Experimental and virtual analysis of draping effect and of their impact on the structural mechanical behaviour of composite components

悬垂效应及其对复合材料部件结构力学行为影响的实验和虚拟分析

基本信息

批准号：
287275762
负责人：
Professor Dr.-Ing. Maik Gude
金额：
--
依托单位：
Institut für Leichtbau und Kunststofftechnik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/287275762?language=en
关键词：
Experimental virtual analysis draping effect

项目摘要

The mass of load-carrying structural components can be considerably reduced by using high-performance fibre reinforced plastics. This material class, however, is not yet well-established for safety-relevant medium- and high-volume applications, since the real material behaviour is not sufficiently predictable. One reason is the considerable discrepancy between the real material behaviour, which is significantly influenced by process control, and the idealising assumptions of the available models for structural simulation. Depending on the complexity of the geometry of the component, the fibre architecture is very inhomogeneous and includes varying fibre orientations, varying fibre volume contents and local draping effects like overlaps, gaps and undulations. Only if those draping effects are diagnosed by experiments and are suitably considered in structural simulation, it will be possible to reliably construct complexly shaped composite components.Hence, objectives of the project are the development of methods to precisely detect draping effects in unidirectionally reinforced composites, the formulation of material models to describe the material impact of those draping effects, and the development of a continuous virtual process chain. Using the example of unidirectional non-crimped carbon fibre/epoxy resin composites, the draping effects arising from the preforming process will be specifically considered for construction. Firstly, experimental investigations are conducted to examine how discontinuities develop during draping and how they affect the properties of the composite. Based on that, the impact of those imperfections on the structural mechanical behaviour is investigated and quantified, partly by means of in-situ computer tomography. In order to consider draping effects in the frame of a CAE chain, they need to be detected by draping simulation. Therefore, draping simulations are conducted and experimentally validated using the example of a generic demonstrator component. For structural mechanical analysis of draping effects, simulation models at meso level will be developed and validated to discretely represent the fibre architecture of the non-crimped fabric including all relevant draping effects. Based on both the experimental investigations and the numerical studies at meso level, homogenised material models at macro level will be developed. These macro mechanical models shall describe the deformation and damage behaviour of the inhomogeneous material with sufficient accuracy, including draping effects. The final objective of the project is to properly represent the identified draping effects as well as their structural mechanical impact within a completed CAE chain. Such a continuous process and structural simulation chain promises great advantages for the design of composite components with non-crimp fabrics and, consequently, also an improved exploitation of the lightweight potential of high-performance composite materials.

通过使用高性能纤维增强塑料，可以大大减少携带负载结构成分的质量。但是，由于实际物质行为不足以预测，因此该材料类别尚未确定与安全相关的中型和高容量应用。原因之一是真实物质行为之间存在很大的差异，实际物质行为受过程控制的显着影响，以及对结构模拟的可用模型的理想化假设。根据组件的几何形状的复杂性，纤维结构非常不均匀，包括纤维方向不同，纤维体积内容物以及局部悬垂效果（例如重叠，间隙和起伏）。只有通过实验诊断出这些悬垂效应并在结构模拟中进行适当考虑，才有可能可靠地构造复杂形状的复合成分。因此，项目的目标是开发精确检测垂直效应的方法，以无关紧要的强化复合材料，材料模型的形成，描述了这些材料的延续构成的材料构成，并构成了造成效果的效果，并具有一定的效应，并构成了一项效果。以单向非犯罪纤维/环氧树脂复合材料的示例，将专门考虑由预制过程产生的悬垂效应。首先，进行了实验研究以检查悬垂过程中不连续性的发展以及它们如何影响复合材料的性质。基于此，研究和量化了这些缺陷对结构机械行为的影响，部分是通过原位计算机断层扫描的。为了考虑在CAE链的框架中悬垂效应，需要通过悬垂模拟来检测它们。因此，使用通用演示器组件的示例进行了悬垂模拟并实验验证。为了对悬垂效应进行结构性机械分析，将开发并验证中层的模拟模型，以离散地表示非裂缝织物的纤维结构，包括所有相关的悬垂效应。基于在中索水平的实验研究和数值研究，将开发宏观水平的同质材料模型。这些宏观机械模型应以足够的精度（包括悬垂效应）来描述不均匀材料的变形和损伤行为。该项目的最终目的是正确地表示已确定的悬垂效果及其在完整的CAE链中的结构机械影响。这种连续的过程和结构仿真链有望在设计具有非脆性织物的复合组件的设计方面具有很大的优势，因此，也可以改善对高性能复合材料轻巧潜力的利用。