CAJ | 학술논문

Munjiza提出的有限元-离散元耦合分析方法（FEDM）是分析岩石破裂过程的一种十分有效的方法。然而，为了克服网格依赖性，需要将岩体剖分成非常细小的三角形单元，且三角形单元之间不共用节点，导致问题的变量数目巨大，计算非常耗时。为了提高计算效率，基于OpenMP(open multi-processing)多核并行技术实现了有限元-离散元法的并行化，克服了并行化过程中存在的数据竞争，实现了并行程序的负载平衡。提出了一套将串行程序并行化的策略，即首先确定串行程序的热点区域，然后尽可能地将热点区域并行化，尽量使用私有变量来规避数据竞争；若各线程间仍存在数据竞争，可采用动态链表数据结构，先将数据存于动态链表中，最后在并行区域外，将存于各个动态链表中的数据进行合并，这样可以规避数据竞争，同时避免了使用临界区或锁，从而提高了程序的并行化效果。开发了并行版本 FDEM 程序，将所提出的方法用于大规模工程问题的求解，最后通过陡崖塌落的算例说明该方法的有效性。
Munjiza제출적유한원-리산원우합분석방법（FEDM）시분석암석파렬과정적일충십분유효적방법。연이，위료극복망격의뢰성，수요장암체부분성비상세소적삼각형단원，차삼각형단원지간불공용절점，도치문제적변량수목거대，계산비상모시。위료제고계산효솔，기우OpenMP(open multi-processing)다핵병행기술실현료유한원-리산원법적병행화，극복료병행화과정중존재적수거경쟁，실현료병행정서적부재평형。제출료일투장천행정서병행화적책략，즉수선학정천행정서적열점구역，연후진가능지장열점구역병행화，진량사용사유변량래규피수거경쟁；약각선정간잉존재수거경쟁，가채용동태련표수거결구，선장수거존우동태련표중，최후재병행구역외，장존우각개동태련표중적수거진행합병，저양가이규피수거경쟁，동시피면료사용림계구혹쇄，종이제고료정서적병행화효과。개발료병행판본 FDEM 정서，장소제출적방법용우대규모공정문제적구해，최후통과두애탑락적산례설명해방법적유효성。
The coupling method of finite-discrete element method(FDEM) by Munjiza is an effective procedure for simulating rock failure. In order to overcome the mesh dependency, it is necessary to partition the rock mass into very small triangular elements;and the elements do not share the nodes, creating a vast number of variables, therefore, the calculation is very time consuming. The method overcomes competition among the existing data in the parallelization and balances loads in a parallel program. A set of strategies for parallelizing serial programs are proposed, determining the hot zones of the serial program, then parallelizing the hot zones as far as possible and using as many private variable as possible to circumvent competition. If there are still data competition among the treads, dynamic lists can be used to store these competitive data. Finally, the data stored in the various dynamic lists are merged outside the parallel zones. Data competition is accordingly avoided with no use of critical section or lock;and the effect of the program parallelization is hence increased. By the proposed method, the parallel version of the FDEM program is developed, which can be used to solve large-scale problem. A numerical example about cliffs collapse shows the effectiveness of the proposed method.