Influence of temperature on the behaviour at fibre misalignment in thick-walled Fibre Reinforced Composites

温度对厚壁纤维增强复合材料纤维错位行为的影响

• 批准号: 428324840
• 负责人: Professor Dr.-Ing. Bodo Fiedler
• 金额: --
• 依托单位: Institut für Kunststoffe und Verbundwerkstoffe
• 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/428324840?language=en
• 关键词: Influence; temperature; behaviour; fibre; misalignment

Fibre reinforced polymers (FRP) are established as a design material for structural parts in various applications. However, manufacturing induced composite imperfections, in-plane as well as out-of-plane, is critical, because the fibres are no longer orientated in loading direction due to the misalignment, which reduces strength and stiffness of the laminate significantly. The aim of this research project is the investigation of the influence of structural discontinuities in the shape of local fibre misalignment (in-plane) and on laminate level layer waviness (out-of-plane) on the mechanical properties of FRP. A special focus is set on the influence of the ambient temperature on the behaviour of so called thick laminates under uniaxial compression and multiaxial loading conditions.When investigating a size effect of the mechanical properties of FRP, it is often not clear whether it is an actual size effect of the material or whether other influencing factors, such as a reduction in manufacturing quality with increasing thickness, play a role. In this case, defects that have been artificially introduced can provide further insights into the influence of production deviations in the scaling of FRP laminates, while ensuring a consistent production quality.The compressive behaviour of FRP is significantly influenced by the matrix properties, which are temperature-dependent. The basis of the investigations is therefore the characterization of the matrix with regard to the thermal and mechanical properties as well as the temperature-viscosity behaviour. The temperature-viscosity behaviour is decisive for the development of the HD-RTM process.The applicability of mechanical parameters and material properties determined in experiments with thin specimens to thick-walled structures has not been clarified and will be investigated within the framework of the project.Finally, the findings will be used for the multiaxial testing of test structures. Thus, the influence of fibre misalignments and displacements at different temperatures on component-like structures can be investigated and correlations for critical defects can be derived.

纤维增强聚合物（FRP）在各种应用中被确立为结构部件的设计材料。然而，制造诱导的复合材料缺陷，无论是面内还是面外，都是至关重要的，因为由于不对中，纤维不再在加载方向上定向，这大大降低了层压板的强度和刚度。本研究项目的目的是调查结构不连续的影响，在局部纤维错位的形状（面内）和层压水平层波纹（面外）对FRP的力学性能。特别关注环境温度对所谓的厚层压板在单轴压缩和多轴加载条件下的行为的影响。在研究FRP机械性能的尺寸效应时，通常不清楚这是材料的实际尺寸效应还是其他影响因素，例如随着厚度的增加制造质量的降低，起作用。在这种情况下，人为引入的缺陷可以进一步了解生产偏差对玻璃钢层压板结垢的影响，同时确保一致的生产质量。FRP的压缩性能受到基体性能的显著影响，而基体性能与温度有关。因此，研究的基础是表征基质的热性能和机械性能以及温度-粘度行为。温度-粘度特性是HD-RTM工艺发展的决定性因素。在薄试件实验中确定的力学参数和材料性能对厚壁结构的适用性尚未明确，将在项目框架内进行研究。最后，研究结果将用于试验结构的多轴试验。因此，可以研究不同温度下纤维错位和位移对类构件结构的影响，并推导出关键缺陷的相关性。