Optimum buckling design of axially layered graded uniform columns

Veysel Alkan

doi:10.3139/120.110734

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Optimum buckling design of axially layered graded uniform columns

Veysel Alkan

Published/Copyright: April 21, 2015

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From the journal Materials Testing Volume 57 Issue 5

Abstract

This study presents optimum buckling design of axially layered graded uniform columns. Firstly, characteristic equations for determining critical buckling loads for all end conditions are obtained using the transfer matrix method and for each case, square of this equation is selected as a fitness function. Due to the explicitly unavailable objective function for the critical buckling loads as a function of volume fraction and length of the column, initially, prescribed value is assumed for it and then the design variables satisfying constraints are determined. Different boundary conditions are considered. Among them, maximum increment up to 19 % of the critical buckling load is attained for the simply supported case. Finally, the strongest column configurations are determined.

Kurzfassung

In diesem Beitrag wird das optimierte Knicklast-Design für axial geschichtete und einheitlich gradierte Stützen vorgestellt. Zunächst wurden die charakteristischen Gleichungen zur Bestimmung der kritischen Knickbeanspruchungen für alle Endbedingungen ermittelt, wobei das Verfahren mittels Übertragungsmatrix für jeden der Fälle angewandt wurde und das Quadrat dieser Gleichung als Fitnessfunktion gewählt wurde. Auf Grund der nicht eindeutig verfügbaren objektiven Funktion für die kritischen Knickbeanspruchungen als Funktion des Volumenanteils und der Länge der Stütze, wurde in erster Näherung ein vorgeschriebener Wert angenommen und dann nach den erfüllenden Bedingungen der Designvariablen gesucht. Hierbei wurden verschiedene Randbedingungen berücksichtigt. Darunter wurde ein maximales Inkrement von 19 % der kritischen Knickbeanspruchung für den einfach unterstützten Fall erreicht. Schließlich wurden auch die stärksten Stützkonfigurationen bestimmt.

§Correspondence Address, Assistant Prof. Dr. Veysel Alkan, Department of Mechanical Engineering, Pamukkale University, Kinikli, 20070 Denizli, Turkey, E-mail: valkan@pau.edu.tr

Assist. Prof. Veysel Alkan, born in 1973, is currently working in the Department of Mechanical Engineering of Pamukkale University in Denizli, Turkey as a teaching and research member (Assistant Professor). His main research interests are vibration, structural dynamics and mechanics of composite materials, and applications of numerical methods (finite element methods) in engineering areas.

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Published Online: 2015-04-21

Published in Print: 2015-04-30

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https://doi.org/10.3139/120.110734