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

拟议的研究解决了迫切需要开发一个集成的过程性能仿真平台，以准确地预测制造的轻质液体复合材料成型结构的冲击响应。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缺陷的敏感性。由于温度升高和高速率变形条件，缺陷的严重性增加，因此，准确预测织物在这些极端条件下的响应至关重要。保持相应结构的碰撞安全性提出了另一个关键的挑战，因为目前的复合材料碰撞模拟模型忽略了重要的特性，如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。为了满足这些需求，拟议的发现资助研究计划将：（1）表征和模拟单向非卷曲织物在高温和变形率下的本构响应，以告知成形模拟模型;（2）表征和模拟相应复合材料的应变率相关本构响应和失效行为;（3）将本构/破坏模型和成形过程模型集成到工业界使用的有限元程序中，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，将用于表征第一次的温度和速率依赖的非卷曲织物的组合模式下的变形（拉伸剪切，弯曲剪切）的响应，同时使监测局部变形机制。实验告知本构模型将开发和实施到新的多层织物成形模拟模型。Waterloo还配备了最先进的高速光学（1000万fps）和热成像系统以及动态测试设备，可在一系列应变率（高达1000 /s）下监测复合材料试样的温度和损伤演变。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很大潜力的行业，以破坏当前的碰撞模拟方法，并支持下一代轻型车辆架构的广泛采用。除了加拿大汽车行业的商业化潜力和技术优势外，还将通过减少燃料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。共有10名高技能的研究人员将在拟议的发现赠款研究计划的过程中接受培训，他们将为加拿大工业做好充分的准备。

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.