Flexural behaviour of square UHPC-filled hollow steel section beams

Guler, Soner,Copur, Alperen,Aydogan, Metin Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.43 No.2

This paper presents an experimental investigation of the flexural behavior of square hollow steel section (HSS) beams subjected to pure bending. Totally six unfilled and nine ultra high performance concrete (UHPC)-filled HSS beams were tested under four-point bending until failure. The effects of the steel tube thickness, the yield strength of the steel tube and the strength of concrete on moment capacity, curvature, and ductility of UHPC-filled HSS beams were examined. The performance indices named relative ductility index (RDI) and strength increasing factor (SIF) were investigated with regard to different height-to-thickness ratio of the specimens. The flexural strengths obtained from the tests were compared with the values predicted by Eurocode 4, AISC-LRFD and CIDECT design codes. The results showed that the increase in the moment capacity and the corresponding curvature is much greater for thinner HSS beams than thicker ones. Eurocode 4 and AISC-LRFD predict the ultimate moment capacity of the all UHPC-filled HSS beams conservatively.

Spatial Analysis of Two-Wheeled Vehicles Traffic Crashes: Osmaniye in Turkey

Guler Yalcin,H.Sebnem Duzgun 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.7

To achieve a sustainable traffic management and sustainable transportation planning in urban areas one of the tools that can be used effectively is Geographic Information Systems. In Turkey Transportation Department under Civil Engineering deals with roads and railways which are open to public such as inner city and outer city traffic arrangements with General Directorate of Security. This paper aims to analyze road traffic accident distribution according to the vehicle types involved in the accidents for urban areas in sample of Osmaniye, Turkey. While chi-square test is used for non-spatial analysis kernel density, nearest neighbor distances and Kfunction analysis are applied to determine the existence of clustering and hotspots. The network statistics are executed through SANET (Spatial Analysis on a NETwork) V4.1 that runs on ArcMap 10 and for better visualization and understanding the analysis 3D analysis are generated in ArcScene 10. It is realized that the accidents involving two-wheeled vehicles have a high percentage in all accidents. Also the possible reasons to use two-wheeled vehicles at a high rate in the city center are searched by Location Quotient Technique. The importance of this study is to use GIS as a management system for accident analysis with statistical analysis methods.

Axial behavior of FRP-wrapped circular ultra-high performance concrete specimens

Guler, Soner Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.50 No.6

Ultra-High Performance Concrete (UHPC) is an innovative new material that, in comparison to conventional concretes, has high compressive strength and excellent ductility properties achieved through the addition of randomly dispersed short fibers to the concrete mix. This study presents the results of an experimental investigation on the behavior of axially loaded UHPC short circular columns wrapped with Carbon-FRP (CFRP), Glass-FRP (GFRP), and Aramid-FRP (AFRP) sheets. Six plain and 36 different types of FRP-wrapped UHPC columns with a diameter of 100 mm and a length of 200 mm were tested under monotonic axial compression. To predict the ultimate strength of the FRP-wrapped UHPC columns, a simple confinement model is presented and compared with four selected confinement models from the literature that have been developed for low and normal strength concrete columns. The results show that the FRP sheets can significantly enhance the ultimate strength and strain capacity of the UHPC columns. The average greatest increase in the ultimate strength and strain for the CFRP- and GFRP-wrapped UHPC columns was 48% and 128%, respectively, compared to that of their unconfined counterparts. All the selected confinement models overestimated the ultimate strength of the FRP-wrapped UHPC columns.

The Effect of Dietary Black Cumin Seeds (Nigella Sativa L.) on the Performance of Broilers

Guler, Talat,Dalkilic, B.,Ertas, O.N.,Ciftci, M. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.3

Three hundred and sixty sexed 3-day-old broiler chicks were divided randomly into six treatment groups (control, antibiotic and black cumin at four levels) of 60 birds each. Black cumin seeds at 0.5%, 1%, 2% or 3% and avilamycin at 10 mg/kgt were added to the basal diet and their effects determined on feed intake, daily live weight gain, feed conversion ratio and carcass characteristics. There were no significant differences in daily feed intake at 21 and 42 days (p>0.05). Average daily gain was significantly different between the treatments. The birds fed the diet containing 1% black cumin seeds and antibiotic were the highest average daily gain, followed by those the other treatment diets and negative control (p<0.05). From 1 to 42 days of age, feed conversion ratios were improved significantly by supplementation with 1% black cumin seeds and with antibiotic (p<0.05) by approximately 5% compared to the control group. Similarly, the highest cold carcass, thigh, breast, wing, neck and liver weights were observed in the 1% black cumin and antibiotic groups (p<0.05). Accordingly, 1% supplementation of black cumin seeds to diets could be considered as an alternative natural growth promoter for poultry instead of antibiotics.

