Akademik Veri Yönetim Sistemi
Tez Türü: Doktora
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği Bölümü, Türkiye
Tez Danışmanı: Serkan Dağ
Tezin Onay Tarihi: 2024
Tezin Dili: İngilizce
Desteklendiği Program: Diğer
Özet:
In the present work, a solution
method for the elastodynamic contact problems of rigid punches is developed for
several smart systems in two dimensional medium. The considered composite
structures always comprise a homogeneneous elastic substrate covered by a
coating involving single layer or many sub-layers. The wear resistant coatings
encountered in the industry possess heterogeneous structure and their
properties are defined by gradation functions. Analytical contact solutions of
such coatings generally focus on a single layer coating with exponential
gradation through the depth of the coating as it is easier to work with the
exponential function in the solution of differential equations. Yet, this
assumption lacks in reality due to its limitations since the gradation function
can be any function. The mathematical challenges of the random gradation
functions are overcome by the discretization of the coating with homogeneous
multi-layer modelling (HMLM) method. After homogenization of the structure, the
formulation is based on the wave equations of plane elastodynamics and
Maxwell’s equations depending on the coating type. By examining each layer with
its own boundary conditions and applying Galilean and Fourier Transform
techniques, the singular integral equation of the contact problem is derived
for four different punches. In the next step, this equation is numerically
solved by Jacobi expansion-collocation method to obtain the outputs. The main
emphasize is the investigation of the influences of the coating type, the speed
of the punch, the coating thickness-to-contact length ratio and the coefficient
of dynamic friction on contact stresses, electric displacement and magnetic
induction.