TESTS AND NUMERICAL SIMULATION OF SIDE PRESSURE ON SILO WALLS BY STORAGE MATERIALS
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摘要: 筒仓卸料动态压力是导致仓壁破坏的主要原因,贮料种类是影响动态压力的重要因素。采用大豆、小麦和砂子三种贮料进行筒仓卸料试验,并基于试验建立筒仓卸料颗粒流数值模拟模型。对筒仓卸料过程中不同贮料的动态侧压力和超压系数进行对比研究,探索不同贮料对动态压力的影响规律。结果表明:1)三种贮料的最大超压系数分别为2.27、1.52和1.24,位置在筒仓高度的1/3附近。2)筒仓侧壁的下落速度小于筒仓中部的,这是由于仓壁密集的力链网络抑制仓壁贮料的流动,并导致侧压力增大。3)观察颗粒力链网络,接近仓壁位置接触力集聚,筒仓中部稀疏,呈现动力拱的形式,拱脚的接触力作用于仓壁,这是动态压力增大的主要原因。Abstract: The dynamic pressure of silo discharging is the main cause of silo wall failure, and the type of storage material were is an important factor affecting dynamic pressure. The silo discharging tests were conducted on the silos infilled with three kinds of storage materials: soybean, wheat and sand. Based on the test, a numerical simulation model of grain flow during discharging was established.The dynamic side pressures and overpressure coefficients of different storage materials during discharging process were compared to explore the influence law of different storage materials on dynamic pressure.The results showed that:1) The maximum overpressure coefficients of the three kinds of storage materials were 2.27, 1.52 and 1.24 respectively, located near 1/3 of the silo height. 2) The falling speed of the silo side wall was less than that of the middle part of the silo, because the dense force chain network on the silo wall inhibited the flow of the storage material near the silo wall and led to the increase of side pressure. 3) By observing the particle force chain network, it was found that the contact forces were concentrated near the silo wall, and it was sparse at the middle part of silo, presenting the form of dynamic arch. The contact force of arch foot was used for the silo wall, which was the main reason for the increase of dynamic pressure.
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Key words:
- silo /
- dynamic pressure /
- static pressure /
- force chain network
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