An analytical study on minimum confinement in spiral columns

Download

index.pdf

Date

2005

Author

Özkaya, Cenan

Metadata

Show full item record

Item Usage Stats

239
views

102
downloads

The minimum spiral ratio equation given in the codes is derived by equating the strength at the second peak to the strength at the first peak for spiral columns tested under uniaxial load. In this study, specimen behavior under combined bending and axial load was taken as basis while deriving proposed equations. Analyses were carried out by using a Moment-Curvature program. For normal strength concrete, one regression and one simplified equation giving minimum spiral ratio are proposed. Difference between two equations arises from the number in front of (Ac/Ack). In regression equation, this number is calculated by means of a function. In simplified equation, this number is a constant. For high strength concrete, a different regression equation is proposed which is valid for concrete strengths up to 95 MPa. Simplified equation proposed for normal strength concrete is also proposed for high strength concrete up to concrete strengths of 120 MPa. It was found that; (i) Simplified equation proposed for normal and high strength concrete yielded consistent results in the range of variables studied; (ii) Except some points, regression equations yielded consistent results; (iii) It is recommended to use simplified equation instead of regression and code equations since it yields more consistent results than code and regression equations. Keywords: Confined Concrete, Ductility, Moment-Curvature, Minimum Spiral Volumetric Ratio

Subject Keywords

Architectural Engineering.

URI

http://etd.lib.metu.edu.tr/upload/12606353/index.pdf
https://hdl.handle.net/11511/15198

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

A Mathematical Model for Simulation of Flow Rate and Chamber Pressures in Spool Valves Afatsun, Ahmet C.; Balkan, Raif Tuna (ASME International, 2019-02-01) In this paper, a mathematical model to simulate the pressure and flow rate characteristics of a spool valve is derived. To improve the simulation accuracy, the discharge coefficient through the spool valve ports is assumed to be a function of both the Reynolds number and the orifice geometry rather than treating it as a constant. Parameters of the model are determined using the data obtained by computational fluid dynamics (CFD) analyses conducted on two-dimensional axisymmetric domains using ANSYS FLUENT 1...
An experimental study of residual fiber strains in Ti-15-3 continuous fiber composites Pickard, S.M.; Miracle, D.B.; Majumdar, B.S.; Kendig, K.L.; Rothenflue, L.; Çöker, Demirkan (Elsevier BV, 1995-01-01) A simplified experimental technique to determine the axial fiber residual strain in continuously-reinforced metal matrix composites is described. The residual fiber strains in two Ti-15V-3Cr-3Al-3Sn/SiC metal matrix composites have been measured with this technique. Residual fiber strains on the order of 0.2% are measured in the as-processed condition, and the residual stresses approach zero after testing the composite in tension to failure at room temperature. A conceptual description of the effect of tens...
A computational procedure for estimating residual stresses and secondary plastic flow limits in nonlinearly strain hardening rotating shafts Eraslan, Ahmet Nedim (Springer Science and Business Media LLC, 2005-03-01) A computational procedure to estimate the residual stress distributions and the limit angular speeds for avoiding secondary plastic deformation in nonlinearly strain hardening rotating elastic-plastic shafts is given. The model is based on von Mises yield condition, J(2) deformation theory and a Swift-type hardening law. The boundary value problem for the governing nonlinear differential equation is solved by a shooting method using Newton iterations with numerically approximated tangent. Solid as well as h...
Comparison of design codes for seismically isolated structures Acar, Emre; Akyüz, Uğurhan; Department of Civil Engineering (2005) This study presents information on the design procedure of seismic base isolation systems. Analysis of the seismic responses of isolated structures, which is oriented to give a clear understanding of the effect of base isolation on the nature of the structure; and discussion of various isolator types are involved in this work. Seismic isolation consists essentially of the installation of mechanisms, which decouple the structure, and its contents, from potentially damaging earthquake induced ground motions. ...
A Mechanistic Model for Predicting Frictional Pressure Losses for Newtonian Fluids in Concentric Annulus SORGUN, MEHMET; Ozbayoglu, M. E. (Informa UK Limited, 2010-01-01) A mathematical model is introduced estimating the frictional pressure losses of Newtonian fluids flowing through a concentric annulus. A computer code is developed for the proposed model. Also, extensive experiments with water have been conducted at Middle East Technical University, Petroleum and Natural Gas Engineering Department Flow Loop and recorded pressure drop within the test section for various flow rates. The performance of the proposed model is compared with computational fluid dynamics (CFD) soft...

Citation Formats

C. Özkaya, “An analytical study on minimum confinement in spiral columns,” M.S. - Master of Science, Middle East Technical University, 2005.