Volume 17, Issue 1, 2008

LETTER: STACKING SEQUENCE EFFECTS ON NATURAL FREQUENCY OF LAMINATED COMPOSITE BEAMS

Muzaffer Topcu, Gökmen Atlihan*, Hasan Çallioglu and E. Sahin Çonkur

Department of Mechanical Engineering, Pamukkale University, 20070, Kinikli, Denizli, Turkey

* Author to whom correspondence should be addressed, e-mail: gatlihan@pau.edu.tr

ABSTRACT
In this study, the natural frequencies of composite laminated beams are considered using experimental and theoretical approaches while the effects of stacking sequences of composite laminated beams on natural frequencies are investigated using theoretical approaches. A theoretical model of the laminated composite beam has been developed. Numeric calculations are carried out by means of a computer package program, ANSYS 7.0 that implements the finite element method (FEM). It has been concluded that in all of the modes considered, natural frequencies in the beam of angle (0°)₁₂ are maximum values, natural frequencies in the beam composed of [(±52°)3]s are the lowest values ac-cording to the other stacking sequence and while natural frequencies in the beam of higher angles from [(±52°)3]s are getting higher, they at angle (90°)₁₂ take more higher values. Furthermore, some of the results obtained from these theoretical analyses are compared with the experimental results using the composite laminated beam at [(0°/90°)3]s produced in Izoreel Composite Isolated Materials Company, Izmir, Turkey. Its natural frequencies are calculated both analytically and numerically. It has been concluded that experimental, theoretical and numerical results are very close to each other.

Keywords: Natural frequency, vibration, analytical method, FEM