On the tensile strength of soil grains in Hertzian response
On the tensile strength of soil grains in Hertzian response
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DOI：
10.1051/epjconf/201714007001
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发表时间：
2017-07
期刊：
影响因子：
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通讯作者：
S. Nadimi;Joana Fonseca
中科院分区：
文献类型：
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作者：
S. Nadimi;Joana Fonseca
土颗粒的破裂起始受其抗拉能力控制。尽管抗拉强度很重要，但由于测量困难，它经常被忽视。本文通过实验和数值模拟研究了抗拉强度对单个土颗粒赫兹响应的影响。赫兹理论常用于数值模拟中，以呈现在法向载荷下纯弹性颗粒的接触本构行为。这种法向力：位移来自于晶粒内部的应力分布和集中。当应力达到抗拉能力时，裂纹开始产生。进行了一系列数值试验，以确定赫兹响应的灵敏度选定的抗拉强度作为输入数据。在有限元-离散元组合框架中，采用了球形颗粒的弹性损伤本构模型。通过考虑以前的理论工作丰富了结果的解释。此外，还对波斯湾的莱顿·布扎德硅砂和粗碳酸盐砂的球形玻璃珠和颗粒进行了系统的试验研究。初步结果表明，较低的抗拉强度导致在正常载荷下较软的响应。碳酸盐砂的响应范围更广，据信与组成颗粒的生物碎屑来源相关的大量颗粒形状有关。
The breakage initiation of soil grains is controlled by its tensile capacity. Despite the importance of tensile strength, it is often disregarded due to difficulties in measurement. This paper presents an experimental and numerical investigation on the effect of tensile strength on Hertzian response of a single soil grain. Hertz theory is commonly used in numerical simulation to present the contact constitutive behaviour of a purely elastic grain under normal loading. This normal force:displacement comes from stress distribution and concentration inside the grain. When the stress reaches the tensile capacity, a crack initiates. A series of numerical tests have been conducted to determine the sensitivity of Hertzian response to the selected tensile strength used as an input data. An elastic-damage constitutive model has been employed for spherical grains in a combined finite-discrete element framework. The interpretation of results was enriched by considering previous theoretical work. In addition, systematic experimental tests have been carried out on both spherical glass beads and grains of two different sands, i.e. Leighton Buzzard silica sand and coarse carbonate sand from Persian Gulf. The preliminary results suggest that lower tensile strength leads to a softer response under normal loading. The wider range of responses obtained for the carbonate sand, are believed to be related to the large variety of grain shape associated with bioclastic origin of the constituent grains.