Dynamic Failure of Light Weight Materials and Structures

轻质材料和结构的动态失效

• 批准号: RGPIN-2018-04026
• 负责人: Worswick, Michael
• 金额: $ 4.01万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=668912
• 关键词: Dynamic; Failure; Light; Weight; Materials

The proposed research addresses the critical need to develop a simulation platform to predict failure of light weight automotive, aerospace and defence vehicle structures under the high strain rate conditions associated with crash events and ballistic impact. A key challenge in the adoption of these very high strength, low density or thinner materials is their lower ductility, making it critical to accurately predict the onset of failure under crash and ballistic impact conditions. This issue is exacerbated by significant levels of heat generation through plastic work during failure; thus thermal softening and adiabatic shear localization processes must be considered in predicting failure, in addition to constitutive strain rate sensitivity and microstructural damage. ******To address this need, the proposed program of Discovery Research will:******1. Characterize and model damage evolution during high strain rate loading, focusing on advanced- and ultra-high strength steels;******2. Characterize the thermal conditions associated with high strain rate failure processes, in particular shear localization, and develop models of adiabatic shear localization; ******3. Implement advanced high strain rate failure criteria within finite element codes used by industry, thereby ensuring dissemination and adoption of the research outcomes.******This research will utilize the extensive suite of high strain rate constitutive and fracture characterization infrastructure already in place at Waterloo, easily the largest such laboratory in an academic setting in North America, featuring new CFI-funded ultra-fast optical cameras (10 million fps) and high speed thermal cameras (90,000 fps). The new imaging infrastructure will enable high fidelity measurements of fracture processes at high rates of strain. These in situ measurements will be complemented by optical microscopy-based and tomography measurements of damage in recovered as-tested samples. Momentum-trapping fixtures within the current tensile split-Hopkinson bar allow soft recovery of samples prior to fracture, enabling characterization of damage as a function of deformation and loading conditions. State-of-art experiments will inform new models of damage and fracture under high strain rate loading. These will see application in the development of future lightweight, crashworthy vehicles, increasing occupant safety and enhancing the competitiveness of the Canadian auto, aero and defense sectors.******A total of eight graduate students will be trained over the course of this Discovery Research program. These researchers will become skilled in state-of-the-art experimental and analytical techniques within the field of material response to gross plastic deformation and impact. Their recruitment within Canadian industry and academe will further enhance Canada's future competitiveness.***********

拟议的研究解决了开发模拟平台的关键需求，以预测与崩溃事件和弹道影响相关的高应变率条件下轻型汽车，航空航天和防御车辆结构的故障。采用这些非常高的强度，低密度或较薄材料的关键挑战是它们的较低延展性，这对于准确预测崩溃和弹道冲击条件下的故障发作至关重要。在失败过程中，通过塑料工作的大量产生加剧，这个问题加剧了。因此，除组成性应变率灵敏度和微结构损伤外，还必须考虑预测失败的热软化和绝热剪切定位过程。 ******为了满足这一需求，拟议的发现研究计划将：****** 1。在高应变率加载期间表征和模型损伤演变，重点是高级和超高强度钢； ****** 2。表征与高应变率故障过程相关的热条件，特别是剪切定位，并开发绝热剪切定位的模型； ****** 3。 Implement advanced high strain rate failure criteria within finite element codes used by industry, thereby ensuring dissemination and adoption of the research outcomes.******This research will utilize the extensive suite of high strain rate constitutive and fracture characterization infrastructure already in place at Waterloo, easily the largest such laboratory in an academic setting in North America, featuring new CFI-funded ultra-fast optical cameras (10 million fps) and high快速热摄像机（90,000 fps）。新的成像基础设施将使骨折过程以高应变速率进行高保真度测量。这些原位测量将通过基于光学显微镜的基于光学显微镜和层析成像测量的互补测量值进行补充。当前拉伸裂缝杆内的动量捕获灯具允许在断裂前进行样品的软恢复，从而使损伤表征是变形和加载条件的函数。最先进的实验将为高应变率负载下的新损伤和断裂模型提供信息。这些将在开发未来轻巧，撞车的车辆，提高乘员安全并增强加拿大汽车，航空和国防部的竞争力的发展中的应用。这些研究人员将在对总塑性变形和影响的材料响应领域内熟练掌握最先进的实验和分析技术。他们在加拿大工业和学术界的招聘将进一步增强加拿大未来的竞争力。*******************************************************************