Oblique Surface Cracking and Crack Closure in an Orthotropic Medium under Contact Loading

Tez Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği Bölümü, Türkiye

Tez Danışmanı: Prof.Dr.Serkan Dağ

Tezin Onay Tarihi: 2018

Tezin Dili: İngilizce

Özet:

In this study, inclined surface cracks in an elastic orthotropic half-plane exposed

to contact loading at the material surface are examined for both open and closed

crack assumptions. At first, mixed mode stress intensity factors are computed for

fully open crack assumption depending on the solution of singular integral

equations, obtained by Full Fourier Transform techniques. Unless fully open

crack assumption is valid, the suitable crack closure mode is determined. Both

crack tip and full length closure modes are examined. Singular integral equations

are solved with a suitable expansion-collocation technique depending on the

closure mode. Finally, the closed portions of the cracks, contact pressure

distributions between crack faces and modified mode II stress intensity factors

are computed considering sliding crack face conditions. The main result of the

analyses is the influence of the material parameters, the crack orientation angle

and applied load on mixed mode stress intensity factors, closed portions of the

cracks and the contact pressure distributions in the closed parts.