Rongzhuang Song¹, Yinbo Zhu^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.30, No.3, pp. 1-1, 2024, DOI:10.32604/icces.2024.012598

Abstract Kink defects are prevalent in nanocellulose. The existence of diverse kink patterns lacking molecular-scale resolution has caused uncertainty regarding the mechanisms governing the formation of different kinks in nanocellulose, including both reversible and irreversible kinks. The constraints resulting from these limitations often lead to significant confusion in exploring the structure-property relationships of nanocellulose. By integrating AFM experiments with molecular dynamics simulations, we examined the microstructure-dependent kink deformations in nanocellulose (Iβ phase) and the resultant local microstructural damages. In atomic force microscopy images, bent nanofibrils typically display minor curvatures, whereas kinked nanofibrils exhibit pronounced sharp bends,… More >

Jianhui Yang¹, Kai Shen¹, Shoudong Pan², Shuren Wang^3,*, Zhengsheng Zou³

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 243-255, 2022, DOI:10.32604/fdmp.2022.016677 - 16 December 2021

Abstract The large deformation of soft rock tunnel is one of the key problems to be overcome in the tunnel construction stage. In the present study, the deformation mechanism of a representative tunnel and some related countermeasures are investigated using field tests and engineering geological analysis. Owing to the scarce performances of methods based on other criteria such as small pipe spacing, anchor bolt length and steel frame spacing, a new support scheme is implemented and optimized. Results show that shear failure and bedding sliding are produced under high horizontal stress conditions. The low strength of More >

Wen-Jay Lee^1,*, Yu-Chien Lo², Anchen Yang³, Kuanpeng Chen³, Nan-Yow Chen³

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.2, pp. 293-304, 2019, DOI:10.32604/cmes.2019.06620

Abstract Different thickness of amorphous/nanocrystalline multi-layered structure can be used to modulate the strength and ductility of the composite materials. In this work, molecular dynamics simulations were conducted to study the thickness effect of nanocrystalline layer on mechanical properties and deformation behavior of the Cu₆₄Zr₃₆/Cu multi-layer structure. The stress-strain relationship, local stress, local strain, and deformation mechanism are investigated. The results reveal that the change of thickness of the crystalline layer significantly affects the mechanical properties and deformation behavior. As the strain at the elastic region, the amorphous Cu₆₄Zr₃₆ layer dominates the mechanical behavior, leading the fact More >

S.M. Pradhan¹, K.S.Katti¹, D.R. Katti¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.2, pp. 181-201, 2014, DOI:10.3970/cmes.2014.098.181

Abstract Multiscale modeling of collagen fibril is carried out by incorporating the material properties of collagen obtained from steered molecular dynamics into the finite element model of collagen fibril with inclusion of crosslinks. The results indicate that the nonbonded interactions between collagen and mineral contribute to the significant enhancement of the elastic modulus of collagen fibril at all the crosslink densities in both the low strain and high strain regimes. The crosslinks are found to play an important role in the mechanical response of collagen fibril, the enhancement in elastic modulus ranging from 5-11% for various More >

Jin Ma¹, Jay C. Hanan¹, Ranga Komanduri¹, Hongbing Lu²

CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.4, pp. 349-384, 2012, DOI:10.3970/cmes.2012.086.349

Abstract Amorphous metallic foams are an exciting class of materials for an array of high impact absorption applications, the mechanical behavior of which is only beginning to be characterized. To determine mechanical properties, guide processing, and engineer the microstructure for impact absorption, simulation of the mechanical properties is necessary as experimental determination alone can be expensive and time consuming. In this investigation, the material point method (MPM) with C1 continuous shape function is used to simulate the response of a bulk metallic glass (BMG) closed-cell foam (Pd42.5Cu30Ni7.5P20) under compression. The BMG foam was also tested experimentally… More >

Murat Demiral, Anish Roy, Vadim V. Silberschmidt

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.3, pp. 87-88, 2011, DOI:10.3970/icces.2011.017.087

Abstract Industrial applications of Ti-based alloys especially in aerospace, marine and offshore industries have grown significantly over the years primarily due to their high strength, light weight as well as excellent temperature- and corrosion-resistance properties. Since these alloys are hard to machine, there is an obvious demand to develop simulation tools in order to analyze the material's behavior in machining processes, such as a turning, and to optimize process parameters. High levels of strains and strain rates accompanied by generated high temperatures characterize the deformation process in turning. The character of realisation of deformation mechanisms as… More >

H.F. Zhan, Y.T. Gu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.80, No.1, pp. 23-56, 2011, DOI:10.3970/cmes.2011.080.023

Abstract Based on the embedded atom method (EAM) and molecular dynamics (MD) method, in this paper, the tensile deformation properties of Cu nanowires (NWs) with different pre-existing defects, including single surface defects, surface bi-defects and single internal defects, are systematically studied. In-depth deformation mechanisms of NWs with pre-existing defects are also explored. It is found that Young's modulus is insensitive to different pre-existing defects, but yield strength shows an obvious decrease. Defects are observed influencing greatly on NWs' tensile deformation mechanisms, and playing a role of dislocation sources. Besides of the traditional deformation process dominated by More >

Lei Bao^1,2, Christophe Schuman¹, Jean-sébastien Lecomte¹, Marie-Jeanne Philippe¹, Xiang Zhao², Liang Zuo², Claude Esling¹

CMC-Computers, Materials & Continua, Vol.15, No.2, pp. 113-128, 2010, DOI:10.3970/cmc.2010.015.113

Abstract The mechanisms of small plastic deformation of titanium (T40) during cold rolling and channel die compression by means of "interrupted in situ" EBSD orientation measurements were studied. These interrupted EBSD orientation measurements allow to determine the rotation flow field which leads to the development of the crystallographic texture during the plastic deformation. Results show that during rolling, tension twins and compression twins occur and various glide systems are activated, the number of grains being larger with twins than with slip traces. In channel die compression, only tension twins are observed in some grains, whereas slip More >

R. Matsumoto¹, M. Nakagaki¹, A. Nakatani², H. Kitagawa³

CMES-Computer Modeling in Engineering & Sciences, Vol.9, No.1, pp. 75-84, 2005, DOI:10.3970/cmes.2005.009.075

Abstract In this paper, the internal structure-changes around the crack-tip and the pertinent crack growth behavior in an amorphous metal were studied by a molecular dynamics (MD) simulation. In order to perform a large scale calculation, the domain decomposition method was used for parallel calculation. The Finnis-Sinclair potential for$\alpha$-iron was used to describe the interatomic potential. Computed results show that nano-scaled crystalline phase grows around the crack-tip. The distribution of deformation zones and deformation mechanism are significantly altered. While grains are relatively small, they are not deformed, and the most amorphous-crystal interfaces have a large strain More >

R. Matsumoto, M. Nakagaki

CMES-Computer Modeling in Engineering & Sciences, Vol.10, No.3, pp. 187-198, 2005, DOI:10.3970/cmes.2005.010.187

Abstract Large-scale molecular dynamics simulations of tensile deformation of amorphous metals containing a nano-crystalline particle were performed in order to clarify the effects of particle size and crystal volume fraction on the deformation mechanism and strength. It became clear that particle size has very little effect, while crystal volume fraction has a substantial influence. Elastic modulus and flow stress intensify as crystal volume fraction increases. Furthermore, the stress in the crystal phase continues to increase, even after yielding in the amorphous phase. Consequently, work-hardening effects appear, preventing localization of plastic deformation. Thus, the dispersed nano-crystalline particles… More >