基于离散元法的料仓稻种颗粒沉降特性与力链演化分析OA

[Objective]To reveal the movement law and force chain characteristic evolution mechanism of stored rice seed particles during the settlement process in a silo.[Methods]With the Xinliangyou 98 hybrid rice seeds as the research object,a"rice seed-silo"simulation model was established using the discrete element method(DEM)to simulate the effect of different settlement heights,grain pile components,and mass flow rates on the fundamental parameters of rice seed settlement motion.A quantitative analysis method for the force chain characteristics of the rice seed population in the silo was proposed to investigate the influence patterns of different mass flow rates and settlement heights on force chain characteristics,thereby establishing the relationship between the settlement characteristics of rice seeds and the force chain behavior.[Results]During the descent of rice seeds,the acceleration gradually decreased to zero,and the falling velocity approached a stable value of 11.34 m/s.It took 4.13 seconds to reach a uniform velocity state,corresponding to a settlement height of 28.44 m.Under the same initial conditions,different grain pile components exhibited significant differences in their final velocities.Among them,stones reached the highest velocity of 16.8 m/s,and intact rice seeds attained 11.34 m/s.One-half,one-quarter,one-eighth incomplete particles and fine debris decelerated to 9.9 m/s,8.3 m/s,6.6 m/s,and 1.1 m/s,respectively,intensifying the interactions between different populations.As the mass flow rate increased from 100 kg/s to 250 kg/s,the number of force chains increased,and the force chain orientation coefficient decreased from 0.28 to 0.11.Meanwhile,the bearing non-uniformity of the force chains within the population gradually diminished,indicating a more even distribution of contact forces along the force chains.Lower mass flow rates result in a localized concentration of force chain bearing.[Conclusion]With the increase in the mass flow rate of the rice seed population,the force chain unit flexure gradually decreases,indicating that the increase in mass flow rate gradually alleviates the flexure of force chains.The mass flow rate has a significant influence on the evolution of force chain characteristics.