发表机构
Tokyo Metropolitan University（东京都立大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
通过混合黏性与非黏性颗粒控制键数，发现失效循环次数随混合比平方指数增长，而杨氏模量几乎不变，表明键数是耐久性的关键控制参数。
AI 中文摘要
黏性颗粒材料的机械稳定性不仅取决于单个颗粒间键的强度，还取决于形成承载网络的键的数量。然而，这两种效应在实验上难以分离，因为常规控制参数（如液体含量）通常会同时改变两者。这里，我们使用由黏性和非黏性颗粒组成的混合颗粒系统，在保持键强度近似不变的同时控制黏性键数。我们研究了重复振动下的失效寿命，发现失效循环次数$N_f$强烈依赖于混合比$\alpha$。在随机混合的平均场图像中，黏性接触的比例随$\alpha^2$变化，而$N_f$随$\alpha^2$近似指数增长。相反，尽管寿命随振动强度$G$的增加而趋于减少，但在当前实验范围内，其对$G$的依赖性相对较弱。值得注意的是，尽管在刚性阈值以上杨氏模量几乎不依赖于$\alpha$，寿命却继续随$\alpha$强烈增加。这表明机械刚性和对重复扰动的耐久性对黏性网络表现出不同的依赖性。这些结果确定了键数是控制黏性颗粒材料耐久性的关键参数。
英文摘要
Cohesive granular materials derive their mechanical stability not only from the strength of individual interparticle bonds but also from the number of bonds forming the load-bearing network. However, these two effects are difficult to separate experimentally because conventional control parameters, such as liquid content, generally alter both simultaneously. Here, we use a mixed granular system composed of cohesive and noncohesive grains to control the cohesive bond number while keeping the bond strength approximately unchanged. We investigate the failure lifetime under repeated vibration and find that the number of cycles to failure, $N_f$, depends strongly on the mixing ratio $α$. In a mean-field picture of random mixing, the fraction of cohesive contacts scales as $α^2$, and $N_f$ increases approximately exponentially with $α^2$. By contrast, although the lifetime tends to decrease with increasing vibration intensity $G$, its dependence on $G$ is comparatively weak over the present experimental range. Remarkably, although the Young's modulus is nearly independent of $α$ above the rigidity threshold, the lifetime continues to increase strongly with $α$. This demonstrates that mechanical rigidity and durability against repeated perturbations exhibit distinct dependences on the cohesive network. These results identify bond number as a key control parameter for the durability of cohesive granular materials.
Commentspreprint, 4 figures. Revised Figs. 3 and 4 and the corresponding analysis. The revised manuscript emphasizes the strong nonlinear dependence of the failure lifetime on the cohesive-contact fraction, while the dependence on vibration intensity is found to be comparatively weak over the present experimental range
