颗粒集合体在外力作用下,颗粒间产生复杂的接触力链效应。为了揭示和描述颗粒集合体力链形成、发展过程以及力链分布形态,基于光弹材料受力产生光学条纹图像的原理,研发出能够使颗粒实现双轴加载和双向流动的颗粒光弹试验装置。通过不同工况条件下的颗粒流动光弹试验,初步反映出颗粒集合体流动产生力链的发育过程和分布形态,即经过颗粒集合体的流动其流动口上部会形成一个拱结构,其可以对上部颗粒体进行支撑以保持上部结构的稳定。为研究不同背景条件下颗粒流力链结构和颗粒集合体细观力学行为,特别是颗粒双向可流动性设计为实际工程应用提供了基础试验方法。
Under applied loadings, particle aggregate produces complex effect of contact force chain between particles. In order to elaborate the formation and development of force chains and to describe the distribution and configuration of the force chains,based on the principle of optical stripes in photoelastic material under loading, an experimental equipment is developed that performs photoelastic test on particle aggregates under biaxially loading and bilaterally flowing conditions. Through case studies for different combinations of loading and particle flow conditions, the effect of force chain of particle aggregates in variety of form and distribution has been generally recognized. After the flowing of particle aggregates, an arch structure forms upon the flowing gate, which can support the upper particle aggregates to maintain the stability of the upper structure. The presented work provides a fundamental experiment method for studying force chain structure of particle flow and mesomechanical behavior of particle aggregates under different backgrounds, particularly, the special design which allows particles to flow out from both the bottom and side gates provides convenience for the practical application.