K. Hashiguchi¹, S. Ozaki²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.2, pp. 125-132, 2008, DOI:10.3970/icces.2008.006.125

Abstract The subloading-friction model with a smooth elastic-plastic sliding transition is extended so as to describe the reduction from the static to kinetic friction and the recovery of static friction. The reduction is formulated as the plastic softening due to the separations of the adhesions of surface asperities induced by the sliding and the recovery is formulated as the creep hardening due to the reconstructions of the adhesions of surface asperities during the elapse of time under a quite high actual contact pressure between edges of asperities. More >

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

The International Conference on Computational & Experimental Engineering and Sciences, Vol.3, No.2, pp. 107-112, 2007, DOI:10.3970/icces.2007.003.107

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 >

L. Rodríguez-Tembleque¹, J.A. González¹, R. Abascal¹, K.C. Park², C.A. Felippa²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.2, No.1, pp. 21-28, 2007, DOI:10.3970/icces.2007.002.021

Abstract This work presents an interface treatment method based on localized Lagrange Multipliers (LLM) to solve frictional contact problems between two 3D elastic bodies. The connection between the solids is done using a displacement frame intercalated between the interfaces meshes, and the LLM are collocated at the interface nodes. The Boundary Elements Method (BEM) is used to compute the influence coefficients of the surface points involved, and contact conditions are imposed using projection functions. The LLM provides a partitioned formulation which preserves software modularity, facilitates non-matching meshes treatment and passes the contact patch test [4]. More >

A.N. Guz¹, V.V. Zozulya²

CMES-Computer Modeling in Engineering & Sciences, Vol.22, No.2, pp. 119-128, 2007, DOI:10.3970/cmes.2007.022.119

Abstract The frictional contact interaction of the edges of a finite plane crack is studied for the case of normal incidence of a harmonic SH-shear wave which produces antiplane deformation. The forces of contact interaction and displacement discontinuity are analyzed. Influence of the wave frequency on the stress intensity factor for different coefficients of friction is studied here. More >

S. Ozaki¹, K. Hashiguchi², T. Okayasu², D.H. Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.18, No.2, pp. 101-120, 2007, DOI:10.3970/cmes.2007.018.101

Abstract In order to analyze precisely not only the elastoplastic deformation phenomenon of saturated particle assembly such as soils, grains, powdered and tablet medicines or three dimensional cellular materials, but also the frictional sliding phenomenon between saturated particle assembly and other bodies, a particle assembly-water coupled finite element program, that incorporates both the subloading surface and the subloading-friction models, is developed. Subsequently, simulations of the compaction behavior of saturated particle assembly under strain rate control are performed. It is revealed by the numerical experiment adopting the finite element program that the frictional sliding behavior of the contact boundary 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 >

J. Ma², H. Lu², B. Wang², R. Hornung³, A. Wissink³, R. Komanduri^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.14, No.2, pp. 101-118, 2006, DOI:10.3970/cmes.2006.014.101

Abstract A new method for multiscale simulation bridging two scales, namely, the continuum scale using the generalized interpolation material point (GIMP) method and the atomistic scale using the molecular dynamics (MD), is presented and verified in 2D. The atomistic strain from the molecular dynamics simulation is determined through interpolation of the displacement field into an Eulerian background grid using the same generalized interpolation functions as that in the GIMP method. The atomistic strain is consistent with that determined from the virial theorem for interior points but provides more accurate values at the boundary of the MD… 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 >

Wanlin Guo^1,2, Huajian Gao²

CMES-Computer Modeling in Engineering & Sciences, Vol.7, No.1, pp. 19-34, 2005, DOI:10.3970/cmes.2005.007.019

Abstract A systematic investigation is performed on energy dissipation related interaction force associated with interlayer motion of sliding, rotation and telescoping between any two possible neighboring carbon nanotubes. In particular, we analyze the interlayer corrugation energy and sliding, rotation and telescoping resistance force associated with the Lennard-Jones potential as well as a registry-dependent graphitic potential. It is found that the interlayer resistance associated with both of these potentials can vary with the morphology, length and diameter of the two tubes. Energy dissipation related fluctuation of the resistant force can be as low as 10^-18N/atom between the most More >

Yaxin Song¹, D. Michael McFarland¹, Lawrence A. Bergman¹, Alexander F. Vakakis²

CMES-Computer Modeling in Engineering & Sciences, Vol.10, No.2, pp. 153-170, 2005, DOI:10.3970/cmes.2005.010.153

Abstract A general interface element is developed for dynamic response analysis of structures with jointed interfaces, which can account for damping due to both impact and friction. Contact effects are included through a segment-to-segment contact model which considers the stick-slip-slap behavior at every point along the joint interface. A nonlinear friction law is adopted at the interface to describe microscopic relative motion due to the deformation of the asperities on the interface. Numerical examples demonstrate that the general joint interface element is capable of accounting for both friction and impact damping in jointed interfaces, as well More >