SIMULATING DRY SLIDING FRICTION WITH BLOCK-SPRING MODELS

Download
2023-1-12
AMIREGHBALI, AYDIN
Dry sliding friction occurs not only in engineering applications such as jet turbine disk-blade joints, dry friction dampers, and rocket engine gimbals but also along geological faults. In this thesis, dry sliding friction is studied using the Maxwell-slip model and the Burridge-Knopoff model, which consist of block-spring units pulled on a rigid flat by a driver. The initial spring extension, stiffness, and normal load values of the block-spring units are specified by different probabilistic methods. The objective is to investigate the effect of these parameters on the evolution of overall friction and interface slip. The Maxwell-slip model with a single randomized parameter, initial lateral spring extension, can produce a range of frictional behavior from stick-slip to steady-sliding. Two asperity-based approaches, one based on Nayak's probability density functions and the other based on the fractal geometry, are used to characterize the Maxwell-slip model units as well. Both approaches generate random asperity heights and tip curvatures. Stick-slip behavior was not observed using these approaches. Considering the inertial force in the Maxwell-slip model can make friction force oscillate even to negative values at high-enough sliding speeds. The Burridge-Knopoff model with an initial linear lateral force distribution can generate both stick-slip and steady-sliding regimes. The friction force drops are accompanied by pulse-like propagation of slip zones at the interface. The propagation speed of these slip zones can exceed the longitudinal wave speed under the Coulomb friction law.

Suggestions

EFFECT OF INTENTIONAL DRY FRICTION DAMPING ON THE PERFORMANCE OF AN ELASTOMERIC ENGINE MOUNT
Boral, Caner; Ciğeroğlu, Ender; Korkmaz, Ibrahim (2010-07-24)
Automotive engine mounts are used to protect engine from road irregularities and to isolate transmission of vibrations created by the engine which have a drastic effect on the noise generated inside the passenger cabin. Most common types of engine mounts are elastomeric and hydraulic mounts, the former having better vibration isolation characteristics whereas the latter displays better shock isolation. Elastomeric mounts are widely used for their low initial cost, while hydraulic mounts with inertia track a...
Effect of Oil Feed Groove on Compressor Piston Lubrication
Hacıoğlu, Bilgin; Dursunkaya, Zafer (2008-07-14)
Oil feed grooves are implemented in reciprocating compressor piston applications to assure a constant supply of lubricating oil on bearing surfaces and decrease friction loss. In a hermetically sealed compressor, due to small clearances encountered, oil supply becomes critical in order to prevent the boundary lubrication. Due to the small size of the piston and small piston–cylinder clearance, a partial lubrication regime is present. In the current study, a model that solves Reynolds’ equation for piston-cy...
AN ENERGY APPROACH TO SLIDING OF SINGLE-SPAN SIMPLY SUPPORTED SLAB-ON-GIRDER STEEL HIGHWAY BRIDGES WITH DAMAGED BEARINGS
Dicleli, Murat (Wiley, 1995-03-01)
This paper investigates the non-linear inelastic seismic response of existing single-span simply supported bridges having bearings which can remain stable and slide after their anchor bolts are ruptured. A simplified equivalent model is developed for the inelastic analysis of these single-span simply supported bridges. Non-linear inelastic time-history analyses are conducted for various acceleration inputs. It is found that narrower bridges with longer spans may have considerable sliding displacements and f...
Effect of ground on aerodynamics and longitudinal static stability of a non-slender delta wing
Koçak, Göktuğ; Yavuz, Mehmet Metin (2022-11-01)
© 2022 Elsevier Masson SASIn this paper, the effect of ground on aerodynamics and longitudinal static stability of a non-slender delta wing with sweep angle of 45 degree and thickness-to-chord ratio (t/c) of 5.9% was characterized at Reynolds number of 9×104 in a low-speed wind tunnel using force and pressure measurements. The measurements were conducted for angles of attack varying between 0≤α≤30 degrees and non-dimensional heights between 3%≤h/c≤107% and height stability of the wing based on aerodynamic c...
An accelerated aerodynamic optimization approach for a small turbojet engine centrifugal compressor
Ceylanoğlu, Arda; Ulaş, Abdullah; Department of Mechanical Engineering (2009)
Centrifugal compressors are widely used in propulsion technology. As an important part of turbo-engines, centrifugal compressors increase the pressure of the air and let the pressurized air flow into the combustion chamber. The developed pressure and the flow characteristics mainly affect the thrust generated by the engine. The design of centrifugal compressors is a challenging and time consuming process including several tests, computational fluid dynamics (CFD) analyses and optimization studies. In this s...
Citation Formats
A. AMIREGHBALI, “SIMULATING DRY SLIDING FRICTION WITH BLOCK-SPRING MODELS,” Ph.D. - Doctoral Program, Middle East Technical University, 2023.