Simulating nucleation and short crack propagation using cellular automaton in gradient microstructures

使用元胞自动机模拟梯度微结构中的成核和短裂纹扩展

• 批准号: RGPIN-2018-05291
• 负责人: Bocher, Philippe
• 金额: $ 3.35万
• 依托单位: École de technologie supérieure
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=713577
• 关键词: Simulating; nucleation; short; crack; propagation

The proposed research is a continuation of previous discovery grants dedicated to the development of Cellular Automata (CA) methods applied to micromechanics. Thanks to this support, CA have been used to simulate cold creep / fatigue interactions in titanium alloys and localise stress distributions at the microstructural scale in polycrystals. In the present proposal, CA will be further develop to investigate crack initiation and propagation in material including microstructure gradients. This will help developing statistical based models for the fatigue life prediction of surface treated parts. CA, which are fully discrete, spatial-distributed, dynamical systems, serve as an alternative framework for mathematical descriptions and analysis of physical systems. Despite providing computational advantages, CA have not been extensively used in the framework of material science and mechanical engineering and the present candidate is a leader in this domain. The principal and long-term objective of the proposal is to developed CA models able to calculate the crack initiation and propagation from the stress and strain heterogeneities induced by surface treatment processes and applied loads, allowing the development of a statistical approach. Secondary objectives include further development of experimental techniques to calibrate and validate the developed models by documenting the adaptation of the microstructures during fatigue tests for various microstructures and alloys. Surface treatment such as machining, surface peening (hammer or shot), carburizing or induction hardening will be investigated as they are some of the surface treatments investigated by the candidate. Experimental validations will also be covered by the present proposal. The scale at which the measurements have required the development of original and precise techniques that are now available for further material investigation. The statistical results gathered by the CA models will be integrated to various microstructural-based model for fatigue life prediction.

拟议的研究是先前发现资助的延续，致力于开发应用于微力学的元胞自动机（CA）方法。得益于这种支持，CA 已被用于模拟钛合金中的冷蠕变/疲劳相互作用，并在多晶的微观结构尺度上局部化应力分布。在目前的提案中，CA 将进一步发展以研究材料中的裂纹萌生和扩展，包括微观结构梯度。这将有助于开发基于统计的模型来预测表面处理零件的疲劳寿命。 CA 是完全离散的、空间分布的动态系统，可作为物理系统数学描述和分析的替代框架。尽管提供了计算优势，CA 尚未广泛应用于材料科学和机械工程的框架中，而目前的候选者是该领域的领导者。该提案的主要和长期目标是开发 CA 模型，能够根据表面处理过程和施加的载荷引起的应力和应变不均匀性计算裂纹的萌生和扩展，从而允许开发统计方法。次要目标包括进一步开发实验技术，通过记录各种微观结构和合金疲劳测试期间微观结构的适应情况来校准和验证开发的模型。将研究机械加工、表面喷丸（锤击或喷丸）、渗碳或感应淬火等表面处理，因为它们是候选者研究的一些表面处理。本提案也将涵盖实验验证。测量的规模需要开发原始且精确的技术，这些技术现在可用于进一步的材料研究。 CA 模型收集的统计结果将集成到各种基于微观结构的模型中，以进行疲劳寿命预测。