高拱坝地震损伤破坏的并行计算研究

Research on parallel computing of damage prediction of high arch dams subjected to earthquakes

高拱坝在强震中的损伤破坏对其抗震安全评价具有重要意义,但与之对应的大规模数值模拟需要高效、强大的计算能力的支持,传统的串行计算难以满足,大规模并行计算是解决这一问题的有效途径。利用宏观均质假定基础上考虑混凝土细观不均匀性的拱坝地震损伤破坏模型,在消息传递并行环境下,基于主从编程模式和区域分解法,采用Fortran语言编制了并行计算程序。该程序在4节点微机集群上运行,实现了对某在建拱坝地震损伤破坏过程的数值模拟,计算规模超过百万自由度,获得的破坏形态与模型动力破坏试验符合良好。该程序可再现拱坝的损伤破坏过程,在拱坝的抗震分析中有良好的应用前景。

The prediction of damage process of high arch dams is significant to the effectiveness of aseismic evaluation. However, such numerical simulation requires rigorous computational capacity. Conventional serial computing falls short of that and parallel computing is the ultimate solution to this problem. The parallel finite element code PDPAD was developed for the damage prediction of arch dams utilizing the damage model with inheterogeneity of concrete considered. Developed with language Fortran, the code uses a master/slave mode for programming, domain decomposition method for allocation of tasks, MPI （Message Passing Interface） for communication and solvers from AZTEC library for solution of large-scale equations. Efficiency test showed that the performance of PDPAD was quite satisfactory. The code was employed to study a being-built arch dam on a 4-node PC Cluster, with more than one mil- lion degrees of freedom considered. The obtained damage mode was quite similar to that of shaking table test, indicating that the proposed procedure and parallel code PDPAD has a good potential to simulate seismic damage mode of arch dams. And as stated, parallel computing can be the ultimate method for numerical simulation of such large-scale engineering problems.