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为克服离散元-二维颗粒流(PFC2D)程序中阻尼参数选取的任意性,通过悬臂梁的剪弯受力(静态问题)和钢球自由下落-碰撞-反弹(动态问题)的PFC2D模拟,明确了PFC2D中局部阻尼和黏性阻尼的定义及适用范围.结果表明:静态问题可采用局部阻尼,以缩短获得稳定解的计算时间;动态问题则需采用有物理意义的局部阻尼或黏性阻尼,由钢球自由下落-碰撞-反弹PFC2D试验可知,钢球的法向黏性阻尼比为ζ=0.16.阻尼所消耗的能量(阻尼能)是一种微观能量,其变化规律反映了阻尼的作用机理,其发挥方式决定了数值模型获得稳定解的计算时间和计算结果的合理性.因此,只有选取合理的阻尼参数,才能获得与理论或实验室试验结果相吻合的颗粒流PFC2D模拟结果.
In order to overcome the arbitrary selection of damping parameters in the discrete element two-dimensional particle flow (PFC2D) program, the PFC2D simulation of cantilever beam bending force (static problem) and free falling-collision-bounce The definition and application scope of local damping and viscous damping in PFC2D are clarified.The results show that the local damping can be used in static problem to shorten the calculation time to obtain stable solution and the dynamic problem needs to use physical damping or viscous damping , The free-falling-crash-bounce PFC2D experiment shows that the normal viscous damping ratio of the steel ball is ζ = 0.16. The energy consumed by damping (damping energy) is a kind of micro energy whose variation reflects the damping The mechanism of action and its mode of operation determine the calculation time and the calculation results of the numerical model are stable. Therefore, only by selecting reasonable damping parameters, we can get the simulation results of particle flow PFC2D consistent with theoretical or laboratory test results.