EPSRC supported EngD project: Thermo-Mechanical Modelling for Structural Ceramics

EPSRC 支持的工程项目：结构陶瓷的热机械建模

• 批准号: 2351147
• 金额: --
• 依托单位: University of Birmingham
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2351147
• 关键词: EPSRC; supported; EngD; project; Thermo

Fatigue fracture is one of the failure modes in engineering ceramics where crack initiates, propagates, and finally results in failure under cyclic thermal loading. The efficient prediction of fatigue crack growth helps make engineering decisions on product durability. The conventional Paris law or J-integrals are not enough to predict crack growth in complex 3D geometries such as 3D perioidic structures from additive layer manufacturing. As an alternative method, the Phase Field models have been receiving increasing attention. In this approach it is possible to model both plastic and elastic deformations with a time in microcracked ceramics. The model predictions can also be used to track weaker zones in the structure and the severity of the applied loading conditions on the product durability. There is a knowledge gap in extending the Phase Fieldd models for elasto-plastic ceramics and measuring model input parameters such as fracture toughness, separation energy, cohesive strength, fatigue parameters for such complex structures such as honeycombs. In this work, Phase Field models will be developed to understand the durability of the microcracked systems and novel experimental techniques will be developed for measuring model parameters by utilizing facilities like high temperature bending test, Dynamic Mechanical Analyser, high-temperature impulse excitation, and nanoindentation. The model predictions will be validated on model materials under thermal shock load conditions. Similarly, these models will be used to explain the revesible grain growth and hysteresis in the elastic properties of microcracked ceramics.This project will specifically address some of the product development and quality control needs of JM. The EngD student will work as an integral part of thermal processing group and quality control teams. JM is building an enhanced capability in this area, enabling the model driven manufacturing & design. The EngD researcher will play a key role within this team; developing bespoke measurement methods, fracture model for a given product formulations. The focus of the EngD will be the fundamental R&D needs of the group, but also being involved in trials and implementation of models in commercial environment and support different manufacturing sites in Europe. For any concern with Brexit, this position is fully paid and sponsored.

疲劳断裂是工程陶瓷在循环热载荷作用下裂纹萌生、扩展并最终导致失效的失效模式之一。疲劳裂纹扩展的有效预测有助于产品耐久性的工程决策。传统的Paris定律或j积分不足以预测复杂3D几何形状的裂纹扩展，例如来自增材层制造的3D周期结构。相场模型作为一种替代方法，越来越受到人们的重视。在这种方法中，有可能模拟微裂纹陶瓷的塑性和弹性变形随时间的变化。模型预测还可用于跟踪结构中的薄弱区域以及应用负载条件对产品耐久性的严重程度。在扩展弹塑性陶瓷的相场模型和测量诸如蜂窝等复杂结构的断裂韧性、分离能、内聚强度、疲劳参数等模型输入参数方面存在知识空白。在这项工作中，将开发相场模型来了解微裂纹系统的耐久性，并将开发新的实验技术来测量模型参数，利用高温弯曲测试、动态机械分析仪、高温脉冲激励和纳米压痕等设备。模型预测将在热冲击载荷条件下的模型材料上进行验证。同样，这些模型将用于解释微裂纹陶瓷弹性性能中的可逆晶粒生长和滞后。该项目将具体解决JM的一些产品开发和质量控制需求。工程系学生将成为热处理组和质量控制团队的重要组成部分。JM正在这一领域建立增强的能力，使模型驱动的制造和设计成为可能。工程学研究人员将在这个团队中发挥关键作用；开发定制的测量方法，断裂模型为给定的产品配方。工程师的工作重点将是满足集团的基本研发需求，但也会参与商业环境中模型的试验和实施，并支持欧洲不同的制造基地。出于对英国脱欧的担忧，这个职位是全额支付和赞助的。