Integrated forming and impact simulation models for rapid liquid composite molded lightweight structures

这项研究迫切需要开发一个集成的工艺-性能仿真平台，以准确预测制造的轻质液体复合材料模压结构的冲击响应。采用这些技术的第一个挑战是织物在快速预成型阶段对局部瑕疵的敏感性。高温和高速变形条件会加剧瑕疵严重程度，因此准确预测织物在这些极端条件下的响应是至关重要的。保持相应结构的碰撞安全性是另一个关键挑战，因为现有的复合材料碰撞模拟模型忽略了应变率和绝热加热对材料本构响应和失效起始的耦合效应等重要特性。为了满足这些需求，拟议的Discovery Grant研究计划将：(1)表征和模拟单向无卷曲织物在高温和变形速率下的本构响应，以形成成形模拟模型；(2)表征和模拟相应复合材料的应变率相关的本构响应和失效行为；(3)将本构/失效和成形过程模型集成到行业使用的有限元代码中，以模拟制造的轻质复合材料结构的冲击性能。一套现有的测试基础设施和光学应变测量系统与新设计的加载夹具相结合，将首次用于表征非卷曲织物在复合变形模式(拉伸-剪切、弯曲-剪切)下的温度和速率相关响应，同时能够监测局部变形机制。实验获得的本构模型将被开发并应用到新的多层织物成形模拟模型中。最先进的高速光学(1000万fps)和热成像系统与滑铁卢的动态测试设备相结合，将能够在一定的应变率范围(高达1000/S)下监控复合材料测试试件的温度和损伤演变。新的本构模型和失效准则将与成形模拟模型相结合，以预测复合材料结构的冲击性能。研究成果将被转移到具有极大潜力的行业，以颠覆当前的碰撞模拟方法，并支持下一代轻型汽车架构的广泛采用。除了商业化潜力和加拿大汽车行业的技术优势外，还将通过减少燃油消耗和二氧化碳排放以及提高车辆乘员安全来实现社会效益。在拟议的探索基金研究计划的过程中，总共将培训10名高技能的研究人员，他们将为加拿大的工业做好充分准备。

The proposed research addresses a critical need to develop an integrated process-to-performance simulation platform to accurately predict the impact response of as-manufactured lightweight liquid composite molded structures. The first challenge in adopting these technologies is the susceptibility of the fabric to localized defects during the rapid preforming stage. Defect severity is heightened by the elevated temperature and high-rate deformation conditions, thus, making it critical to accurately predict the fabric response under these extreme conditions. Maintaining crash safety of corresponding structures poses another key challenge since current crash simulation models for composites neglect important characteristics such as the coupled effect of strain rate and adiabatic heating on the material constitutive response and failure onset. To address these needs, the proposed Discovery Grant research program will: (1) Characterize and model the constitutive response of a unidirectional non-crimp fabric under high temperatures and deformation rates to inform a forming simulation model; (2) Characterize and model the strain rate-dependent constitutive response and failure behaviour of the corresponding composite material; (3) Integrate the constitutive/failure and forming process models into finite element codes used by industry to simulate impact performance of as-manufactured lightweight composite structures. A suite of existing testing infrastructure and optical strain measurement systems coupled with newly designed loading fixtures will be used to characterize for the first time the temperature and rate dependent response of the non-crimp fabric under combined modes of deformation (tension-shear, bending-shear), while enabling monitoring local deformation mechanisms. Experimentally informed constitutive models will be developed and implemented into novel multi-layer fabric forming simulation models. State-of-the-art high speed optical (10 million fps) and thermal imaging systems coupled with dynamic testing devices also available at Waterloo will enable monitoring of temperature and damage evolution in the composite test specimens under a range of strain rates (up to 1000 /s). The new constitutive models and failure criteria will be integrated with the forming simulation model to predict the impact performance of composite structures. The research outcomes will be transferred to industry with high potential to disrupt current crash simulation methods and support widespread adoption of next-generation lightweight vehicle architectures. Beyond commercialization potential and a technological advantage for the Canadian automotive sector, societal benefits will be realized through reduced fuel consumption and CO2 emissions and increased occupant safety in vehicles. A total of ten highly skilled researchers will be trained over the course of the proposed Discovery Grant research program who will be well prepared for the Canadian industry.