Yusuf Cunedioglu - Academia.edu (original) (raw)

Papers by Yusuf Cunedioglu

Composite Structures, Jul 1, 2009

In this paper, failure load and failure mode of woven glass epoxy composite plates with one and t... more In this paper, failure load and failure mode of woven glass epoxy composite plates with one and two serial pinned joints are analyzed experimentally and numerically. Two variables are investigated during analyses; the distance from the free edge of the plate to the diameter of the first-hole (E/D) ratio, and the width of the specimen to the diameter of the holes (W/D) ratios. Experiments are carried out according to the ASTM D 953 1. Numerical study is performed by means of ANSYS finite element analysis program. Yamada Sun failure criterion is used for failure analyses. Mechanical properties of the composite material are obtained from the ASTM standards. The results showed that maximum failure load is obtained at E/D=4 and W/D=4. A good agreement is found between experimental results and numerical predictions.

Niğde Ömer Halisdemir Üniversitesi mühendislik bilimleri dergisi, Jul 31, 2017

Bu calismada yuzeyi elyaf takviyeli kompozit malzemeyle kaplanmis aluminyum kirisin statik ve bur... more Bu calismada yuzeyi elyaf takviyeli kompozit malzemeyle kaplanmis aluminyum kirisin statik ve burkulma analizi incelenmistir. Calismada Euler-Bernoulli kiris teorisi kullanilarak problemin cozumu sonlu elemanlar metoduyla gerceklestirilmistir. Problemin analizi icin MATLAB’ta sonlu elemanlar kodu yazilarak deplasman ve burkulma yukleri hesaplanmistir. Calismada yuzey ve cekirdek tabaka kalinliginin, kompozit malzeme hacim oraninin, lif oryantasyon acisinin, farkli kiris konfigurasyonlarinin ve farkli boy kalinlik oranlarinin deplasman ve burkulma yukleri uzerindeki etkisi incelenmistir. Incelenen bu parametrelerin kirisin deplasman ve burkulma yuklerini onemli olcude etkiledigi gozlemlenmistir .

Advances in Structural Engineering, Jul 10, 2020

Free vibration analysis of a single edge cracked multi-layered symmetric sandwich stepped Timoshe... more Free vibration analysis of a single edge cracked multi-layered symmetric sandwich stepped Timoshenko beams, made of functionally graded materials, is studied using finite element method and linear elastic fracture mechanic theory. The cantilever functionally graded beam consists of 50 layers, assumed that the second stage of the beam (step part) is created by machining. Thus, providing the material continuity between the two beam stages. It is assumed that material properties vary continuously, along the thickness direction according to the exponential and power laws. A developed MATLAB code is used to find the natural frequencies of three types of the stepped beam, concluding a good agreement with the known data from the literature, supported also by ANSYS software in data verification. In the study, the effects of the crack location, crack depth, power law gradient index, different material distributions, different stepped length, different cross-sectional geometries on natural frequencies and mode shapes are analysed in detail.

Mechanics Based Design of Structures and Machines, Jan 31, 2011

In this study, a laminated cantilever composite beam is studied in frequency domain by using some... more In this study, a laminated cantilever composite beam is studied in frequency domain by using some popular model order reduction techniques. In the analyses, component mode synthesis (CMS) and quasi-static mode synthesis (QSM1, QSM2) methods are applied to semi-discrete finite element equations to obtain reduced order models for structural analyses. The performance of the model order reduction methods is compared.

Niğde Ömer Halisdemir Üniversitesi mühendislik bilimleri dergisi, Jul 5, 2022

Bu çalışmada bir ucu ankastre diğer ucu serbest olan kompozit sandviç kirişlerin serbest titreşim... more Bu çalışmada bir ucu ankastre diğer ucu serbest olan kompozit sandviç kirişlerin serbest titreşimi incelenmiştir. Çatlaklı ve çatlaksız halde sandviç kirişin doğal frekanslarının doğrulanması analitik ve ANSYS yazılım programı ile sağlandıktan sonra daha hızlı çözüm elde etmek adına analizler ANSYS programı ile gerçekleştirilmiştir. Çalışmada U ve V çatlak yapısının doğal frekans değerleri üzerindeki etkisi farklı çatlak konumlarında, farklı çatlak derinliklerinde ve farklı çatlak genişlikleri için incelenmiştir. Çalışmada 3 ve 5 tabakalı sandviç kirişler incelenmiştir. İncelenen bu parametrelerin kirişin doğal frekans değerlerini önemli ölçüde etkilediği gözlemlenmiştir. In this study, the free vibration of composite sandwich beams, one end of which is fixed and the other end is free, was investigated. The verification of the natural frequencies of the sandwich beam with and without cracks was provided with analytical and ANSYS software. The analyses were carried out with the ANSYS program in order to obtain a faster solution. In the study, the effect of U and V crack structures on natural frequency values was investigated for different crack locations, crack depths, and different crack widths. In the study, 3-layer and 5-layer sandwich beams were examined. It has been observed that these investigated parameters significantly affect the natural frequency values of the beam.

