Modeling the mechanical behavior of coarse-grained soil using additive manufactured particle analogs
Modeling the mechanical behavior of coarse-grained soil using additive manufactured particle analogs
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DOI：
10.1007/s11440-020-01007-6
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发表时间：
2020-06-28
期刊：
影响因子：
5.7
通讯作者：
Martinez, Alejandro
中科院分区：
文献类型：
--
作者：
Ahmed, Sheikh Sharif;Martinez, Alejandro
系统地研究单个颗粒特性，如形状、大小、表面粗糙度和组成材料的刚度，对粗颗粒土壤的行为的影响，需要对其他颗粒特性进行仔细的控制。在对天然土壤的研究中，实现这种控制是一个普遍的挑战。现代增材制造（AM）技术的快速发展提供了创建独立控制颗粒大小和形状的模拟颗粒的能力。这项工作评估了立体光刻（SLA）和多射流技术产生模拟颗粒的可行性，这些模拟颗粒可以模拟粗颗粒土壤的力学行为。AM通过对天然圆形和角状沙粒进行三维x射线CT扫描，生成等大小的球体和模拟沙粒。研究了AM颗粒的单轴压缩、测压和剪切波传输特性，并与玻璃球、钢球和天然圆形和角砂粒进行了比较。结果表明，增材制造可以成功地再现天然粗砂颗粒的形状。发现微凸点的变形会影响复合喷射AM颗粒的接触响应，从而影响颗粒间单轴压缩和测径压缩响应。SLA AM颗粒的接触响应更接近于玻璃球的接触响应。两种AM颗粒类型均表现出剪切波速和剪切模量对平均有效应力的依赖关系，这与天然砂一致。
Systematic investigation of the effects of individual particle properties, such as shape, size, surface roughness, and constituent materials stiffness, on the behavior of coarse-grained soils requires careful control over the other particle properties. Achieving this control is a pervasive challenge in investigations with naturally occurring soils. The rapid advance of modern additive manufacturing (AM) technology provides the ability to create analog particles with independent control over particle size and shape. This work evaluates the feasibility of the stereolithography (SLA) and polyjet technologies to generate analog particles that can model the mechanical behavior of coarse-grained soils. AM is used to generate equal-sized spheres and analog sand particles from 3D X-ray CT scans of natural rounded and angular sand particles. The uniaxial inter-particle compression, oedometer compression, and shear wave transmission behaviors of the AM particles are investigated and compared to those of glass and steel spheres and natural rounded and angular sand particles. The results indicate that AM can successfully reproduce the shape of natural coarse sand particles. The deformation of micro-asperities was found to influence the contact response of the polyjet AM particles, thus affecting their inter-particle uniaxial compression and oedometer compression response. The contact response of the SLA AM particles was closer to that of glass spheres. Both AM particle types exhibit a dependency of shear wave velocity and shear modulus on mean effective stress that is consistent with that of natural sands.