散粒煤对敞车静压力的三维有限元模拟

以C70型敞车和散粒煤为研究对象,根据散粒煤的特性,采用修正的Drucker-Prager准则模拟其塑性屈服行为;根据土力学理论,认为散粒煤各向同性,采用线弹性模型模拟其弹性属性。基于有限元分析软件Abaqus,建立整车三维有限元模型,在车体底面、端墙、侧墙均设置面面接触类型,接触方法选择柔柔接触。利用有限元方法,对敞车车体静侧压力进行有限元模拟,得到静压力的等效应力、位移、侧压力响应结果。结果表明:与常用线性有限元方法计算结果相比,车体端侧墙等效应力较大;将侧压力与库仑土压力理论进行对比,侧压力沿敞车墙高呈非线性分布,且在顶部位置不为零;由于受车体结构的影响,端墙的侧压力值大于侧墙的侧压力值,而接近车体底部位置端墙的侧压力值小于侧墙的侧压力值,端、侧墙侧压力均在车体底部出现压力松弛现象,与试验结果一致。

Theoretical Models of Light Scattering Applied in Sizing Particles in Coal Water Slurry

Advantges and disadvantage of Mie scattering model and Fraunhofer diffraction model are discussed. The result shows that 1) the Fraunhofer diffraction model is simple in design and fast in operation, which is quite suitable for on-line control and 2) the intensity and energy distribution of diffracted light of both the Mie scattering model and the Fraunhofer theoretical model are compared and researched. Feasibility of using the Fraunhofer diffraction model to replace the Mie scattering model in measuring particles in coal water slurry is demonstrated.