Design strategies and production processes of strength-optimised lightweight structures made of composites with variableaxial fibre architecture (OptiTex)

纺织增强塑料，一个仍然年轻的材料家族，承诺大量高潜力的轻量化解决方案。在这里，纺织纤维的布局可以适应复杂的局部变化的力流方向，类似于自然界中的建筑。基体材料也是专门为负载条件选择的，主要用于纺织品增强的保护和稳定以及产生均匀的力分布。对于各种纺织增强复合材料结构，其强度要求主导着设计过程，但其要求比刚度驱动设计要高得多。为了充分利用新型纺织增强材料组的高强度潜力，必须提供适当的纺织和塑料技术，以及基于物理的失效标准的材料分析和优化策略，考虑到纺织工艺的特定制造参数的限制。为此，为了开发具有可变轴向纺织品增强的强度优化复合材料，在工艺步骤、材料构造、计算和制造之间建立非常密切的联系是绝对必要的。因此，在这个合作研究项目中，一方面是在学科建模、仿真和优化之间进行密集的跨学科合作，另一方面是在给定纤维布局的纺织品预制体的制造和高纤维体积含量的巩固之间进行合作。因此，目前计划的合作项目与仿生学领域的研究项目明显不同，后者主要涉及刚度优化。在拟议的研究项目中，将研究由定制纤维放置（TFP）技术制造的薄壁和厚壁复合结构，以及具有部分可调经纱放置（MAG-KV）的多轴无卷曲织物。它们都允许可变轴向纤维增强布局，并适合大规模生产。研究项目的第一阶段包括设计和验证特定薄壁演示，以使用开发的面向过程的模拟和优化方法实现最大强度极限。在此背景下，也将阐明金属承载区面向纺织品设计的几个方面。通过研究平面和空间形状薄壁试件而开发的基于技术的方法将通过拉伸、弯曲和扭转载荷的断裂试验来验证。基于这些知识，演示和设计的复杂性将在研究项目的第二阶段通过分析厚壁复合材料而增加。

Textile-reinforced plastics, a still young family of materials, promise a substantially high potential for lightweight solutions. Here, the textile fibre layout can be adapted for complex locally changing force flow orientations similarly to constructions in nature. The matrix material, which is also specifically chosen for the load conditions, serves mainly the protection and stabilisation of the textile reinforcement as well as the generation of a uniform force distribution. For a variety of textile reinforced composite structures the strength requirements dominate the design process, which, however, is much more demanding than stiffness driven designing. To fully exploit the high strength potential of the new textile reinforced material group adequate textile and plastic technologies have to be provided as well as material-oriented analysis and optimisation strategies with physically based failure criteria considering the limits of the specific manufacturing parameters of the textile process. For this purpose, a very close link between the process steps material construction, calculation and manufacturing is absolutely necessary in order to develop strength-optimised composites with variableaxial textile reinforcement. Thus, within this collaborative research project, an intensive interdisciplinary cooperation between the disciplines modelling, simulation and optimisation, on the one hand, as well as manufacturing of textile preforms with a given fibre layout and its consolidation with high fibre volume contents on the other hand, is intended. Hence, the present planned collaborative project differs clearly from research projects in the field of bionics, which mainly deals with stiffness optimisation.Within the proposed research project, both thin-walled and thick-walled composite structures manufactured by the technologies Tailored Fibre Placement (TFP) and multi-axial non-crimp fabric with partial adjustable warp fibre placement (MAG-KV) will be investigated. Both of them allow a variableaxial fibre reinforcement layout and qualify for large-scale production. The first period of the research project comprises designing and validation of specific thin-walled demonstrators to achieve the maximum strength limits using the developed process-oriented simulation and optimisation methods. In this context, aspects about textile-oriented designing of metallic bearing areas will be clarified too. Technology-based methods developed by investigating plane and spatially shaped thin-walled specimens will be experimentally validated by fracture tests with tension, bending and torsion loads. Based on this knowledge the demonstrator and design complexity will be increased by analyzing thick-walled composites within the second period of the research project.