Experimental and numerical investigations of laminated, fibre reininforced plastics under crash loading

碰撞载荷下层压纤维增强塑料的实验和数值研究

• 批准号: 404502442
• 负责人: Professor Dr.-Ing. Christian Hopmann
• 金额: --
• 依托单位: Institut für Kunststoffverarbeitung (IKV) in Industrie und Handwerk an der RWTH Aachen
• 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 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/404502442?language=en
• 关键词: Experimental; numerical; investigations; laminated; fibre

The dimensioning of carbon fibre reinforced plastics (CFRP) can achieve a high accuracy based on quasi-static material properties and material models for static loads. The use of CFRP in crash relevant applications requires the consideration of the strain rate dependency of the mechanical properties, which is particularly pronounced for polymer matrices. Known strain rate effects are for example the embrittlement and hardening at impact loading. Goal of the project is the generation of new findings in damage mechanisms and evolution in unidirectional reinforced CFRP (UD-CFRP) laminates under impact loading and their numerical representation on components scale. Additionally, the development of robust testing methods and an RVE serve the needs for reliable scientific results concerning strain rate dependent material properties.In this project, adequate test methods will be developed, which enable a reliable determination of the mechanical properties of UD-CFRP at crash relevant strain rates. The material behaviour under highly dynamic loading will be modelled and understood on this basis using a multiscale modelling approach.The input parameters for the material models will be determined from highly dynamic tests with neat resin und unidirectional reinforced specimens in the entire relevant strain rate spectrum. An existing drop weight tower will be used for this purpose, which requires the development of fixtures, specimen geometries and the adaptation of suitable measurement instrumentations.A representative volume element (RVE) incorporating fibre, matrix and the interface will be used to investigate the material behaviour on the micro scale. This RVE provides on the one hand knowledge in strain rate effects and, on the other hand, its suitability for the numerical generation of mechanical properties will be investigated. Furthermore, a continuum mechanical description of UD-CFRP is aspired to represent the strain rate dependent, anisotropic material behaviour on the meso scale. The representation of plasticity and damage evolution is a key aspect here. Based on this, a macro model will be set up, which uses the mentioned continuum mechanical model. Investigations of the delamination behaviour of laminates under impact loading are used to develop a finite element formulation, which includes multiple laminate layers and also the consideration of delamination effects in a single element. A validation of the macro model will be performed with numerical and experimental investigations of a demonstrator part.

碳纤维增强塑料（CFRP）的尺寸可以基于准静态材料特性和静态载荷的材料模型实现高精度。在崩溃相关应用中使用CFRP需要考虑机械性能的应变率依赖性，这对于聚合物矩阵特别明显。已知的应变率效应例如，在冲击负荷时的互惠和硬化。该项目的目的是在损坏机制中产生新发现和在撞击负载下层压层层压板的单向增强CFRP（UD-CFRP）的演变以及其在组件量表上的数值表示。此外，强大的测试方法和RVE的开发满足了有关应变率依赖性材料特性的可靠科学结果的需求。在本项目中，将开发出适当的测试方法，这可以可靠地确定UD-CFRP在崩溃相关的应变速率时的机械性能。高度动态载荷下的物质行为将在此基础上使用多尺度建模方法进行建模和理解。材料模型的输入参数将根据整个相关应变速率光谱中的整洁树脂和单向单向增强样品的高度动态测试确定。现有的下降重量塔将用于此目的，该目的需要开发固定装置，样品几何形状和适应合适的测量仪器的适应性。融合纤维，矩阵和界面的代表性音量元素（RVE）将用于研究微尺度上的材料行为。该RVE一方面提供了应变率效应的知识，另一方面，将研究其对机械性能的数值生成的适用性。此外，UD-CFRP的连续机械描述被兴奋地表示应变率依赖性的，各向异性材料行为。塑性和损害进化的表示是这里的关键方面。基于此，将建立一个宏模型，该模型使用上述连续机械模型。对层压载荷下层压板的分层行为的研究用于开发有限元公式，其中包括多个层压层层，还考虑了单个元素中对分层效应的考虑。宏观模型的验证将通过对演示器部分的数值和实验研究进行。