并行MD优化算法与纳米晶体力学模拟

为发展可适用于纳米晶体力学模拟的高效率并行算法,构建了从晶体生成、计算到显示的分子动力学(MD)模拟系统.MD算法基于经典的对势和多体势上的Verlet算法,并行格式基于Linked-Cell-List方案,并针对特定的研究模型进行了各计算层次的优化.构建了交互式显示和控制子系统,可提供显示原子图像和属性的高质量图形输出.利用此模拟系统对纳米晶体进行了拉伸大变形和压痕模拟,结果表明: 在高速加载率下,堆垛层错(偏位错)的迸发、传播及其在晶界处的终止是纳米晶体变形的主要机制.

Optimized parallel MD algorithm for simulation of the mechanics of nanocrystals

A scalable molecular dynamics (MD) algorithm was developed to simulate the deformation of nanocrystals. The MD algorithm is capable of generating multiple crystals. The MD formulation was based on classical (pair and multi-body) potentials and the Verlet algorithm. Parallel computations used the Linked-Cell-List method, with optimizations in different method and application levels to obtain scalability. The visualization provided interactive animation and control. The atoms were painted in high quality graphics according to their properties. The algorithm was utilized to simulate the tension and indentation of nanocrystals with finite deformations. The results indicate that bursts, propagation of stacking faults and grain boundaries play decisive roles in ultra-high speed deformation of nanocrystals.