Fibonacci Differential Equation and Associated Spiral Curves

The Fibonacci differential equation is defined with analogy from the Fibonacci difference equation. The linear second order differential equation is solved for suitable initial conditions. The solutions constitute spirals in the polar coordinates. The properties of the spirals with respect to the Fibonacci numbers and the differences between the new spirals and classical spirals are discussed

Elastik Yatak Üzerine Yerleştirilmiş Eğri Mikro Kirişin 2:1 İç Rezonansları

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2013Bu çalışmada, ideal olmayan sınır şartlarına sahip hafif eğrilikli rezonans mikro kirişin dinamik davranışı araştırılmıştır. Eğri mikro kirişin uçları basit basit mesnetlenmiştir ve kiriş nonlineer elastik yatak üzerine yerleştirilmiştir. Küçük AC yükünden dolayı eğri mikro kirişin zorlamalı titreşim tepkisi çok ölçekli metodun (perturbasyon metodu) direk uygulanması ile analitik olarak elde edilmiştir. Titreşimin iki modu arasında 2:1 iç rezonansları çalışılmıştır. Genlik ve faz denklemleri elde edilmiştir. Düzgün rejim çözümleri ve çözümlerin kararlılığı tartışılmış ve genlik-faz modülasyon denklemlerinin bifürkasyon analizi sunulmuştur. İdeal olmayan sınır şartlarının sistemin titreşimine etkileri araştırılmıştır.In this study, the dynamic behaviour of a slightly curved resonant microbeam having non-ideal boundary conditions is investigated. The ends of the curved microbeam are on immovable simple supports and the microbeam is resting on a non-linear elastic foundation. The forced vibration response of curved microbeam due to the small AC load is obtained analytically by means of direct application of the method of multiple scales (a perturbation method). Two-to-one internal resonances between any two modes of vibration are studied. Amplitude and phase modulation equations are obtained. Steady state solutions and stability are discussed, and a bifurcation analysis of the amplitude and phase modulation equations are presented. The effects of the non ideal boundary conditions on the vibrations of the microbeam are examined

Cooling Intensification of a Continuously Moving Stretching Surface Using Different Types of Nanofluids

The effect of different types of nanoparticles on the heat transfer from a continuously moving stretching surface in a concurrent, parallel free stream has been studied. The stretching surface is assumed to have power-law velocity and temperature. The governing equations are converted into a dimensionless system of equations using nonsimilarity variables. Resulting equations are solved numerically for various values of flow parameters. The effect of physical quantities on the temperature profiles is discussed in detail

Perturbation Analysis of Spindle Speed Variation in Machine Tool Chatter

Spindle speed variation has been shown to be an effective method for chatter control. In this paper, a single-degree-of-freedom regenerative type chatter equation is treated using perturbation methods. Rather than using the time coordinate, the angle of revolution is taken as the independent coordinate for maintaining a constant delay in the equations. The spindle speed is taken to be harmonically varying about a constant mean speed. Approximate analytical solutions are sought using the method of strained parameters, a perturbation technique. The amplitude of speed fluctuations (ε) is assumed to be small, and solutions are constructed using this parameter as the perturbation parameter. The stability lobes for constant spindle speeds are calculated exactly. By using the approximate perturbation analysis, the gain in stability is calculated for variable spindle speeds. The analysis is valid for (ε) values up to 0.02 (i.e., 2% of the constant mean speed). Solutions are verified using numerical simulations of the original equation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68588/2/10.1177_107754639700300302.pd

Exact Solutions of a Remarkable Fin Equation

A model "remarkable" fin equation is singled out from a class of nonlinear (1+1)-dimensional fin equations. For this equation a number of exact solutions are constructed by means of using both classical Lie algorithm and different modern techniques (functional separation of variables, generalized conditional symmetries, hidden symmetries etc).Comment: 6 page

Kuvvetli Nonlineer Sistemler İçin Çok Ölçekli Lindstedt Poincare Tekniği

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2013Çok ölçekli metot ve Lindstedt-Poincare tekniğinin birleştirilmesi esasına dayanan yeni bir perturbasyon metodu ortaya atılmıştır. Yeni metot lineer sönümlü osilatör, Duffing denklemi, sönümlü kübik nonlineer denklem, kuadratik ve kübik nonlineer denklem ve zorlamalı Duffing denklemine uygulanmıştır. Klasik çok ölçekli metot ve yeni metodu kullanarak yaklaşık analitik çözümler elde edilmiştir. Bu çözümler ana denklemin sayısal çözümü ile karşılaştırılmıştır. Yeni metot kuvvetli nonlineer sistemler için çok iyi sonuçlar vermiştir.A new perturbation method combining the Method of Multiple Scales and Lindstedt Poincare techniques is proposed. The new method is applied to Linear damped oscillator, Duffing equation, damped cubic nonlinear equation, an equation with quadratic and cubic nonlinearities and forced Duffing equation. Approximate analytical solutions are obtained using the classical Multiple scales method and the new method. Both solutions are contrasted with the direct numerical solutions of the original equation. The new method produces much better results for strong nonlinearities

İLKÖĞRETİM DİN KÜLTÜRÜ VE AHLÂK BİLGİSİ DERSLERİNDE HİKÂYE KULLANIMI

Bu arastırmada, ilkögretim DKAB derslerinde hikaye kullanımının dersin hangi asamalarında ne sekilde olması gerektigi örneklerle açıklanmıs ve bu kullanımının amaca ulasmasını saglamaya yönelik olarak dersin tüm asamalarında dikkat edilmesi gereken hususlar tespit edilmeye çalısılmıstır. Bununla birlikte DKAB ders programı dogrultusunda hikaye kullanımına dayalı ders isleme örnekleri sunulmustur

The effects of kinematic condensation on internally resonant forced vibrations of shallow horizontal cables

This study aims at comparing non-linear modal interactions in shallow horizontal cables with kinematically non-condensed vs. condensed modeling, under simultaneous primary external and internal resonances. Planar 1:1 or 2:1 internal resonance is considered. The governing partial-differential equations of motion of non-condensed model account for spatio-temporal modification of dynamic tension, and explicitly capture non-linear coupling of longitudinal/ vertical displacements. On the contrary, in the condensed model, a single integro-differential equation is obtained by eliminating the longitudinal inertia according to a quasi-static cable stretching assumption, which entails spatially uniform dynamic tension. This model is largely considered in the literature. Based on a multi-modal discretization and a second-order multiple scales solution accounting for higher-order quadratic effects of a infinite number of modes, coupled/uncoupled dynamic responses and the associated stability are evaluated by means of frequency- and force-response diagrams. Direct numerical integrations confirm the occurrence of amplitude-steady or -modulated responses. Non-linear dynamic configurations and tensions are also examined. Depending on internal resonance condition, system elasto-geometric and control parameters, the condensed model may lead to significant quantitative and/or qualitative discrepancies, against the non-condensed model, in the evaluation of resonant dynamic responses, bifurcations and maximal/minimal stresses. Results of even shallow cables reveal meaningful drawbacks of the kinematic condensation and allow us to detect cases where the more accurate non-condensed model has to be used