Friction in composites forming

复合材料的成形技术已经发展到了一个广泛的范围。相应地，有大量的复合材料可用，例如干材料或用树脂预浸渍的材料，而纺织品结构可以采取许多形式，例如单向或编织。引入这些工艺的一个关键动机是提高自动化程度，从而减少周期时间和成本，提高可重复性和质量。然而，为特定应用开发适当的材料和工艺往往被证明是有问题的，工艺开发是一项成本高昂的经验性活动，成功的机会相当不确定。该项目的目标是获得复合材料成型中摩擦的基本科学理解，开发捕获适当机制的标准测试，并演示如何将这些测试和模型应用于案例研究组件的制造。研究的价值将通过将实验和建模应用于案例研究组件来证明，以量化产品质量的潜在改进。单向碳纤维和编织碳纤维将以干燥形式使用，并作为预浸料。将考虑工具或真空袋与复合材料之间以及层片之间的摩擦。将探索的加工路线将是一个巩固型的变形和披覆型的变形。在这两种情况下，理想化的几何形式将首先被用来获得基本的科学理解。在实验室规模的测试中的接触条件的观察将被用来揭示复合材料形成中的摩擦机制。将通过摩擦学实验室实验开发和验证各种元件（工具到层和层到层）之间接触的摩擦学模型。将开发标准化测试，以复制摩擦学测试中发现的机制的方式测量摩擦。一个案例研究几何将被用来理解的影响，形成的组成部分。这项工作将与工业合作伙伴密切合作，他们将协助提供材料，定义适当的测试方法，并帮助制定和实施案例研究。

A wide range of forming techniques have been developed for composites. There is a correspondingly large number of composite materials available, e.g. dry material or material pre-impregnated with resin, while the textile architecture can take many forms such as unidirectional or woven. A key motivation for introduction of these processes is increased automation, giving reduced cycle time and cost and increased repeatability and quality. However the development of the appropriate material and process for a given application has often proved problematic, with process development being a costly, empirical activity with a rather uncertain chance of success. The goal of this project is to gain a fundamental scientific understanding of friction in composites forming, to develop standard tests which capture the appropriate mechanisms, and to demonstrate how these tests and models can be applied to manufacture of a case-study component. The value of the research will be demonstrated by application of the experiments and modelling to the case study component to quantify potential improvements in product quality.Uni-directional and woven carbon will be used in dry form and as pre-prepreg. Friction between the tool or vacuum bag and the composite and between plies will be considered. Processing routes that will be explored will be a consolidation-type of deformation and a draping-type of deformation. In both cases idealised forms of geometry will first be used to gain the underlying scientific understanding. Observations of the contact conditions in laboratory-scale tests will be used to uncover the mechanisms leading to friction in composites forming. Tribological models of the contact between the various elements (tool to ply and ply to ply) will be developed and validated via tribological lab experiments. Standardised tests will developed to measure friction in a way that replicates the mechanisms found in the tribological tests. A case study geometry will be used to understand the implications for forming of components. The work will be in close collaboration with the industrial partners who will assist with supply of materials, definition of appropriate tests methods and help with the case study formulation and implementation.