Akademik Veri Yönetim Sistemi
Tezin Türü: Doktora
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Havacılık Ve Uzay Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2023
Tezin Dili: İngilizce
Öğrenci: AYDIN AMIREGHBALI
Danışman: Demirkan Çöker
Özet:
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.