3D Printed Particle Analogs for Coarse-grained Soils: Interpretation Framework

用于粗粒土壤的 3D 打印颗粒类似物：解释框架

• 批准号: 1735732
• 负责人: Alejandro Martinez
• 金额: $ 14.96万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2020-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1735732&HistoricalAwards=false
• 关键词: 3D; Printed; Particle; Analogs; Coarse

This project concerns the utilization of 3D printed particle analogs for the fundamental study of coarse-grained soil behavior. These synthetic analogs will address the pervasive challenge in geotechnical engineering caused by the fact that soils are natural materials whose properties are defined by their geologic history, and whose behavior depends on dozens of variables, including particle morphology and size, gradation, and soil state. Development of an interpretation framework, consisting of normalization of the compression and shear responses based on the stiffness of the particles constituent material stiffness, will allow for quantitative study of the response of soils comprised of different materials. It will also allow for validation of results from numerical simulations (e.g. Discrete Element Modeling, DEM). This research: (i) provides the ability to systematically and independently control particle properties of soil analogs, which can transform current research capabilities to study aspects of soil behavior that are important for many applications, such as seepage, pollutant transport, bacterial and fungal growth, erosion, bearing capacity, interface friction, and earth pressures, (ii) facilitates the trans-disciplinary transfer of knowledge among researchers from different disciplines within engineering and the sciences, such as chemical, mechanical and material science engineering and physics, who investigate phenomena in different granular materials such as soils, powders, and grains, (iii) promotes use of 3D printing in research to transform current experimental research techniques within geotechnical engineering, and (iv) increases the involvement of Hispanic students through the entire educational track by training teachers from local middle schools and providing research opportunities to undergraduate students. Qualitative understanding of soil behavior has been achieved by many researchers through experiments on different soils or soil analogs, Discrete Element Modeling (DEM) simulations, or advanced imaging techniques. The two major barriers that have deterred the construction of quantitative understanding using these tools are: (i) the inability of current experimental methods to systematically change one characteristic of natural soil particles, while keeping the others unchanged (affecting interpretation of studies on natural soils), and (ii) the lack of a framework that allows for study of behaviors independently from differences in constituent material properties (affecting interpretation of studies on soil analogs). The hypothesis of this research project is that the response of 3D printed soil analogs can provide direct and quantitative understanding of the response of natural soils. The effects of particle contact deformation are quantified in particle- and element-scale 1D compression tests, and the coupled effect of particle contact and soil skeleton deformation are characterized in triaxial compression shear tests. These experimental insights, in combination with a stiffness-based normalization scheme that accounts for differences in constituent material properties, comprise a framework that allows for direct comparison of the response of natural and analog soils that is only influenced by particle characteristics and soil state. The developed 3D printed soil analogs and interpretation framework will allow for systematic and independent prescription of particle shape, surface roughness, and size for the detailed study of the behavior of coarse-grained soils. This will advance the understanding of the influence of particle constituent material stiffness on the compression and shear response of soils at the particle- and element-scales, and incorporate the effect of particle stiffness on the framework of critical state soil mechanics.

该项目涉及利用3D打印颗粒类似物进行粗粒土行为的基础研究。 这些合成类似物将解决岩土工程中普遍存在的挑战，因为土壤是天然材料，其性质由其地质历史定义，其行为取决于数十个变量，包括颗粒形态和大小，级配和土壤状态。 解释框架的开发，包括基于颗粒组成材料刚度的压缩和剪切响应的归一化，将允许对由不同材料组成的土壤的响应进行定量研究。 它还将允许验证数值模拟（例如离散元建模，DEM）的结果。 这项研究：（i）提供系统地和独立地控制土壤类似物的颗粒性质的能力，这可以改变当前的研究能力，以研究对许多应用重要的土壤行为的方面，例如渗流、污染物运输、细菌和真菌生长、侵蚀、承载能力、界面摩擦和土压力，（ii）促进工程和科学领域内不同学科的研究人员之间的跨学科知识转移，如化学、机械和材料科学工程和物理学，研究不同颗粒材料（如土壤、粉末和颗粒）中的现象，（iii）促进3D打印在研究中的使用，以改变岩土工程中当前的实验研究技术，以及（iv）通过培训当地中学的教师和为本科生提供研究机会，增加西班牙裔学生在整个教育轨道上的参与。许多研究人员通过对不同土壤或土壤类似物的实验、离散元模型（DEM）模拟或先进的成像技术，对土壤行为有了定性的了解。 阻碍使用这些工具构建定量理解的两个主要障碍是：（i）目前的实验方法无法系统地改变天然土壤颗粒的一个特性，同时保持其他特性不变（影响对自然土壤研究的解释），以及（ii）缺乏一个框架，该框架允许独立于组成材料特性的差异来研究行为（影响对土壤类似物研究的解释）。 该研究项目的假设是，3D打印土壤类似物的响应可以提供对天然土壤响应的直接和定量的理解。 颗粒接触变形的影响在颗粒和元素尺度的一维压缩试验中进行了量化，颗粒接触和土骨架变形的耦合效应在三轴压缩剪切试验中进行了表征。这些实验的见解，结合刚度为基础的归一化方案，占组成材料特性的差异，包括一个框架，允许直接比较自然和模拟土壤的反应，只受颗粒特性和土壤状态。开发的3D打印土壤类似物和解释框架将允许系统和独立地规定颗粒形状，表面粗糙度和尺寸，以详细研究粗粒土壤的行为。 这将促进颗粒组成材料刚度对颗粒和单元尺度上的土壤的压缩和剪切响应的影响的理解，并将颗粒刚度的影响纳入临界状态土壤力学的框架。

项目成果

https://doi.org/10.1061/9780784482803.017

https://doi.org/10.1061/9780784482803.017

• DOI: 10.1061/9780784482803.017
• 发表时间: 2020
• 期刊: GeoCongress 2020
• 作者: Ahmed, Sharif A;Martinez, Alejandro
• 通讯作者: Martinez, Alejandro

Triaxial compression behavior of 3D printed and natural sands

• DOI: 10.1007/s10035-021-01143-0
• 发表时间: 2021-11-01
• 期刊: GRANULAR MATTER
• 影响因子: 2.4
• 作者: Ahmed, Sheikh Sharif;Martinez, Alejandro
• 通讯作者: Martinez, Alejandro

Framework for Modeling Coarse-Grained Soil Behavior Using 3D Printed Soil Analogs

使用 3D 打印土壤类似物模拟粗粒土壤行为的框架

• 发表时间: 2018
• 期刊: IS Atlante from Micro to Macro
• 作者: Martinez, A;Ahmed, S.S.
• 通讯作者: Ahmed, S.S.

Effects of Particle Shape on the Shear Wave Velocity and Shear Modulus of 3D Printed Sand Analogs

• DOI: 10.5802/ogeo.9
• 发表时间: 2022-03
• 期刊: Open Geomechanics
• 作者: S. S. Ahmed-S.;Alejandro Martinez

Modeling the mechanical behavior of coarse-grained soil using additive manufactured particle analogs

• DOI: 10.1007/s11440-020-01007-6
• 发表时间: 2020-06-28
• 期刊: ACTA GEOTECHNICA
• 影响因子: 5.7
• 作者: Ahmed, Sheikh Sharif;Martinez, Alejandro
• 通讯作者: Martinez, Alejandro