Development of a robust virtual design environment for structural composites

高性能碳纤维复合材料已日益成为大型商用飞机结构的首选材料。这些结构的适航性认证目前依赖于从数千个小规模试样测试到单个全尺寸测试的大量测试。在此期间，对元件、细节和子结构进行大量测试，以确定复杂载荷下的静强度和疲劳寿命。虚拟设计环境（VDE）的可用性，即几乎完全在计算机上完成设计的能力，从而减少对耗时和昂贵的测试的依赖，在减少设计周期和与设计和认证复合材料结构相关的成本方面起着关键作用。除了降低成本外，通过考虑新材料的可行性，强大的VDE还可以扩展复合材料的设计空间（纤维和树脂）、纤维结构、铺层和结构配置，否则太复杂而无法通过经验方法进行验证。基于申请人及其研究团队的以往经验，该研究的目的是通过将工艺和结构模型集成到一个开放源代码软件环境中的单一的、有效的、基于物理的计算工具中来创建VDE，以评估制造的大规模复合材料结构的完整性和耐久性。其目的是考虑复合材料结构的完整历史，因为它经历了从制造到其作为承重结构的工作环境的各个步骤。所取得的进展将形成一种新的设计方法的基础，其中控制结构复合材料的过程和损伤行为的所有参数的影响可以包括在设计中。这种能力将大大减少真实的试验次数和与目前在复合材料结构设计中采用的经验安全系数有关的费用。

High performance carbon-fibre composites have increasingly become the material of choice for large commercial aircraft structures. Certification for airworthiness of these structures currently relies on numerous tests ranging from thousands of small scale coupon tests to a single full scale test. In between, numerous tests are conducted on elements, details and sub-structures to determine static strength and fatigue lives under complex loadings. The availability of a virtual design environment (VDE), i.e. the ability to complete designs almost entirely on the computer and thus reducing the reliance on time consuming and costly tests, plays a critical role in the reduction of design cycle times and costs associated with designing and certifying composite structures. Beyond cost reductions, a robust VDE offers the possibility of expanding the design space for composite materials by considering the viability of new materials (fibres and resins), fibre architectures, lay-ups and structural configurations that are otherwise far too complex to certify through empirical approaches.Building on the previous experience of the applicant and his research team, the aim of the proposed research is to create a VDE by integrating the process and structural models into a single, efficient, physics-based computational tool within an open source software environment to assess the integrity and endurance of as-manufactured, large scale composite structures. The aim is to take into account the full history of the composite structure as it goes through the various steps, from manufacturing all the way to its working environment as a load-bearing structure. The advancements made will form the basis of a new design methodology where the effects of all parameters that control both the process and damage behaviour of structural composites can be included in the design. This capability will significantly reduce the number of real tests and costs associated with the use of empirical safety factors that are currently adopted in the design of composite structures.