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Virtual Testing of Non-Crimped Fabric Composites

无卷曲织物复合材料的虚拟测试

基本信息

批准号：
2091551
负责人：
金额：
--
依托单位：
Imperial College London
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2017
资助国家：
英国
起止时间：
2017 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=studentship-2091551
关键词：
Virtual Testing Non Crimped Fabric

项目摘要

This research project is within the framework of the 'Wing of Tomorrow' project, whose key objective is the design and manufacturing of a complete wing structure from advanced carbon based composites and simulated using Predictive Virtual Testing techniques. The initiative of this research is based on the advantages that Non-Crimp Fabric composites (NCF) (e.g. good mechanical properties, improved impact properties compared to pre-impregnated materials (prepregs), low production cost, high drapeability) can offer in aerospace applications, resulting in lighter structures with reduced operational and manufacturing costs.Non-Crimped-Fabrics have been under development for some time; they provide certain advantages over traditional pre-impregnated (prepreg) composite materials, mainly a reduction in unit cost and manufacturing cost. Specifically, the non-crimped fabric composites can be produced with an out-of-autoclave manufacturing process. For example, resin transfer moulding (RTM) which uses woven laminates, is relatively low cost and takes advantage of easy handling of large sheets of the fabric.In terms of strength, NCF do have improved through-thickness properties without significant drop in in-plane performance. In addition, NCFs offer new challenging possibilities to designers and manufacturers, given their higher degree of tailorability, greater deposition rate and improved impact performance when compared to well-established prepreg composites.The objectives/aims could be summarized as follows:- A significant goal of the project is the development and validation of Finite Element (FE) simulation tools (i.e. Virtual Testing) which can reduce costs and time within the industrial development cycle since full-scale experimental tests are prohibitively expensive and time consuming.- The failure mechanism in compression of the NCF is going to be further investigated and understood through this project, since NCFs do suffer from low compressive properties due to their internal structure (i.e. fibre waviness).- Furthermore, the present PhD project aims to implement physically-based constitutive failure criteria, namely LaRC05, in NCF composites. Moreover, the mechanical performance of a typical aircraft structure (e.g. skin-stringer panel as part of the wing box structure) will be analysed, both computationally (Finite Element Methods) and experimentally under several loading cases, such as tension, compression, shear, cyclic load tension, impact and compression after impact.- The computational analysis is performed with the application of finite element methods through Dassault Systèmes Abaqus commercial software. The validation and development of the constitutive failure criteria is a cornerstone of this research and will be carried out at tow level before proceeding with the structural level analysis. Coupon level testing will be performed to identify and characterise the typical failure mechanisms with the assistance of several inspection techniques, among which fractography is emphasized.Hence, a material mechanical properties database will be created to validate all the models developed in this project. As structural level are defined, those models developed in the length scale of a laminate, which are ideal for preliminary design and structural optimisation due to their ability to provide quick predictions.By the end of this project it is believed that the ability to predict the composite performance up to failure and beyond, in a Virtual Modelling environment, will be significantly improved, having a positive influence to a wide range of industrial applications.

该研究项目属于“明日之翼”项目的框架，该项目的主要目标是设计和制造由先进碳基复合材料制成的完整机翼结构，并使用预测性虚拟测试技术进行模拟。这项研究的倡议是基于无卷曲织物复合材料（NCF）在航空航天应用中的优势（例如，与预浸渍材料（prepregs）相比，良好的机械性能，改善的冲击性能，低生产成本，高悬空性），从而降低了操作和制造成本，从而实现了更轻的结构。无卷曲织物的开发已经有一段时间了；与传统的预浸渍（prepreg）复合材料相比，它们具有一定的优势，主要是单位成本和制造成本的降低。具体地说，非卷曲织物复合材料可以用非高压灭菌器制造工艺生产。例如，树脂转移成型（RTM）使用编织层压板，成本相对较低，并且利用易于处理大片织物的优势。就强度而言，NCF确实改善了通过厚度的性能，但面内性能没有明显下降。此外，与成熟的预浸料复合材料相比，nfc具有更高的可定制性、更高的沉积速率和更好的冲击性能，为设计师和制造商提供了新的挑战。目标/目的可以总结如下：-项目的一个重要目标是开发和验证有限元（FE）仿真工具（即虚拟测试），这可以减少工业开发周期内的成本和时间，因为全面的实验测试非常昂贵且耗时。-由于NCF的内部结构（即纤维波纹）导致其压缩性能较低，因此该项目将进一步研究和了解NCF的压缩失效机制。此外，目前的博士项目旨在在NCF复合材料中实施基于物理的本构失效标准，即LaRC05。此外，一个典型的飞机结构（如蒙皮弦板作为翼箱结构的一部分）的力学性能将进行分析，计算（有限元方法）和实验几种载荷情况下，如拉伸，压缩，剪切，循环载荷拉伸，冲击和冲击后压缩。-通过Dassault systemmes Abaqus商业软件，应用有限元方法进行计算分析。本构破坏准则的验证和开发是本研究的基石，在进行结构层面分析之前，将在两个层面上进行。在几种检测技术的帮助下，将进行接触面水平测试，以识别和表征典型的失效机制，其中强调了断口学。因此，将创建一个材料力学性能数据库来验证该项目中开发的所有模型。随着结构水平的定义，这些模型在层压板的长度尺度上发展，由于它们能够提供快速预测，因此对于初步设计和结构优化是理想的。在该项目结束时，相信在虚拟建模环境中预测复合材料性能直至失效及以后的能力将得到显着改善，对广泛的工业应用产生积极影响。