Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Fast parallel algorithms for short-range molecular dynamics

Small but strong: A review of the mechanical properties of carbon nanotube–polymer composites

Carbon nanotube–polymer composites: Chemistry, processing, mechanical and electrical properties

Owing to their unique mechanical properties, carbon nanotubes are considered to be ideal candidates for polymer reinforcement. However, a large amount of work must be done in order to realize their full potential. Effective processing of nanotubes and polymers to fabricate new ultra-strong composite materials is still a great challenge. This Review explores the progress that has already been made in the area of mechanical reinforcement of polymers using carbon nanotubes. First, the mechanical properties of carbon nanotubes and the system requirements to maximize reinforcement are discussed. Then, main methods described in the literature to produce and process polymer–nanotube composites are considered and analyzed. After that, mechanical properties of various nanotube–polymer composites prepared by different techniques are critically analyzed and compared. Finally, remaining problems, the achievements so far, and the research that needs to be done in the future are discussed.

Mechanical Reinforcement of Polymers Using Carbon Nanotubes

This review summarises the research work carried out in the field of carbon nanotube (CNT) metal matrix composites (MMCs). Much research has been undertaken in utilising CNTs as reinforcement for composite material. However, CNT-reinforced MMCs have received the least attention. These composites are being projected for use in structural applications for their high specific strength as well as functional materials for their exciting thermal and electrical characteristics. The present review focuses on the critical issues of CNT-reinforced MMCs that include processing techniques, nanotube dispersion, interface, strengthening mechanisms and mechanical properties. Processing techniques used for synthesis of the composites have been critically reviewed with an objective to achieve homogeneous distribution of carbon nanotubes in the matrix. The mechanical property improvements achieved by addition of CNTs in various metal matrix systems are summarised. The factors determining strengthening achieved by CNT reinforcement are elucidated as are the structural and chemical stability of CNTs in different metal matrixes and the importance of the CNT/metal interface has been reviewed. The importance of CNT dispersion and its quantification is highlighted. Carbon nanotube reinforced MMCs as functional materials are summarised. Future work that needs attention is addressed.

Carbon nanotube reinforced metal matrix composites - a review

Improved processing of carbon nanotube/magnesium alloy composites

https://hal.archives-ouvertes.fr/hal-00696564/document

CNT reinforced light metal composites produced by melt stirring and by high pressure die casting

Strengthening of carbon nanotube/epoxy resin composites was achieved by adding a small amount of copolymer (0.03 wt% of epoxy resin) as a dispersant. Tensile testing was used to measure mechanical properties. Young's modulus and fracture stress of the carbon nanotube composites with the copolymer were found to be about 50% higher than for the pure epoxy resin, and about 20% higher than for the composite without the dispersing agent. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Qianqian Li

Papers

Improved processing of carbon nanotube/magnesium alloy composites

CNT reinforced light metal composites produced by melt stirring and by high pressure die casting

Carbon nanotube/epoxy resin composites using a block copolymer as a dispersing agent

Corrosion behaviour of multiwall carbon nanotube/magnesium composites in 3.5% NaCl

Mapping carbon nanotube orientation by fast fourier transform of scanning electron micrographs