Analysis and modeling of the damage behavior of long-fibre-reinforced semi-crystalline thermoplastics considering fibre length and fibre curvature

考虑纤维长度和纤维曲率的长纤维增强半结晶热塑性塑料的损伤行为分析和建模

• 批准号: 416461157
• 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: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/416461157?language=en
• 关键词: Analysis; modeling; damage; behavior; long

In addition to the established short-fibre reinforced thermoplastics, the importance of thermoplastic materials with longer discontinuous fibres (LFT: long fibre reinforced thermoplastics) is continuously increasing. The microstructure of LFT is strongly influenced by the respective manufacturing process and is characterised by locally varying fibre orientations, fibre lengths and fibre curvature.If an LFT is loaded increasingly, there are different failure mechanisms whose characteristics depend each on the load, but also on the characteristics of the microstructure. In the literature, there are indeed works that describe the failure behaviour of these composites by modelling individual damage mechanisms, however, the distinction between different parallel or successively expiring mechanisms and in particular, the description on the basis of physical characteristics is a challenging and yet unsolved problem. Especially for LFT, the influence of fibre curvature on the strength can be called unexplored.The planned project aims in this research gap. Preliminary investigations at IKV have shown that the material behaviour of LFT can be represented in good accuracy using material models based on the mean-field (MF) theory with practicable calculation times. The damage behaviour, which is mostly initiated at the micro level, cannot be adjusted using the MF models. The aim of the project is therefore the exemplary description of the damage behaviour of LFT considering different fibre lengths and fibre curvatures using the mean-field theory.

除了已建立的短纤维增强热塑性塑料外，具有较长不连续纤维的热塑性材料（LFT：长纤维增强热塑性塑料）的重要性也在不断增加。 LFT 的微观结构受到各自制造工艺的强烈影响，其特征是局部变化的纤维取向、纤维长度和纤维曲率。如果 LFT 的负载不断增加，则会出现不同的失效机制，其特征分别取决于负载，但也取决于微观结构的特征。在文献中，确实有一些作品通过对单个损伤机制进行建模来描述这些复合材料的失效行为，然而，不同并行或连续失效机制之间的区别，特别是基于物理特性的描述是一个具有挑战性的且尚未解决的问题。未解决的问题。特别是对于LFT，纤维曲率对强度的影响堪称未探索。本计划的项目正是针对这一研究空白。 IKV 的初步研究表明，使用基于平均场 (MF) 理论的材料模型和实用的计算时间可以很好地准确地表示 LFT 的材料行为。损伤行为主要是在微观层面引发的，无法使用 MF 模型进行调整。因此，该项目的目的是使用平均场理论对考虑不同纤维长度和纤维曲率的 LFT 损伤行为进行示例性描述。