Elasto-plastic deformation mechanisms of thermoset glassy polymers depending on the structural characteristic of hardener: A molecular dynamics study

2017 ◽  
Author(s):  
Hyungbum Park ◽  
Byungjo Kim ◽  
Joonmyung Choi ◽  
Maenghyo Cho
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Structural Characteristic ◽  
Glassy Polymers ◽  
Deformation Mechanisms

scholarly journals The Plastic Deformation Mechanisms of hcp Single Crystals with Different Orientations: Molecular Dynamics Simulations

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 733
Author(s):  
Zhi-Chao Ma ◽  
Xiao-Zhi Tang ◽  
Yong Mao ◽  
Ya-Fang Guo
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Phase Transformation ◽  
Molecular Dynamics Simulations ◽  
Single Crystals ◽  
Deformation Mechanisms ◽  
Shear Stresses ◽  
Affecting Factors ◽  
Fcc Phase ◽  
Dynamics Simulations

The deformation mechanisms of Mg, Zr, and Ti single crystals with different orientations are systematically studied by using molecular dynamics simulations. The affecting factors for the plasticity of hexagonal close-packed (hcp) metals are investigated. The results show that the basal <a> dislocation, prismatic <a> dislocation, and pyramidal <c + a> dislocation are activated in Mg, Zr, and Ti single crystals. The prior slip system is determined by the combined effect of the Schmid factor and the critical resolved shear stresses (CRSS). Twinning plays a crucial role during plastic deformation since basal and prismatic slips are limited. The 101¯2 twinning is popularly observed in Mg, Zr, and Ti due to its low CRSS. The 101¯1 twin appears in Mg and Ti, but not in Zr because of the high CRSS. The stress-induced hcp-fcc phase transformation occurs in Ti, which is achieved by successive glide of Shockley partial dislocations on basal planes. More types of plastic deformation mechanisms (including the cross-slip, double twins, and hcp-fcc phase transformation) are activated in Ti than in Mg and Zr. Multiple deformation mechanisms coordinate with each other, resulting in the higher strength and good ductility of Ti. The simulation results agree well with the related experimental observation.

A comparative study of plastic deformation mechanisms in room-temperature and cryogenically deformed magnesium alloy AZ31

2021 ◽  
Vol 807 ◽  
pp. 140821
Author(s):  
Kai Zhang ◽  
Zhutao Shao ◽  
Christopher S. Daniel ◽  
Mark Turski ◽  
Catalin Pruncu ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Magnesium Alloy ◽  
Comparative Study ◽  
Room Temperature ◽  
Deformation Mechanisms ◽  
Alloy Az31 ◽  
Magnesium Alloy Az31

Hard and Soft: Principles of Polyner-Impregnated Concrete Using Elastomers

2013 ◽  
Vol 687 ◽  
pp. 118-123 ◽  
Author(s):  
Oliver Weichold ◽  
Udo Antons
Keyword(s):  
Plastic Deformation ◽  
Fracture Mechanics ◽  
Brittle Failure ◽  
Elastic Moduli ◽  
Domain Size ◽  
Glassy Polymers ◽  
Crack Deflection ◽  
Micro Cracks ◽  
Concrete Interface ◽  
Crystalline Matrix

The effect of incorporating elastomeric domains in concrete is described from the point of fracture mechanics. Concrete is subject to brittle failure, since cracks propagate at an enormous speed in the crystalline matrix. However, micro cracks are attracted to volume elements with lower elastic moduli such as elastomeric domains. Cracks that encounter the concrete-elastomer interface are stopped since energy is dissipated by plastic deformation of and/or crack deflection by the elastomer. The domain size and the distribution of the elastomer as well as, and properties of the elastomer-concrete interface are crucial parameters. Such a combination differs substantially from previously prepared polymer-impregnated concretes, in which only glassy polymers were used.

Investigations on Microstructure Evolution and Deformation Behavior of Aged and Ultrafine Grained Al-Zn-Mg Alloy Subjected to Severe Plastic Deformation

2010 ◽  
Vol 667-669 ◽  
pp. 253-258
Author(s):  
Wei Ping Hu ◽  
Si Yuan Zhang ◽  
Xiao Yu He ◽  
Zhen Yang Liu ◽  
Rolf Berghammer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Severe Plastic Deformation ◽  
Microstructure Evolution ◽  
Deformation Behavior ◽  
Deformation Mechanisms ◽  
Mg Alloy ◽  
Ultrafine Grained

An aged Al-5Zn-1.6Mg alloy with fine η' precipitates was grain refined to ~100 nm grain size by severe plastic deformation (SPD). Microstructure evolution during SPD and mechanical behaviour after SPD of the alloy were characterized by electron microscopy and tensile, compression as well as nanoindentation tests. The influence of η' precipitates on microstructure and mechanical properties of ultrafine grained Al-Zn-Mg alloy is discussed with respect to their effect on dislocation configurations and deformation mechanisms during processing of the alloy.

scholarly journals Molecular Dynamics Simulation of Crack Propagation in Single-Crystal Aluminum Plate with Central Cracks

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Jun Ding ◽  
Lu-sheng Wang ◽  
Kun Song ◽  
Bo Liu ◽  
Xia Huang
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Crack Propagation ◽  
Strain Rate ◽  
Single Crystal ◽  
Crack Length ◽  
Crack Growth ◽  
Plastic Yield ◽  
Model Size ◽  
Dislocation Multiplication

The crack propagation process in single-crystal aluminum plate (SCAP) with central cracks under tensile load was simulated by molecular dynamics method. Further, the effects of model size, crack length, temperature, and strain rate on strength of SCAP and crack growth were comprehensively investigated. The results showed that, with the increase of the model size, crack length, and strain rate, the plastic yield point of SCAP occurred in advance, the limit stress of plastic yield decreased, and the plastic deformability of material increased, but the temperature had less effect and sensitivity on the strength and crack propagation of SCAP. The model size affected the plastic deformation and crack growth of the material. Specifically, at small scale, the plastic deformation and crack propagation in SCAP are mainly affected through dislocation multiplication and slip. However, the plastic deformation and crack propagation are obviously affected by dislocation multiplication and twinning in larger scale.

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