Response of a rectangular plate-column system on a tensionless Winkler foundation subjected to static and dynamic loads

Guler, K.,Celep, Z. Techno-Press 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.21 No.6

The response of a plate-column system having five-degree-of-freedom supported by an elastic foundation and subjected to static lateral load, harmonic ground motion and earthquake motion is studied. Two Winkler foundation models are assumed: a conventional model which supports compression and tension and a tensionless model which supports compression only. The governing equations of the problem are obtained, solved numerically and the results are presented in figures to demonstrate the behavior of the system for various values of the system parameters comparatively for the conventional and the tensionless Winkler foundation models.

Flexural behaviour of square UHPC-filled hollow steel section beams

Soner Guler,Alperen Çopur,Metin Aydogan 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.43 No.2

This paper presents an experimental investigation of the flexural behavior of square hollow steel section (HSS) beams subjected to pure bending. Totally six unfilled and nine ultra high performance concrete (UHPC)-filled HSS beams were tested under four-point bending until failure. The effects of the steel tube thickness, the yield strength of the steel tube and the strength of concrete on moment capacity, curvature, and ductility of UHPC-filled HSS beams were examined. The performance indices named relative ductility index (RDI) and strength increasing factor (SIF) were investigated with regard to different height-to-thickness ratio of the specimens. The flexural strengths obtained from the tests were compared with the values predicted by Eurocode 4, AISC-LRFD and CIDECT design codes. The results showed that the increase in the moment capacity and the corresponding curvature is much greater for thinner HSS beams than thicker ones. Eurocode 4 and AISC-LRFD predict the ultimate moment capacity of the all UHPC-filled HSS beams conservatively.

Axial behavior of FRP-wrapped circular ultra-high performance concrete specimens

Soner Guler 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.50 No.6

Ultra-High Performance Concrete (UHPC) is an innovative new material that, in comparison to conventional concretes, has high compressive strength and excellent ductility properties achieved through the addition of randomly dispersed short fibers to the concrete mix. This study presents the results of an experimental investigation on the behavior of axially loaded UHPC short circular columns wrapped with Carbon-FRP (CFRP), Glass-FRP (GFRP), and Aramid-FRP (AFRP) sheets. Six plain and 36 different types of FRP-wrapped UHPC columns with a diameter of 100 mm and a length of 200 mm were tested under monotonic axial compression. To predict the ultimate strength of the FRP-wrapped UHPC columns, a simple confinement model is presented and compared with four selected confinement models from the literature that have been developed for low and normal strength concrete columns. The results show that the FRP sheets can significantly enhance the ultimate strength and strain capacity of the UHPC columns. The average greatest increase in the ultimate strength and strain for the CFRP- and GFRP-wrapped UHPC columns was 48% and 128%, respectively, compared to that of their unconfined counterparts. All the selected confinement models overestimated the ultimate strength of the FRP-wrapped UHPC columns.

Euler Equation Approach for Emerging-market Macro Models

Bulent Guler,윤택 한국국제경제학회 2013 International Economic Journal Vol.27 No.2

This paper focuses on how to obtain numerical solutions to emerging-market DSGE models with occasionally binding constraints by using the Euler equation, rather than using value functions of households. The main point is that the Euler-equation approach works in a fast and simple way for a variety of recent emerging-market macro models. An important reason behind this point is that it is relatively easy to pin down the functional form of aggregate equilibrium conditions in these models. The time-iteration method is applied to Euler equations of a small open-economy with overborrowings. It is discussed how to use the Euler equation approach to recent models of sovereign debt and to show that the presence of the Laffer-curve of debt-revenues leads us to use the piecewise parameterized-expectations approach.

BI-ROTATIONAL HYPERSURFACE SATISFYING ∆IIIx =AxIN 4-SPAC

Erhan Guler,Yusuf Yaylı,,Hasan Hilmi Hacısalihoglu 호남수학회 2022 호남수학학술지 Vol.44 No.2

We examine the bi-rotational hypersurface x = x(u, v, w) with the third Laplace-Beltrami operator in the four dimensional Euclidean space E 4. Giving the i-th curvatures of the hypersurface x, we obtain the third Laplace-Beltrami operator of the bi-rotational hypersurface satisfying ∆IIIx =Ax for some 4 × 4 matrix A.

Rotational hypersurfaces constructed by double rotation in five dimensional Euclidean space E^5

Erhan Guler 호남수학회 2023 호남수학학술지 Vol.45 No.4

We introduce the rotational hypersurface x = x(u, v, s, t) constructed by double rotation in five dimensional Euclidean space E^5. We reveal the first and the second fundamental form matrices, Gauss map, shape operator matrix of x. Additionally, defining the i-th curvatures of any hypersurface via Cayley-Hamilton theorem, we compute the curvatures of the rotational hypersurface x. We give some relations of the mean and Gauss-Kronecker curvatures of x. In addition, we reveal ∆x =Ax, where A is the 5 × 5 matrix in E^5.