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摘要: 针对球形粒子组成的散体系统，基于离散单元法，将球形粒子离散成弹簧-球单元系统，给出了离散单元的运动方程，建立了离散单元之间的弹性力和接触力的计算模型，并用Mohr -Coulomb型破坏准则判断粒子的破碎。运用上述方法，对圆筒内由脆性材料组成的散体系统在冲击载荷下的挤压破碎过程进行了数值模拟；计算过程中，跟踪散体系统中每个粒子在不同时刻的破碎情况；分析了散体系统冲击破碎过程数值模拟结果的主要影响因素。结果显示：数值模拟过程中需综合考虑计算精度和计算时间之间的平衡；相同的计算条件下，颗粒的初始堆积方式不同，计算得到的散体系统的破碎程度不同。Abstract: Aimed to a granular system composed of spherical particles, the particles were divided into a spring -spherical elements system based on the discrete element method.The calculation models were given for the elastic and contact forces between discrete elements.And the Mohr -Coulomb failure rule was used to estimate the fragmentation of the discrete elements.The above methods were applied to numerically simulate the impact fragmentation process of the granular system composed of brittle material in a cylinder.In the numerical simulations, the fragmentation states of each particle in the granular system at different times were followed.And the main influencing factors were analyzed on the simulated results.The investigations display that in the numerical simulation, it is necessary to consider the balance between computational accuracy and time.And under the same computational conditions, the calculated fragmentation degrees of granular systems will vary with the packing ways of the particles.
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Key words:
- solid mechanics /
- fragmentation /
- discrete element method /
- granules
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