Numerical Simulation of the Contact Behaviour of Granular Matters with Heterogeneous surfaces

颗粒材料是指一类由单个颗粒组成的天然和合成材料，这些颗粒在受到载荷时相互作用。这些材料的表现与通常的固体不同，表现出许多显著的特征，如膨胀性、各向异性、压力依赖性、密度依赖性和非线性弹性。颗粒材料的力学行为是许多领域长期感兴趣的主题，具有科学魅力和实际重要性，如高价值制造，纳米技术，制药，岩土工程等。颗粒材料的整体响应高度依赖于组成颗粒的堆积模式和相互作用，而这又与颗粒的特性密切相关。基于最近对颗粒材料接触行为的理解，我们知道表面不规则性在颗粒之间的能量和力的传递中起着重要的作用，并决定了这种材料的宏观行为。学术界和工业界迫切需要新的模型，可以在计算力时考虑表面粗糙度，从而预测颗粒物质的性能。利兹大学是解决这一突破性问题的关键所在，因为它拥有两个世界级的“摩擦学”和“颗粒技术”研究所，将表面粗糙度表征和接触建模与颗粒流和表征结合在一起。这个项目将是一个很好的机会，让一个高水平的学生参与到这两个研究所的联合项目中。该项目将是一个计算项目，利用功能表面研究所最先进的建模能力和工业上使用的商业模型，该模型基于化学与过程工程学院提供的离散元素方法。学生有机会在一个大财团（制造使用先进粉末工艺，https://mapp.ac.uk/）中与许多学者和行业合作，同时也是集成摩擦学博士培训中心https://www.it-cdt.co.uk/的一部分。该学生还将成为世界领先的功能表面研究所的一员，与约70名博士生和25名PDRAs一起促进该项目的传播。

Granular materials refer to a class of natural and synthetic materials consisting of individual particles that interact with each other when subjected to loading. These materials behave differently from usual solids and exhibit many salient features such as dilatancy, anisotropy, pressure dependence, density dependence, and nonlinear elasticity. The mechanical behaviour of granular materials is a subject of long-standing interest in many fields, with both scientific fascination and practical importance such as high value manufacturing, nano-technology, pharmaceuticals, geotechnics etc. The overall response of a granular materials is highly dependent on the packing patterns and interactions of the constituent particles which are, further, closely related to the characteristics of the particles. Based on recent advancements in the understanding of contact behaviour in granular materials, it is known that surface irregularities play significant roles in the transfer of energy and forces between particles and dictate macroscopic behaviours of such materials. Academic and industrial community desperately need new models that can accommodate surface roughness in the calculations of forces and therefore predict the performance of granular matter. Leeds University is a pivotal place to tackle this ground breaking issue since it has two world class institutes of "Tribology" and "Particle technology" to get together the top expertise in surface roughness characterisation and contact modelling with particle flow and characterisation. This project will be a great opportunity for a high class student to be involved in a joint project between these two institutes. The project will be a computational project utilising the state-of-the-art modelling capability at the institute of Functional Surfaces and the industrially used commercial model based on Discrete Element Method available in the School of Chemical and Process Engineering. There is an opportunity for the student to collaborate with a number of academics and industries in a big consortium (Manufacture using Advanced Powder Processes, https://mapp.ac.uk/ ) and also being part of a Centre for Doctoral training in Integrated Tribology https://www.it-cdt.co.uk/. The student will also be part of the world-leading Institute of Functional Surfaces working along with about 70 PhD students and 25 PDRAs to facilitate the dissemination of the project.