An ultrasonic based measurement method considering viscoelastic properties to characterize the fibre matrix adhesion of organic sheets and their realistic modelling

一种考虑粘弹性的基于超声波的测量方法，用于表征有机片材的纤维基体粘附力及其真实建模

• 批准号: 495847374
• 负责人: Professor Dr.-Ing. Bernd Henning
• 金额: --
• 依托单位: Fachgruppe Kunststofftechnologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/495847374?language=en
• 关键词: ultrasonic; based; measurement; method; considering

Fibre-reinforced plastics are becoming increasingly important due to the advantageous synergy between lightweight plastics and durable fibres. They are particularly attractive to the automotive industry due to their low weight. However, the understanding of materials is still insufficient, especially for thermoplastics-based fibre composites. The properties of fibre composites are significantly influenced by the fibre matrix adhesion (FMA), implying that the quantification of FMA is of great interest for quality assessment. However, as of now only destructive testing methods on specially manufactured test specimens (e.g. "Single-Fibre Pull-Out Test") are available. A non-destructive characterization and monitoring of the FMA for real components is therefore not possible.The aim of this research project is the development of an ultrasound-based measuring method, which enables the characterization of the fibre matrix adhesion of organic sheets, as well as their realistic modelling. Starting points are the classical laminate theory (CLT), which is an established method for the design of multilayer composites, and an acoustic measurement method based on Lamb waves in plate waveguides, which was developed at the Measurement Engineering Group. The classical laminate theory assumes an ideal adhesion between the individual elements of the multilayer composite, which is why an extension to a non-ideal FMA must first be made in order to achieve the objective. In addition, high-frequency acoustic waves in fibre composites are influenced by the viscoelastic properties of the material. As could be shown in preliminary work, these lead to a deviation between mechanically and acoustically determined material parameters (e.g. Young's modulus). Therefore, the acoustic measurement method has to be extended or adapted to take these into account. By subsequently linking the two methods, a novel measurement procedure will be developed which allows the identification of the component-related parameters of the extended CLT model on the basis of the macroscopic overall material behaviour. Since this method works non-destructively, the feasibility and suitability in principle of the measuring method developed here for a later application for preventive maintenance, long-term material monitoring and 100% testing will be demonstrated. With these tools, the influence of FMA is investigated on the basis of selected material combinations, i.e. by varying the FMA, in order to gain a deeper understanding of material behaviour that can be taken into account in future component design processes.

由于轻质塑料和耐用纤维之间的有利协同作用，纤维增强塑料变得越来越重要。由于其重量轻，它们对汽车行业特别有吸引力。然而，对材料的理解仍然不足，特别是对热塑性塑料基纤维复合材料。纤维复合材料的性能受纤维基体粘附力（FMA）的显著影响，这意味着FMA的定量化对于质量评估具有重要意义。然而，到目前为止，只有专门制造的试样上的破坏性测试方法（例如“单纤维拔出测试”）可用。因此，不可能对真实的组件进行FMA的非破坏性表征和监测。本研究项目的目的是开发一种基于超声的测量方法，该方法能够表征有机片材的纤维基质粘附力，以及它们的逼真建模。出发点是经典的层压理论（CLT），这是一个既定的方法，设计多层复合材料，和声学测量方法的基础上兰姆波在板波导，这是在测量工程组开发。经典的层压理论假设多层复合材料的各个元件之间的理想粘附，这就是为什么必须首先扩展到非理想FMA以实现目标的原因。此外，纤维复合材料中的高频声波受材料的粘弹性影响。如在初步工作中所示，这些导致机械和声学确定的材料参数（例如杨氏模量）之间的偏差。因此，声学测量方法必须扩展或调整以考虑这些因素。通过随后连接这两种方法，将开发一种新的测量程序，它允许识别的扩展CLT模型的宏观整体材料行为的基础上的组件相关的参数。由于该方法是非破坏性的，因此将证明在此开发的测量方法在原则上的可行性和适用性，用于预防性维护，长期材料监测和100%测试。通过这些工具，可以在选定材料组合的基础上研究FMA的影响，即通过改变FMA，以便更深入地了解材料行为，并在未来的组件设计过程中加以考虑。