THE ANALYSIS OF CIRCULAR PLATES VIA NEURO-FUZZY TECHNIQUE

Mühendislik sistemlerinin analizi genelde sayısal tekniklere dayanmaktadır. Yüzeysel taşıyıcı sistemler günümüze kadar çeşitli sayısal metotlar ile çalışılmıştır. Bu çalışmada dairesel plakların analizi, farklı bir hesaplama tekniği olarak son yıllarda kullanılmaya başlanan mantıksal programlama tekniği ile verilmiş ve geliştirilen program yardımıyla çeşitli örnekler çözülmüştür. Yapay sinir ağını eğitmek için çok farklı eğitim seti kullanılmış ve yeterli hassasiyet sağlanmıştır. Ağın eğitimi sırasında bağlantı ağırlıklarının ve kullanılan temel değişkenlerin belirlenmesinde fuzzy küme teorisinden faydalanılmıştır. Elde edilen sonuçlar, sayısal teknikler ile elde edilen sonuçlar ile karşılaştırılmış ve mantıksal programlama tekniğinin yapı mühendisliğinde kullanılabilecek alternatif bir metot olduğu vurgulanmıştır. The analysis of engineering systems are generally based on numerical technique. Surfaces portal systems had been studied with different numerical methods until now. In this study, the analysis of circular plates is given with logical programming technique which has been used in the recent years as a different programming technique and various examples are solved by means of developed program. Various training sets are used to train the artificial neural network and sufficient sensibility is maintained. Fuzzy set theory is used during the training of the network, evaluation of the connections weights and determination of the basic variables used in training of network. The obtained results are compared with the results of the numerical techniques and it has been emphasized that logical programming technique is an alternate method which can be used in structural engineering

ON THE NUMERICAL SOLUTION OF SOME BOUNDARY VALUE PROBLEMS VIA GENERALIZED DIFFERENTIAL QUADRATURE METHOD

Gerek mühendislik sistemlerinin analizinde ve gerekse uygulamalı disiplinlerde diferansiyel denklemlerin çözümü büyük bir öneme sahiptir. Çoğunlukla bir sınır değer ve/veya başlangıç değer formunda olan bu denklemlerin analitik çözümü çoğu durumda mümkün değildir. Bu amaçla yeter yaklaşıklıkta çözümler elde etmek için günümüze kadar pek çok sayısal analiz yöntemi geliştirilmiştir. Bu yöntemlerin her birinin; gerektirdikleri bilgisayar kapasiteleri, zaman ve hassasiyet açısından biri birine göre avantajları ve dezavantajları mevcuttur. Çalışmada genelleştirilmiş diferansiyel quadrature metodu kısaca tanıtılmış, mühendislikte ve temel bilimlerde sıkça karşılaşılan bazı tür sınır değer probleminin sayısal çözümü sunulmuştur. Genelleştirilmiş diferansiyel quadrature yönteminin bilinen bazı tip diferansiyel denklemlerin çözümünde kullanılacak alternatif bir metot olduğu vurgulanmıştır. The solution of differential equations has a great importance in the analysis of engineering systems and applied disciplines. It is not always possible to obtain the analytical solutions of these equations, which has a boundary value and/or initial value form as usual. For this purpose, it has been improved many numerical analysis method to obtain the adequate solutions up to now. All of these methods have a relative advantage and disadvantage with respect to each other because of the time aspect and the sensitivity. In this study, Generalized Differential Quadrature (GDQ) method was briefly introduced and presented the numerical solutions of some type boundary value problems that have been confronted in engineering and basic sciences often. It has been emphasized that generalized Differential Quadrature method is an alternate method for the solution of known type differential equations

THE ANALYSIS OF TIME DEPENDENT DEFORMATION IN R. C. MEMBERS BY ARTIFICIAL NEURAL NETWORK

In the past ten years, Artificial neural networks have emerged as analysis and solving technique with capabilities suited to many structural analysis problems. Diverse problems in engineering may be solved accurately with computers. In structural engineering many solution techniques exist. Artificial neural networks have evolved as a new computing paradigm, and many engineering applications have been studied. In this paper the time dependent deformation such as; creep, shrinkage, in R. C. members have been calculated by means of Artificial Neural Network (ANN) and the results have been compared with the experimental study given by other authors

Free Vibration Analysis of Elastic Beams Using Harmonic Differential Quadraure (HDQ)

Harmonic differential quadrature method is developed for the free vibration analysis of linear elastic beams. In the method of differential quadrature, partial space derivatives of a function appearing in a differential equation are approximated by means of a polynomial expressed as the weighted linear sum of the function values at a preselected grid of discrete points. The weighting coefficients are treated as the unknowns. Applying this concept to the governing differential equation of beam gives a set of linear simultaneous equations, which are solved for the unknown weighting coefftcients by accounting for the boundary conditions. Beams of different support combinations such as clamped, simply supported, guided, and free are selected to demonstrate the accuracy of the method. Flexural vibration case is taken into consideration. First two frequencies are obtained in the applications. Numerical results are presented to illustrate the method and demonstrate its efficiency

Frequency, bending and buckling loads of nanobeams with different cross sections

The bending, stability (buckling) and vibration response of nano sized beams is presented in this study based on the Eringen's nonlocal elasticity theory in conjunction with the Euler-Bemoulli beam theory. For this purpose, the bending, buckling and vibration problem of Euler-Bernoulli nanobeams are developed and solved on the basis of nonlocal elasticity theory. The effects of various parameters such as nonlocal parameter eoa, length of beam L, mode number n, distributed load q and cross-section on the bending, buckling and vibration behaviors of carbon nanotubes idealized as Euler-Bernoulli nanobeam is investigated. The transverse deflections, maximum transverse deflections, vibrational frequency and buckling load values of carbon nanotubes are given in tables and graphs

Free vibration analysis silicon nanowires surrounded by elastic matrix by nonlocal finite element method

Higher-order theories are very important to investigate the mechanical properties and behaviors of nanoscale structures. In this study, a free vibration behavior of SiNW resting on elastic foundation is investigated via Eringen's nonlocal elasticity theory. Silicon Nanowire (SiNW) is modeled as simply supported both ends and clamped-free Euler-Bernoulli beam. Pasternak two-parameter elastic foundation model is used as foundation. Finite element formulation is obtained nonlocal Euler-Bernoulli beam theory. First, shape function of the Euler-Bernoulli beam is gained and then Galerkin weighted residual method is applied to the governing equations to obtain the stiffness and mass matrices including the foundation parameters and small scale parameter. Frequency values of SiNW is examined according to foundation and small scale parameters and the results are given by tables and graphs. The effects of small scale parameter, boundary conditions, foundation parameters on frequencies are investigated