Results 31 to 40 of about 19,670 (249)

Vibration and Control Characteristics of Downhole Drill String System

open access: yesShiyou jixie, 2022
Stick slip vibration seriously affects the life of drill string system,prolongs the drilling cycle,and endangers the safety of staff.In order to solve the problem of stick slip vibration caused by linear torque load and friction load in drilling ...
Ma Sunan   +6 more
doaj  

On the formation of limit cycle of the friction-induced stick-slip vibration in oilwell drillstring

open access: yesPetroleum, 2015
In this paper, the stick-slip vibration in oilwell drillstring is studied. The drilling system is modelled as a lumped-parameter torsional pendulum and the interaction between the drill bit and the rock is treated as Coulomb friction.
Xiaohua Zhu, Liping Tang
doaj   +1 more source

Induced and endogenous acoustic oscillations in granular faults

open access: yes, 2019
The frictional properties of disordered systems are affected by external perturbations. These perturbations usually weaken the system by reducing the macroscopic friction coefficient.
Ciamarra, M. Pica   +3 more
core   +1 more source

Sliding susceptibility of a rough cylinder on a rough inclined perturbed surface

open access: yes, 2004
A susceptibility function ${\chi}(L)$ is introduced to quantify some aspects of the intermittent stick-slip dynamics of a rough metallic cylinder of length $L$ on a rough metallic incline submitted to small controlled perturbations and maintained below ...
Bouchaud   +23 more
core   +1 more source

On the influence of external stochastic excitation on linear oscillators with subcritical self-excitation applied to brake squeal [PDF]

open access: yes, 2019
A characteristic of linear systems with self-excitation is the occurrence of non-normal modes. Because of this non-normality, there may be a significant growth in the vibration amplitude at the beginning of the transient process even in the case of ...
Gräbner, Nils   +3 more
core   +1 more source

Study on the Influence Factors Upon the Propensity to Stick-Slip Phenomenon During Vehicle Start-Up Process

open access: yesIEEE Access, 2020
The vibration caused by the friction characteristic of the clutch during the vehicle start-up process has an impact on driveline torsional oscillation.
Dongyang Wang   +4 more
doaj   +1 more source

Direct Metal Deposition of Graphene–Ti28Nb35.4Zr Matrix Composites With Enhanced Mechanical, Corrosion, and Biocompatibility Properties for Bone Implants

open access: yesAdvanced Engineering Materials, EarlyView.
Graphene nanoplatelet (0.1 wt.%) reinforcement significantly enhances the performance of β Ti‐28Nb‐35.4Zr alloy. Grain refinement, reduced water contact angle, and improved surface characteristics promote osteoblast adhesion and complete surface coverage after 7 days.
Khurram Munir   +5 more
wiley   +1 more source

From Wafers to Electrodes: Transferring Automatic Optical Inspection (AOI) for Multiscale Characterization of Smart Battery Manufacturing

open access: yesAdvanced Functional Materials, EarlyView.
Automat optical inspection (AOI) techniques in semiconductor fabrication can be leveraged in battery manufacturing, enabling scalable detection and analysis of electrode‐ and cell‐level imperfections through AI‐driven analytics and a digital‐twin framework.
Jianyu Li, Ertao Hu, Wei Wei, Feifei Shi
wiley   +1 more source

Relaxation Tribometry: A Generic Method to Identify the Nature of Contact Forces [PDF]

open access: yes, 2019
Recent years have witnessed the development of so-called relaxation tribometers, the free oscillation of which is altered by the presence of frictional stresses within the contact. So far, analysis of such oscillations has been restricted to the shape of
Bot, Alain Le   +3 more
core   +4 more sources

Polymer Infiltration Into SURMOF Channels Enables Hydrophobic and Solid‐Like Slippery Functional Thin Films

open access: yesAdvanced Functional Materials, EarlyView.
We report a polymer‐chain insertion strategy to fabricate pore‐threaded MOF thin films with precisely tuned surface chemistry and wettability. Grafting n‐alkane chains into the pillared layer Cu2(bdc)2(dabco) MOF thin film's vertical nanochannels enhances water stability, and induces hydrophobicity and lubricant‐free, solid‐like slippery behavior ...
Angana Borbora   +4 more
wiley   +1 more source

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