Materialwissenschaft Und Werkstofftechnik, 2021

In this paper modal analysis is performed on a symmetric aluminum beam which is coated with funct... more In this paper modal analysis is performed on a symmetric aluminum beam which is coated with functionally graded material containing porosities. A polynomial function is used to vary the density and elasticity through the thickness of the coating, while the effective elastic modulus and density are found with classical lamination theory. To achieve a truthful modeling the gradually changing mechanical properties of the coating are modeled as 25 layers of material, while each individual layer is isotropic and homogeneous. MATLAB is used to write a finite element code and Timoshenko beam elements are used to include shear deformation effects. To show the influences of crack location, crack depth, porosity and the polynomial function index on the natural beam frequencies a parametric study is conducted. Multiple boundary conditions were also considered and it was found that the natural frequency values were significantly affected by the studied parameters.

İTÜDERGİSİ/d, Apr 29, 2011

Model derecesi düşürme teknikleri büyük boyutlu dinamik simülasyonlarda işlem zamanını azaltmak v... more Model derecesi düşürme teknikleri büyük boyutlu dinamik simülasyonlarda işlem zamanını azaltmak ve süper eleman yaratmak amacıyla kullanılmaktadır. Bu çalışmada, Sonlu Elemanlar Metodu (SEM) kullanılarak popüler model derecesi düşürme tekniklerinden "Component Mode Synthesis (CMS)", "Quasi-Static Mode Synthesis (QSM)", Doğrusal olmayan en küçük kareler metodu(DOEK) ve Alt uzay temelli "Subspace-Based" tanımlama (AUT) metotları frekans ve zaman uzayında yapısal bir problem üzerinde incelendi. DOEK metodu ile AUT metotlarının, CMS ve QSM metotlarından daha iyi sonuçlar verdiği, fakat model derecesi arttıkça DOEK metodunun yakınsamadığı ve AUT metodunun yüksek dereceden modeller uydurduğu görülmüştür. Çalışmanın ikinci bölümünde ayrık eşdeğerlik prensibine göre geliştirilen "Impulse Response Invariant (IRI)", İleri Farklar ve Newmark zaman entegrasyon metotları model derecesi düşürme tekniği olarak kullanıldı.

Structural Engineering and Mechanics, Jul 10, 2015

Archive of Applied Mechanics, Jan 6, 2021

In this paper, the free vibration of an aluminum beam coated with imperfect and damaged functiona... more In this paper, the free vibration of an aluminum beam coated with imperfect and damaged functionally graded material is investigated. The imperfections consist of porosities, while 4 evenly distributed cracks represent the damage profile. A polynomial function is used to vary the density and elasticity through the thickness of the coating, while the effective elastic modulus and density are found with classical lamination theory. To achieve a truthful modeling, the gradually changing mechanical properties of the coating are modeled with 25 layers of material. The individual layers are isotropic and homogeneous. Numerical solutions are found with the finite element method using Timoshenko beam elements. MATLAB is used to write a finite element code, and the beam natural frequencies are found. To show the influences of porosity, crack depth, coating thickness and the polynomial function index ( n ) on the natural beam frequencies, a parametric study is conducted. It was found that the natural frequency values were significantly affected by the studied parameters.

Materials research express, 2020

This paper presents the free vibration analysis of an edge cracked non-uniform symmetric beam mad... more This paper presents the free vibration analysis of an edge cracked non-uniform symmetric beam made of functionally graded material. The Timoshenko beam theory is used for the finite element analysis of the multi-layered sandwich beam and the cantilever beam is modeled by 50 layers of material. The material properties vary continuously along the thickness direction according to the exponential and power laws. A MATLAB code is used to find the natural frequencies of two types of non-uniform beams, having a constant height but an exponential or linear width variation along the length of the beam. The natural frequencies of the beam are verified with ANSYS software as well as with available literature and good agreement is found. In the study, the effects of different parameters such as crack location, crack depth, power-law index, geometric index and taper ratio on natural frequencies are analyzed in detail.

AIAA Journal, Feb 1, 2020

This paper presents a theoretical investigation on the free vibration of a symmetric beam consist... more This paper presents a theoretical investigation on the free vibration of a symmetric beam consisting of an aluminum core coated with functionally graded material. The elastic modulus and density ar...

Composites Part B-engineering, Oct 1, 2011

In this study, a novel reinforcing method for glass-fiber reinforced composites, which consists o... more In this study, a novel reinforcing method for glass-fiber reinforced composites, which consists of inter-adherend glass fibers (IAF) that get through the composite adherend like a pin, was investigated experimentally and numerically. Two types of joints were investigated. One is ...

Finite Elements in Analysis and Design, Feb 1, 2006

In this study, some popular model order reduction and superelement techniques are studied in freq... more In this study, some popular model order reduction and superelement techniques are studied in frequency and time domains. Frequency domain identification (FDI) methods are also applied to semidiscrete finite element equations to obtain reduced order models for ...

