Search results for "Friction."
showing 10 items of 350 documents
A Comparative Study of Mechanical and Microstructural Behavior for Metal Active Gas and Friction Stir Welded Micro-Alloyed Structural Steel
2022
Manufacturing tiny components into gigantic structures seems unimaginable without welding connections, whether it is for materials, parts, structures, or equipment. In the recent competitive market scenario, manufacturing industries are desperately looking for a viable alternative to fusion-based conventional material joining technologies, to improve upon cost-effectiveness along with performance. The present investigation is to evaluate the performance of structural steel thick plate joints prepared by advanced solid-state friction stir welding (FSW) over conventional metal active gas welding (MAG). The FSW experiments were carried out with different tool designs and configurations. The ou…
Shape optimization in contact problems based on penalization of the state inequality
1986
The paper deals with the approximation of optimal shape of elastic bodies, unilaterally supported by a rigid, frictionless foundation. Original state inequality, describing the behaviour of such a body is replaced by a family of penalized state problems. The relation between optimal shapes for the original state inequality and those for penalized state equations is established. peerReviewed
Residual Stress Effects on Fatigue Crack Growth in Ti-6Al-4V Friction Stir Welds
2008
Recent studies have illustrated a predominant role of the residual stress on the fatigue crack growth in friction stir welded joints. In this study, the role of the residual stress on the propagation of fatigue cracks orthogonal to the weld direction in a friction stir welded Ti-6Al-4V joint was investigated. A numerical prediction of the fatigue crack growth rate in the presence of the residual stresses was carried out using AFGROW software; reasonable correspondence between the predictions and the experimental results were observed when the effects of residual stress were included in the simulation.
Comparison of frictional resistance between passive self-ligating brackets and slide-type low-friction ligature brackets during the alignment and lev…
2019
Background To compare the frictional resistance between passive self-ligating brackets and conventional brackets with low-friction ligature under bracket/archwire and root/bone interface during dental alignment and leveling. Material and methods A tridimensional model of the maxilla and teeth of a patient treated with conventional brackets, and slide ligatures was generated employing the SolidWorks modeling software. SmartClip self-ligating brackets and Logic Line conventional brackets were assembled with slide low-friction ligatures, utilizing archwires with different diameters and alloys used for the alignment and leveling stage. Friction caused during the bracket/archwire interface and s…
Oscillations of dynamical systems applied in drilling : analytical and numerical methods
2013
Height as a predictor of Parkinson's disease: a case-control study.
2005
Residual a posteriori error estimation for frictional contact with Nitsche method
2023
We consider frictional contact problems in small strain elasticity discretized with finite elements and Nitsche method. Both bilateral and unilateral contact problems are taken into account, as well as both Tresca and Coulomb models for the friction. We derive residual a posteriori error estimates for each friction model, following [Chouly et al, IMA J. Numer. Anal. (38) 2018, pp. 921-954]. For the incomplete variant of Nitsche, we prove an upper bound for the dual norm of the residual, for Tresca and Coulomb friction, without any extra regularity and without a saturation assumption. Numerical experiments allow to assess the accuracy of the estimates and their interest for adaptive meshing …
On the friction/tangential restitution problem: Independent friction-restitution modeling of sphere rebound with arbitrary spin
2023
Most descriptions of collision events introduce coefficients of friction and tangential restitution which vary significantly with the impact angle, in contrast with the independence of the normal coefficient of restitution with this parameter. A redefinition of the coefficients of friction and tangential restitution based on the idea that friction and restitution effects can be treated as being mutually independent, provides a satisfactory description of experimental data using a ‘constant’ restitution coefficient independent on the impact angle. This independent friction-restitution modeling is developed here for the rebound of a homogeneous sphere having an arbitrary spin on a rough massi…
Alteration-Induced Volcano Instability at La Soufrière de Guadeloupe (Eastern Caribbean)
2021
International audience; Volcanoes are unstable structures that deform laterally and frequently experience mass wasting events. Hydrothermal alteration is often invoked as a mechanism that contributes significantly to volcano instability. We present a study that combines laboratory experiments, geophysical data, and large-scale numerical modeling to better understand the influence of alteration on volcano stability, using La Soufrière de Guadeloupe (Eastern Caribbean) as a case study. Laboratory experiments on variably altered (advanced argillic alteration) blocks show that uniaxial compressive strength, Young's modulus, and cohesion decrease as a function of increasing alteration, but that …
Tribological and Mechanical Properties of the Nanostructured Superlattice Coatings with Respect to Surface Texture
2022
This research is funded by the Latvian Council of Science, project “Carbon-rich self-healing multifunctional nanostructured smart coatings (NSC) for high-tech applications using high-power confined plasma technology for their deposition”, project No. 2019/1-0385.