DEVELOPING THE NEXT GENERATION OF HYDROGEN ASSISTED FRACTURE MODELS

该项目旨在开发新一代多物理场和多尺度模型，可以预测氢脆引起的材料断裂，实现虚拟测试并防止灾难性故障。 氢气无处不在，具有显著的性质和应用。氢的同位素将为人类提供下半个世纪的核聚变燃料，而氢作为能源载体是解决能源危机最有希望的途径之一。尽管有这些机会，但一百多年来人们一直知道氢会导致金属结构的灾难性故障。这种现象不仅危及氢作为未来能源载体的作用，而且还继续限制现代钢铁在当前能源基础设施中的使用。金属材料的抗断裂性在氢的存在下急剧降低（高达90%！）并且对氢损伤的敏感性随着材料强度而增加。因此，氢辅助开裂在高强度钢中特别严重，缺乏了解已经停止了它们在能源，国防，运输和建筑部门的使用，牺牲了数十年的冶金进步。在现代高性能合金中，甚至在良性环境（例如，由于潮湿），其影响无处不在：从Leadenhall大楼的螺栓开裂到离岸结构倒塌。由于目前的工程方法主要是经验性的和高度保守的，因此迫切需要：（1）了解这种氢致降解的机制;（2）开发基于力学的模型，能够在与工程实践相关的尺度上再现微观结构相关的力学响应。该项目的成功将导致新一代的氢脆模型，能够定量预测氢辅助开裂的发生在相关的工程应用规模。该项目的主要目标如下：（1）开发一个多物理计算框架，能够处理工程实践中固有的大尺度，同时解决问题的微观结构性质。(2)通过进行关键实验获得对潜在物理机制的基本见解。(3)开发新的基于机制的本构模型，通过明确考虑潜在的物理机制来减少结晶。 (4)EPSRC研究领域：结构工程，制造技术，材料工程-金属和合金，能源应用材料

The project aims at developing a new generation of multi-physics and multi-scale models that can predict material fracture due to hydrogen embrittlement, enabling Virtual Testing and preventing catastrophic failures. Hydrogen is ubiquitous and has remarkable properties and applications. Its isotopes will provide the nuclear fusion fuel for humanity in the next half century and the use of hydrogen as energy carrier is one of the most promising solutions to our energy crisis. In defiance of these opportunities, hydrogen has been known for over a hundred of years to cause catastrophic failures in metallic structures. This phenomenon not only jeopardizes the role of hydrogen as a forthcoming energy carrier but also continues to restrict the use of modern steels in current energy infrastructure. The fracture resistance of metallic materials is drastically reduced in the presence of hydrogen (by up to 90%!) and the susceptibility to hydrogen damage increases with material strength. Thus, hydrogen assisted cracking is particularly severe in high-strength steels and the lack of understanding has halted their use in the energy, defence, transport and construction sectors, sacrificing decades of metallurgical progress. In modern high-performance alloys, hydrogen embrittlement is observed even in benign environments (e.g., due to humidity) and its impact is ubiquitous: from bolt cracking at the Leadenhall building to off-shore structural collapse. With current engineering approaches being mainly empirical and highly conservative, there is a strong need to: (1) understand the mechanisms of such hydrogen-induced degradation; and to (2) develop mechanistic-based models able to reproduce the microstructure-dependent mechanical response at scales relevant to engineering practice. The successful project will lead to a new generation of hydrogen embrittlement models, able to quantitatively predict the occurrence of hydrogen assisted cracking at a scale relevant to engineering applications. The main objectives of the project are the following: (1) Developing a multi-physics computational framework capable of dealing with the large scales inherent to engineering practice while resolving the microstructural nature of the problem. (2) Acquiring fundamental insight into the underlying physical mechanisms by performing critical experiments. (3) Developing new mechanism-based constitutive models that reduce empiricism by explicitly considering the underlying physical mechanisms. (4) Predicting cracking thresholds and subcritical crack growth rates in a mechanism-based framework, and validating predictions through advanced materials testing.EPSRC research areas:Structural engineering, Manufacturing technologies, Materials engineering - metals and alloys, Materials for energy applications