Structural coupling of two nonlinear structures

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Tezin Türü: Yüksek Lisans

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

Tezin Onay Tarihi: 2018

Öğrenci: ÇAĞRI TEPE

Danışman: ENDER CİĞEROĞLU

Özet:

In mechanical design, modelling and analysis of a complex structure can be simplified with dividing the structure into substructures; therefore, any change in the structure can be addressed easily which is referred as “structural coupling”. Utilization of proper coupling techniques, it is possible to understand the behavior of the whole structure by considering the behavior of its substructures. For linear structures, coupling is a common technique; however, in most of the engineering structures, nonlinearities are also encountered; therefore, it is required to extend linear coupling methods to nonlinear systems. Although, studies on nonlinear coupling are available in literature, existing methods are limited to coupling of structures where one substructure is linear and the other is nonlinear or two linear substructures coupled with a nonlinear element. In this thesis, a structural coupling method is proposed to couple two-nonlinear substructures. Similar to linear coupling methods, the proposed method considers the compatibility of internal forces at the connection degrees of freedom in addition to displacements. The proposed method is simulated with two different conditions which are coupling of identified substructures and coupling of identified substructure with neural network trained substructure. Since, the substructures are nonlinear, the resulting system of nonlinear differential equations are converted into a set of nonlinear algebraic equations by using Describing Function Method, which are solved by using Newton’s method with arclength continuation.