The critical solid fraction (ϕ_J), which marks the transition between the solid and liquid phases in the jamming diagram, is influenced by several factors. In this study, the dependency of ϕ_J on strain rate and boundary conditions is examined through discrete element method simulations considering a frictionless polydisperse granular system. Different approaches are used to determine ϕ_J. The observed boundary effect is due to the nonuniform solid fraction distribution induced by the clustering of particles close to rigid-wall boundaries at high compression rates. The solid fraction distribution within the sample in the rigid-wall simulations approaches that in the periodic-boundary simulations as the compression rate decreases. With increasing compression rate, the major force transmission network contains fewer mechanically stable particles and a less stable force transmission network. This causes jamming of the granular assembly at a lower solid fraction. These force transmission networks, however, are fragile and disintegrate quickly upon relaxation.

临界固体分数（φ _Ĵ），其标记在干扰图中的固相和液相之间的过渡，是由几个因素的影响。在这项研究中，通过考虑无摩擦多分散颗粒系统的离散元方法模拟，检验了ϕ _J对应变率和边界条件的依赖性。不同的方法被用于确定φ _Ĵ。观察到的边界效应是由于在高压缩率下，由于靠近刚性壁边界的粒子的聚集而导致的固体分数分布不均匀。随着压缩率的降低，刚性壁模拟中样品中的固体分数分布接近周期边界模拟中的固体分数分布。随着压缩率的增加，主力传递网络包含较少的机械稳定颗粒和较不稳定的力传递网络。这导致粒状组件以较低的固体含量阻塞。然而，这些力传递网络是脆弱的，并且在松弛时会迅速分解。