermoplastic-based fiber metal laminates is the investigation on the restraint of fatigue damage as a result of mechanical (blasting) and chemical (pickling) methods for surface pretreatment of the metallic component. The interfacial and microstructure formation in the fiber-reinforced polymer (FRP) and aluminum layers will be determined by means of materialographic methods, e.g., light microscopy (LiMi), scanning (SEM) and transmission electron microscopy (TEM), as well as computed tomography (CT). The identification of dominant damage mechanisms will be carried out in quasi-static and cyclic testing using extended instrumentation for the monitoring of damage-related physical parameters, e.g. changes in electric resistance and acoustic emission. For a more detailed analysis of damage mechanisms, stiffness gradients in the material volume in quasi-static in-situ tests will be visualized via CT using the novel approach of digital volume correlation (DVC). Based on the results of mechanical testing, a process-structure-property relationship will be formulated and recommendations for the parameterization of the process steps for the production of thermoplastic-based fiber metal laminates will be given. At the end of the first funding period, selected fiber-metal laminates are fundamentally characterized and their damage behavior is investigated systematically. Furthermore, suitable laminate configurations are available as starting material for forming processes which are to be investigated in the second funding period. In the second funding period, the influence of forming processes on the material behavior of fiber-metal laminates is to be determined by means of a formed demonstrator. Specimens will be resected from areas which are influenced, e.g., by fiber rearrangements in bending radius. These specimens will be analyzed under mechanical as well as materialographic aspects. A further focus is the generation of extended stress distri-bution, e.g., by superimposed temperature and humidity influence in fatigue testing, in order to investigate the material behavior under operating conditions.

该两阶段研究项目的目标是识别、分析和评估热塑性纤维金属层压板强度和耐久性的影响因素。第一个资助期侧重于材料开发和整合过程。在第二个资助期内，将通过演示组件来研究成型技术对材料完整性以及组件完整性的影响。根据现有技术，热固性纤维金属层压板的疲劳强度尤其受到其分层行为的影响。因此，替代热塑性纤维金属层压板的预期鉴定的主要目标是研究对金属部件表面预处理的机械（喷砂）和化学（酸洗）方法导致的疲劳损伤的抑制。纤维增强聚合物（FRP）和铝层中的界面和微观结构形成将通过材相方法确定，例如光学显微镜（LiMi）、扫描（SEM）和透射电子显微镜（TEM）以及计算断层扫描（CT）。主要损伤机制的识别将在准静态和循环测试中进行，使用扩展仪器来监测与损伤相关的物理参数，例如电阻和声发射的变化。为了更详细地分析损伤机制，准静态原位测试中材料体积的刚度梯度将使用数字体积相关 (DVC) 的新方法通过 CT 可视化。根据机械测试的结果，将制定工艺-结构-性能关系，并给出热塑性纤维金属层压板生产工艺步骤参数化的建议。在第一个资助期结束时，对选定的纤维金属层压板进行了基本表征，并系统地研究了它们的损伤行为。此外，合适的层压结构可用作成型工艺的起始材料，该成型工艺将在第二资助期进行研究。在第二个资助阶段，成形工艺对纤维金属层压板材料行为的影响将通过成形演示器来确定。样本将从受影响的区域切除，例如，受弯曲半径中的纤维重新排列影响的区域。这些样本将在机械和材相方面进行分析。进一步关注的是扩展应力分布的产生，例如通过疲劳测试中叠加的温度和湿度影响，以研究工作条件下的材料行为。