局部加卸载下立方体阵列接触力残留的细观特性
发布时间：2018-07-31 20:49
【摘要】：基于光弹试验分析立方体阵列在一个分级加卸载周期下力链和颗粒位移的演化过程,结果表明,接触力和颗粒位移在卸载阶段均存在残留,且接触力和颗粒位移的演化特征一致表明,卸载过程中存在一个临界荷载值。通过建立主力链颗粒的串联接触模型,得出残留接触力取决于力链所受侧向摩阻力,包括颗粒间接触摩擦与咬合力。结合光弹条纹解析所得特征颗粒所受接触力,分析加卸载作用下主力链所受摩阻力的演化特征,得出加卸载过程中主力链所受摩阻力与外荷载呈正相关,表明随着外荷载的增大,颗粒体系的内摩擦作用逐渐发挥以抵抗外力;但相同外荷载下,加载和卸载阶段主力链所受摩阻力并不相等,是立方体阵列产生残留接触力的根源。
[Abstract]:Based on photoelastic experiments, the evolution process of force chain and particle displacement of cubic array under a staged loading and unloading period is analyzed. The results show that both contact force and particle displacement are residual in unloading stage. The evolutional characteristics of contact force and particle displacement show that there is a critical load value in the unloading process. By establishing the series contact model of the main chain particles, it is concluded that the residual contact force depends on the lateral friction resistance of the chain, including the contact friction and bite force between the particles. Combined with the contact force of the characteristic particles obtained by photoelastic stripe analysis, the evolution characteristics of the friction resistance of the main chain under the action of loading and unloading are analyzed, and the positive correlation between the friction resistance of the main chain and the external load during the loading and unloading process is obtained. It is shown that with the increase of the external load, the internal friction of the particle system gradually exerts itself to resist the external force, but under the same external load, the frictional resistance of the main chain in the loading and unloading stages is not equal, which is the root of the residual contact force produced by the cube array.
【作者单位】： 同济大学道路与交通工程教育部重点实验室;
【基金】：国家自然科学基金资助项目(41472247,51608384)~~
【分类号】：TU45
，
本文编号：2156787
[Abstract]:Based on photoelastic experiments, the evolution process of force chain and particle displacement of cubic array under a staged loading and unloading period is analyzed. The results show that both contact force and particle displacement are residual in unloading stage. The evolutional characteristics of contact force and particle displacement show that there is a critical load value in the unloading process. By establishing the series contact model of the main chain particles, it is concluded that the residual contact force depends on the lateral friction resistance of the chain, including the contact friction and bite force between the particles. Combined with the contact force of the characteristic particles obtained by photoelastic stripe analysis, the evolution characteristics of the friction resistance of the main chain under the action of loading and unloading are analyzed, and the positive correlation between the friction resistance of the main chain and the external load during the loading and unloading process is obtained. It is shown that with the increase of the external load, the internal friction of the particle system gradually exerts itself to resist the external force, but under the same external load, the frictional resistance of the main chain in the loading and unloading stages is not equal, which is the root of the residual contact force produced by the cube array.
【作者单位】： 同济大学道路与交通工程教育部重点实验室;
【基金】：国家自然科学基金资助项目(41472247,51608384)~~
【分类号】：TU45
，
本文编号：2156787
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