Quantitative correlation of micro- and macromechanical parameters of endless fibre reinforced plastics

环形纤维增强塑料微观和宏观力学参数的定量相关性

• 批准号: 471651330
• 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
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/471651330?language=en
• 关键词: Quantitative; correlation; micro; macromechanical; parameters

Unidirectional continuous fibre-reinforced plastics (UD-FRP) have high weight-specific strength and stiffness as well as good energy absorption capacity and fatigue behaviour under fibre-parallel tensile load. For this reason, understanding the properties of FRP under fibre-parallel tensile load is of great importance. Due to the micromechanically heterogeneous structure, however, the consideration of composite properties is more complex than with metal materials and requires a deeper understanding of the damage behaviour and the underlying mechanisms. According to the literature, there are essential damage mechanisms for carbon fibre or glass fibre reinforcement with a thermoset matrix, e.g. fibre breakage, fibre debonding and matrix damage. Therefore, there are complex interactions between the mechanisms. In static, crash-relevant, and cyclic load cases, these micromechanical mechanisms are influenced differently by the fibre and matrix types and the properties of the fibre/matrix-interface, so that there is an optimum fibre/matrix combination for these load cases and their requirements. Although in the literature there are investigations on individual mechanisms and influencing factors, no studies on the interaction of all essential factors with uniform boundary conditions can be found. It is therefore not fully understood how the constituent properties influence the damage and the macro-mechanical parameters, such as tensile strength, and fatigue life. Various micromechanical models have been developed to investigate this topic, along with the three-dimensional Shear-Lag model (SLM) offers the greatest potential. The aim of this project is the further development of the Shear-Lag model for UD-FRP for different load cases (quasi-static load and fatigue) and the evaluation of the applicability of the model for different fibre/matrix combinations. A further goal is the prediction of the mechanical parameters by simulation so that the performance of UD-FRP can be optimized application-specifically by material selection.To achieve this goal, the shear-lag model will be further developed for these load cases. At the same time, the micro-mechanical input parameters of the model and the macro-mechanical parameters of different fibre/matrix combinations will be characterized experimentally. The predictive quality of the model will then be analysed to evaluate for which fibre/matrix combinations and which load cases the model is suitable. As a direct result of the applied project, a validated model for the prediction of the mechanical parameters will be developed. Furthermore, the understanding of the interaction between the influencing factors will be extended.

单向连续纤维增强塑料(UD-FRP)在纤维平行拉伸载荷下具有较高的比重量比强度和刚度以及良好的能量吸收能力和疲劳性能。因此，了解FRP在纤维平行拉伸荷载作用下的性能是非常重要的。然而，由于复合材料的微观非均质结构，复合材料性能的考虑比金属材料更复杂，需要对损伤行为和潜在机制有更深入的了解。根据文献，碳纤维或玻璃纤维增强热固性材料的损伤机理主要有纤维断裂、纤维脱粘和基体破坏。因此，这些机制之间存在着复杂的相互作用。在静态、碰撞相关和循环加载的情况下，这些微观机械机制受纤维和基质类型以及纤维/基质界面的属性的不同影响，因此对于这些载荷情况及其要求存在最佳的纤维/基质组合。虽然在文献中有对个体机制和影响因素的研究，但没有关于所有基本因素在统一边界条件下相互作用的研究。因此，还不能完全了解组成特性如何影响损伤和宏观机械参数，如抗拉强度和疲劳寿命。各种微观力学模型已经被用来研究这一问题，其中三维剪切滞后模型(SLM)提供了最大的潜力。本项目的目的是进一步发展UD-FRP在不同载荷情况(准静态载荷和疲劳)下的剪滞模型，并评估该模型在不同纤维/基质组合中的适用性。进一步的目标是通过模拟预测力学参数，从而优化UD-FRP的性能，特别是通过材料的选择。为了实现这一目标，将进一步建立适用于这些荷载情况的剪力滞模型。同时，对模型的微观力学输入参数和不同纤维/基质组合的宏观力学参数进行了实验表征。然后将分析该模型的预测质量，以评估该模型适用于哪些纤维/基质组合以及哪些载荷情况。作为应用项目的直接结果，将开发出用于预测力学参数的验证模型。此外，还将扩大对影响因素之间相互作用的理解。