Results 41 to 50 of about 14,428 (257)

Experiment and Simulation of Self-excited Torkbuster

Shiyou jixie, 2017
The stick-slip vibration is a technical bottleneck restricting for PDC bit in efficient drilling deep hard formation. To reduce the stick-slip vibration of drill bit during drilling deep hard formations, a torkbuster has been introduced.
Ma Hongyan, Wang Hongbo, Wang Daning, Zhang Jingsong, Zhang Yanrui, Quan Hulin   +5 more
doaj  

Transient torsional vibration analysis of marine diesel engine under short-circuit impact

Zhongguo Jianchuan Yanjiu
ObjectivesIn order to formulate an optimization scheme for the torsional vibration parameters of a marine diesel generator shaft system, it is necessary to analyze the transient torsional vibration characteristics of the diesel generator under short ...
Congcong XU, Gang LIANG, Jie TAO, Yafei JIAO, Jinyuan CHEN, Pengcheng WANG, Mengcan DENG   +6 more
doaj   +1 more source

Drilling Technology of Torsional Impact Rotary Reaming in Underground Coal Mine

Meikuang Anquan, 2020
According to the reaming requirement for large diameter directional drilling in hard rock of coal mine roof, the drilling technology of torsional impact rotary reaming is put forward. Based on the simulation results of FLUENT finite element software, the
ZHAO Jianguo
doaj   +1 more source

Affecting the Properties of Copper–Graphene Electroconductive Composite by Severe Plastic Deformation

Advanced Engineering Materials, EarlyView.
Copper‐based composites enhanced with carbon feature convenient mechanical properties and favorable electric conductivity. Processing via deformation and thermomechanical treatments can introduce advantageous microstructures further enhancing their performance. Herein, copper–graphene powder‐based composites are directly consolidated via rotary swaging
Radim Kocich, Lenka Kunčická, Pavel Czernek, Zifan Wang   +3 more
wiley   +1 more source

Chromatin fibers stabilize nucleosomes under torsional stress

Nature Communications, 2020
Torsional stress is generated during DNA replication and transcription, however, the propagation of twist in condensed chromatin is poorly understood.
Artur Kaczmarczyk, He Meng, Orkide Ordu, John van Noort, Nynke H. Dekker   +4 more
doaj   +1 more source

The impact of tibial torsion measurements on gait analysis kinematics

Acta Ortopédica Brasileira, 2014
To measure and compare tibial torsion values as assessed by goniometry and three-dimensional kinematics. In addition, the impact of each one of these measurements on kinematic and kinetic results for normal gait was determined.Twenty-three healthy and fully ambulatory patients were assessed, 11 women and 12 men, from 20 to 40 years old.
Lucareli, Paulo Roberto Garcia, Santos, Nadia Maria, Godoy, Wagner De, Bernal, Milena Moreira Barreto, Paes, Ângela Tavares, Ramalho Junior, Amancio   +5 more
openaire   +6 more sources

Molecular Dynamics Studies of Shape Memory Polymers: From Bead–Spring Models to Atomistic Simulations

Advanced Engineering Materials, EarlyView.
Coarse‐grained (left) and atomistic (right) models of the shape memory polymer ESTANE ETE 75DT3 are shown schematically. The two representations bridge molecular detail and mesoscopic description. Both models capture shape memory behavior, linking segmental mobility and conformational relaxation of anisotropic chains to macroscopic recovery, and ...
Fathollah Varnik
wiley   +1 more source

The Stress Singularity in a Stepped Bar Under Impact Torsion

JSME international journal. Ser. 1, Solid mechanics, strength of materials, 1989
An impact torsion problem for a steppedbar composed of two semi-infinite bars bonded completely at each end is investigated. A stress singularity occurs at the corner of the bars. Therefore the stress analysis proceeds considering this stress singularity by making use of the series expansion technique, and the problems are reduced to an infinite set of
TSUJI, Tomoaki, NODA, Naotake, SHIBUYA, Toshikazu, KOIZUMI, Takashi   +3 more
openaire   +3 more sources

Experimental Characterization and Constitutive Modeling of the Effect of Prior Inelastic Strain on the Viscoplastic Behavior of AD730 at 700 °C

Advanced Engineering Materials, EarlyView.
This study shows that superalloys used in aircraft engine disks become much more prone to deformation at high temperatures if they have been strained during manufacturing. This effect increases with the level of prior strain but eventually reaches a limit.
Fabio Machado Alves da Fonseca, Patrick Villechaise, Malik Durand, Arnaud Longuet, Florent Coudon, Loïc Signor, Julien De Jaeger, Dominique Eyidi, Nathalie Bozzolo, Jonathan Cormier   +9 more
wiley   +1 more source

Investigation of Axial–Torsional Vibration Characteristics and Vibration Mitigation Mechanism in Compound Percussive Drilling

Applied Sciences
Severe drill string vibrations, particularly stick–slip, significantly compromise drilling efficiency and tool longevity in deep hard formations. Compound percussive drilling (CPD) has emerged as a promising technique to mitigate these vibrations and ...
Wei Wang, Boyu Guo, Gonghui Liu, Chunqing Zha, Tian Chen, Jun Li   +5 more
doaj   +1 more source