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MD simulation for nanocrystals 总被引:6,自引:0,他引:6
Molecular dynamic (MD) provided anab initio simulation for nano-scale mechanical behavior of materials, provided that the inter-atomic potential is accurately prescribed.
MD is particularly suitable in simulating the formation, the deformation, and the evolution of nanocrystals under a fast strain
rate. To tackle large scale system and nano-seconds time duration, parallel algorithm is desired. The present paper reviews
the recent advances in MD simulation for nanocrystals rithm is desired. The present paper reviews the recent advances in MD
simulation for nanocrstals with attention focused on the applications toward nanomechanics. The examined issues are: formation
of nanocrystalline metals, nanoindentation on nancorystals, fast deformation of nanocrystals, orderdisorder transition, and
nano-particle impact.
The project supported by the National Natural Science Foundation of China (101212202 and 90205023) 相似文献
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Driven by high frequency and multi-directional shot peens, dislocations of various orientations proliferate into the metal,
and accumulate in high density in the surface layer of a shallow depth. Migration, generation and annihilation of dislocations
dictate the evolution of mobile dislocation density. Simulation for the experiment of pure iron under repeated shot peen flux
of 800 times per square millimeter is carried out, and a dislocation density up to 2.17×1011 mm−2 is achieved. Dislocations of such density in the surface layer are shown to be capable of forming nano-grains whose size
is about 10 nm. Molecular dynamics simulation verifies the formation of nano-grained metals at such dislocation density level.
The dislocations are first regrouped to form subcrystallites, then combined to form stable nanocrystallized grains after sufficiently
long time of relaxation.
The project supported by the National Natural Science Foundation of China (10121202) 相似文献
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面对新一轮科技革命和产业变革,培养实践水平与创新能力兼具的工程人才,必须落实到课程改革.本文提出了一种力学创新实践型教学模式,以学生为中心,成果为导向,从知识、能力、价值观三个层次的培养目标出发,通过开设《力学设计与操作》课程实现对教学设计的具体实施.经过七年的持续优化改进迭代,将“学与做”稳固结合,注重理论授课与竞赛促学的反馈优化调整,发展了优质本科生科创团队,教学成果显著,深受学生欢迎.本文是对该课程的介绍、分析与总结,希望对我国“新工科”建设背景下创新型的卓越工程人才课程改革起借鉴作用. 相似文献
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