Niğde Ömer Halisdemir Üniversitesi mühendislik bilimleri dergisi, Aug 7, 2020

Bu çalışmada çekirdek tabakası alüminyum ve yüzeyleri porosite ihtiva eden fonksiyonel derecelend... more Bu çalışmada çekirdek tabakası alüminyum ve yüzeyleri porosite ihtiva eden fonksiyonel derecelendirilmiş malzeme (FDM) ile kaplı simetrik yapıda ankastre sandviç bir kirişin serbest titreşim analizi incelenmiştir. Fonksiyonel derecelendirilmiş malzemenin elastisite modülü ve yoğunluğu kirişin tabaka kalınlığı boyunca bir polinom fonksiyonla değiştiği kabul edilmiştir. FDM'yi gerçeğe yakın bir şekilde temsil etmek için kaplama kalınlığının 25 tabakadan oluştuğu ve her bir tabaka kendi içinde homojen izotrop olarak modellenmiştir. Bu yapılara ait efektif yoğunluk ve elastisite modülü tabakalı kompozit kiriş teorisi kullanılarak belirlenmiştir. Çalışmada birinci mertebe kayma deformasyonu içeren Timoshenko kiriş teorisi kullanılarak problemin çözümü sonlu elemanlar metoduyla gerçekleştirilmiştir. Kirişin doğal frekanslarının hesaplanması için MATLAB'ta sonlu elemanlar kodu yazılmıştır. Çalışmada porosite hacim oranının (a), çekirdek tabaka kalınlığının FDM kalınlık oranına (h/H), kiriş açıklığının yüksekliğine oranının (L/H) ve FDM'nin mekanik özelliklerini belirleyen polinom parametresinin (n) doğal frekansların üzerindeki etkisi incelenmiştir. İncelenen parametrelerin kirişin doğal frekanslarını önemli ölçüde etkilediği gözlemlenmiştir.

Structural Engineering and Mechanics, Dec 25, 2015

In this study, free vibration analysis of an edge cracked multilayered symmetric sandwich beams m... more In this study, free vibration analysis of an edge cracked multilayered symmetric sandwich beams made of functionally graded materials are investigated. Modelling of the cracked structure is based on the linear elastic fracture mechanics theory. Material properties of the functionally graded beams change in the thickness direction according to the power and exponential laws. To represent functionally graded symmetric sandwich beams more realistic, fifty layered beam is considered. Composition of each layer is different although each layer is isotropic and homogeneous. The considered problem is carried out within the Timoshenko first order shear deformation beam theory by using finite element method. A MATLAB code developed to calculate natural frequencies for clamped and simply supported conditions. The obtained results are compared with published studies and excellent agreement is observed. In the study, the effects of crack location, depth of the crack, power law index and slenderness ratio on the natural frequencies are investigated.

Structural Engineering and Mechanics, Jul 10, 2014

The aim of this study is to investigate the effects of the beam aspect ratio(L/h), hole diameter,... more The aim of this study is to investigate the effects of the beam aspect ratio(L/h), hole diameter, hole location and stacking layer sequence ([0/45/-45/90] s , [45/0/-45/90] s and [90/45/-45/0] s) on natural frequencies of glass/epoxy perforated beams under room and high (40, 60, 80, and 100°C) temperatures for the common clamped-free boundary conditions (cantilever beam). The first three out of plane bending free vibration of symmetric laminated beams is studied by Timoshenko's first order shear deformation theory. For the numerical analyses, ANSYS 13.0 software package is utilized. The results show that the hole diameter, stacking layer sequence and hole location have important effect especially on the second and third mode natural frequency values for the short beams and the high temperatures affects the natural frequency values significantly. The results are presented in tabular and graphical form.

Archive of Applied Mechanics

Materialwissenschaft und Werkstofftechnik, 2021

Ömer Halisdemir Üniversitesi Mühendislik Bilimleri Dergisi, 2020

Ömer Halisdemir Üniversitesi Mühendislik Bilimleri Dergisi, 2017

Bu çalışmada, farklı sıcaklık parametrelerinde Winkler tipi elastik ortamla destekli ve elastik o... more Bu çalışmada, farklı sıcaklık parametrelerinde Winkler tipi elastik ortamla destekli ve elastik ortam desteksiz ankastre bir kompozit kirişin eksenel yük etkisindeki burkulma ve serbest titreşimi incelenmiştir. Kompozit kiriş tarafsız eksene göre simetrik tabakalı plakalardan oluşturulmuştur. Çalışmada Euler Bernoulli kiriş teorisi kullanılarak problemin çözümü sonlu elemanlar metoduyla gerçekleştirilmiştir. Problemin simülasyonu için MATLAB'ta sonlu elemanlar kodu yazılarak burkulma yükleri ve doğal frekanslar hesaplanmıştır. Çalışmada farklı açı dizilişlerine sahip tabakalı kompozit kirişlerin burkulma yükleri ve doğal frekans değerlerinin sıcaklıkla değişimleri incelenmiştir. Ayrıca eksenel kuvvetlerin ve Winkler parametresinin farklı kiriş tasımları için burkulma yüklerine ve doğal frekans değerlerine olan etkileri araştırılmıştır.