人民黄河
人民黃河
인민황하
Yellow River
2015年
11期
110-113
,共4页
离散元模型%动力法%半径逐步放大法%颗粒半径微调法
離散元模型%動力法%半徑逐步放大法%顆粒半徑微調法
리산원모형%동역법%반경축보방대법%과립반경미조법
discrete element model%dynamic method%radius gradually magnifying method%particle radius slightly adjusting method
针对传统动力法建立离散元模型存在的缺点，对其进行了改进。改进后的动力法可以在整个填充区域内随机地投放颗粒，不需要人为指定颗粒投放区域，这样就缩短了后续动力计算的时间。改进动力法建立离散元模型主要包括：根据级配曲线或者指定的半径区间生成初始颗粒半径集合，并将其投放到填充区域内；将投放后的颗粒导入PFC2D进行计算。在PFC2D计算过程中，为了避免颗粒飞到填充区域外，在初始计算阶段将颗粒半径缩小一半，后续采用颗粒半径逐步放大法将颗粒半径恢复为初始值。某些情况下在移除辅助建模边界后，为了避免颗粒出现飞溢现象，采用颗粒半径微调法逐步减小颗粒间及颗粒与边界之间的接触边界力。以某边坡为例，采用改进后的动力法快速正确地建立其离散元模型，验证了该方法的正确性。
針對傳統動力法建立離散元模型存在的缺點，對其進行瞭改進。改進後的動力法可以在整箇填充區域內隨機地投放顆粒，不需要人為指定顆粒投放區域，這樣就縮短瞭後續動力計算的時間。改進動力法建立離散元模型主要包括：根據級配麯線或者指定的半徑區間生成初始顆粒半徑集閤，併將其投放到填充區域內；將投放後的顆粒導入PFC2D進行計算。在PFC2D計算過程中，為瞭避免顆粒飛到填充區域外，在初始計算階段將顆粒半徑縮小一半，後續採用顆粒半徑逐步放大法將顆粒半徑恢複為初始值。某些情況下在移除輔助建模邊界後，為瞭避免顆粒齣現飛溢現象，採用顆粒半徑微調法逐步減小顆粒間及顆粒與邊界之間的接觸邊界力。以某邊坡為例，採用改進後的動力法快速正確地建立其離散元模型，驗證瞭該方法的正確性。
침대전통동역법건립리산원모형존재적결점，대기진행료개진。개진후적동역법가이재정개전충구역내수궤지투방과립，불수요인위지정과립투방구역，저양취축단료후속동력계산적시간。개진동역법건립리산원모형주요포괄：근거급배곡선혹자지정적반경구간생성초시과립반경집합，병장기투방도전충구역내；장투방후적과립도입PFC2D진행계산。재PFC2D계산과정중，위료피면과립비도전충구역외，재초시계산계단장과립반경축소일반，후속채용과립반경축보방대법장과립반경회복위초시치。모사정황하재이제보조건모변계후，위료피면과립출현비일현상，채용과립반경미조법축보감소과립간급과립여변계지간적접촉변계력。이모변파위례，채용개진후적동역법쾌속정학지건립기리산원모형，험증료해방법적정학성。
Aimed at the existing shortcomings of the traditional technique in the generation of discrete element model, this paper proposed a modified method. The novel method could place the particles in the whole filling region and reduce the dynamic computational time afterward without the restriction of certain area, which could short the subsequent dynamic calculation time. This modified method mainly contained two steps:1) generating the particles according to the gradation curve or specified radius interval were placed in the whole filled areas randomly;2) starting the particles into PFC2D for calculation. During the calculation in PFC2D, in order to avoid the defect of traditional technique that the particle often moved outside of the region, the particles halve their sizes at the beginning of computation and the radius of each particle magnifies gradually to the origin. Ensuring that the particle share could not fly out after the removal of auxiliary boundary, the radii of particles were adjusted slightly to reduce the contact force. Taking a slope as an example, the discrete element model was generated accurately and fast which verified the correctness of this method.
