Shichao Ma^{1, 2, *}, Xin Ning^{1, 2, *}, Liang Wang³

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.1, pp. 49-59, 2020, DOI:10.32604/cmes.2020.06911

Abstract Friction systems are a kind of typical non-linear dynamical systems in the actual engineering and often generate abundant dynamics phenomena. Because of non-smooth characteristics, it is difficult to handle these systems by conventional analysis methods directly. At the same time, random perturbation often affects friction systems and makes these systems more complicated. In this context, we investigate the steady-state stochastic responses and stochastic P-bifurcation of friction systems under random excitations in this paper. And in order to retain the non-smooth of friction system, the generalized cell mapping (GCM) method is first used to the original… More >

Haiyang Ding¹, Xiaohua Yang¹, Lina Xu¹, Mei Li¹, Shouhai Li¹, Jianling Xia^1,*

Journal of Renewable Materials, Vol.7, No.12, pp. 1391-1401, 2019, DOI:10.32604/jrm.2019.07207

Abstract A water-soluble lubricant additive (RSOPE) was prepared by esterification reaction using fatty acid from rubber seed oil. The RSOPE was added into water-ethylene glycol (W-EG) solution as lubricant additive. Dispersion stability and rheological properties were investigated. We used a four-ball tribotester to assess the lubrication performance of W-EG based fluid with the RSOPE additive. The stainless-steel surface was analyzed using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Good dispersion stability was observed in the RSOPE/W-EG solutions. Furthermore, nonNewtonian fluid behavior at low shear rates and Newtonian fluid behavior at high shear rates was More >

Kyung Sung Kim¹, Moo-Hyun Kim^2,*, Hakun Jang³, Hee Chen Cho⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.1, pp. 11-29, 2018, DOI:10.31614/cmes.2018.00199

Abstract A new MPS (Moving Particle Semi-implicit) method is developed to simulate the behaviors and interactions of multiple fine solid particles as a continuum. As fluid particles are affected by viscosity, so solid particles are affected by friction. The solid particle dynamics for landslides, dumping, and gravity sorting etc. which can be difficult to simulate using conventional MPS methods, are modeled in this paper using the developed multi-solid-particle MPS method that benefits from drawing comparisons with the corresponding fluid particle behaviors. The present MPS results for dumping solid particles are verified against the corresponding DEM (Discrete… More >

Xiaohua Zhu^1,*, Li Zeng¹, Bo Li¹

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.2, pp. 631-660, 2019, DOI:10.32604/cmes.2019.06755

Abstract The complicated geological conditions will bring great challenges to the drillstring of horizontal wells for the reason that the increase of the well depth in SichuanChongqing region. Since drillstring failure and friction during drilling are generally caused by drillstring vibration, great importance must be attached to computer simulation methods for the prediction of drillstring vibration. A finite element model considering axial, lateral and torsional vibration is established. In order to verify the established numerical model, an indoor experimental device based on the similarity principle was established. The vibration characteristics of three shale gas horizontal wells… More >

L. Fratini¹, S. Pasta²

Structural Durability & Health Monitoring, Vol.1, No.4, pp. 245-252, 2005, DOI:10.3970/sdhm.2005.001.245

Abstract In the last years friction stir welding (FSW) has reached a quite large diffusion in the welding of aluminium alloys, difficult to be welded with traditional technologies. The objective of this investigation was to investigate the influence of FSW process parameters on the fatigue strength of the developed joints. Moreover, in order to improvement the strength of joint, the effect of a post-welding treatment has been highlighted; what is more a surface finish treatment has been developed with the aim to eliminate the stress concentration caused by welding process on the surface of the joints. More >

R. Vignjevic¹, T. De Vuyst², J. C. Campbell¹

CMES-Computer Modeling in Engineering & Sciences, Vol.13, No.1, pp. 35-48, 2006, DOI:10.3970/cmes.2006.013.035

Abstract An approach to the treatment of contact problems involving frictionless sliding and separation under large deformations in meshless methods is proposed. The method is specially suited for non-structured spatial discretisation. The contact conditions are imposed using a contact potential for particles in contact. Inter-penetration is checked as a part of the neighbourhood search. In the case of conventional SPH contact conditions are enforced on the boundary layer 2h thick while in the case of the normalized SPH contact conditions are enforced for the particles lying on the contact surface. The implementation of the penalty based More >

Sanjay K. Sharma¹, V. R. Kalamkar^{1, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.3, pp. 295-319, 2018, DOI:10.3970/cmes.2018.114.295

Abstract The three-dimensional numerical investigation of an incompressible flow through rib roughened solar air heater is carried out. A combination of thin transverse and truncated ribs is attached on the absorber plate to study its effect on the heat transfer and friction factor. The parameters in the form of Reynolds number (Re) of 4000-16000, relative roughness pitch (P/e) of 8-18 and relative roughness height (e/Dh) of 0.0366-0.055 is considered for the analysis. The CFD code ANSYS FLUENT is used to solve the governing equations of turbulent flow. The RNG k–ε turbulence model is used to solve More >

Li Liping, Pan Yishan, Zhang Mengtao

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.4, pp. 103-104, 2011, DOI:10.3970/icces.2011.016.103

Abstract The block model of effect of anomalous low friction in rock mass was established based on plasticity kinetics and theoretical analysis. And the normal stress formulas of contact interface between rock stratum and roof on elastic stage and elastic-plasticity stage were presented. The theoretical analysis indicates that under dynamic loading, the normal stress of contact interface between rock stratum and roof on elastic stage and elastic-plasticity stage of simple beam both reduce, and the reduction amplitude are both great. The friction force of the contact interface reduces sharply, therefore the existence of effect of anomalous More >

Yu.A. Goritskiy¹, D.G. Tigetov¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.14, No.4, pp. 99-102, 2010, DOI:10.3970/icces.2010.014.099

Abstract It is well-known that process of friction depends immensely on the surface roughness. Also, surfaces change while in friction. Roughness change is influenced by many factors such as shape of asperities, physical characteristics of materials, load, sliding velocity, lubricant and others. It was shown experimentally that roughness reaches a steady form (known as ``equilibrium roughness'') while running-in process. It is ``equilibrium roughness'' that determines a stationary friction mode. More >

Chih-Wei Hsieh¹, Chien-Li Wu¹, Cheng-Kuo Sung^1,2

The International Conference on Computational & Experimental Engineering and Sciences, Vol.13, No.2, pp. 33-34, 2009, DOI:10.3970/icces.2009.013.033

Abstract Molecular dynamics (MD) simulation has been demonstrated as a promising method to analyze formation and friction mechanisms of the nanoimprint process. Especially, it provides a useful tool for investigating critical issues that are generally difficult to be examined by the experiment because of cross talks among influential factors or attainability of direct measurement. This study utilized the friction mechanism to explore the factors that would affect the quality of mold replication in the direct nanoimprint. Those factors included mechanical properties of thin films, interaction force between mold and thin-film materials, and surface roughness of the… More >