Zafer KAZANCI - Academia.edu (original) (raw)
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Papers by Zafer KAZANCI
International Journal of Mechanical Sciences, 2023
Auxetic cellular structures have the potential to revolutionise sandwich panel cores due to their... more Auxetic cellular structures have the potential to revolutionise sandwich panel cores due to their potential superior energy absorption capability. Because of their negative Poisson's ratio, auxetics behave counterintuitively and contract orthogonally under an applied compressive force, resulting in a densification of material in the vicinity of the applied load. This study investigates three cellular structures and compares their compressive energy absorbing characteristics under in-plane and axial loading conditions. Three unit cell topologies are considered; a conventional hexagonal, re-entrant and double arrowhead auxetic structures. The samples were additively manufactured using two different materials, a conventional Nylon and a carbon fibre reinforced composite alternative (Onyx). Finite element simulations are experimentally validated under out of and in-plane loading conditions and the double arrowhead (auxetic) structure is shown to exhibit comparatively superior energy absorption. For the carbon fibre reinforced material, Onyx, the specific energy absorbed by the double arrowhead geometry was 125% and 244% greater than the hexagonal (non-auxetic) and re-entrant (auxetic) structures respectively.
Smart Materials and Structures, Oct 11, 2019
This paper includes in-plane stiffness and inertia effects on the motion of a laminated composite... more This paper includes in-plane stiffness and inertia effects on the motion of a laminated composite plate subjected to explosive pressure pulses. The geometric nonlinearity effects are taken into account with the von Karman large deflection theory of thin plates. Transverse shear stresses are ignored. The in-plane stiffness is taken into account as a difference of the analysis made before. All
Journal of Sound and Vibration, Nov 1, 2008
Thin-walled Structures, Mar 1, 2020
Proceedings of the Twelfth International Conference on Civil, Structural and Environmental Engineering Computing, Aug 14, 2009
The dynamic behaviors of laminated flat and tapered composite plates subjected to blast loads are... more The dynamic behaviors of laminated flat and tapered composite plates subjected to blast loads are investigated. Numerical solution techniques and their computational applications which are proposed before in the literature are summarized to show the accuracy and prediction of the response of blast loaded laminated composite plates with and without damping effects. It was shown the effect of damping is not significantly effective for the first peak response. However, it is considerable with the second peak and it becomes greater as time increases. The effect of chosen displacement functions for the approximate-numerical methods is indicated. Deflection and strain–time histories of plates obtained from experiment, finite element, and approximate-numerical methods are compared and found a good agreement.
Acta Mechanica Solida Sinica, Dec 1, 2012
ABSTRACT Nonlinear dynamic responses of a laminated hybrid composite plate subjected to time-depe... more ABSTRACT Nonlinear dynamic responses of a laminated hybrid composite plate subjected to time-dependent pulses are investigated. Dynamic equations of the plate are derived by the use of the virtual work principle. The geometric nonlinearity effects are taken into account with the von Kármán large deflection theory of thin plates. Approximate solutions for a clamped plate are assumed for the space domain. The single term approximation functions are selected by considering the nonlinear static deformation of plate obtained using the finite element method. The Galerkin Method is used to obtain the nonlinear differential equations in the time domain and a MATLAB software code is written to solve nonlinear coupled equations by using the Newmark Method. The results of approximate-numerical analysis are obtained and compared with the finite element results. Transient loading conditions considered include blast, sine, rectangular, and triangular pulses. A parametric study is conducted considering the effects of peak pressure, aspect ratio, fiber orientation and thicknesses.
International Journal of Non-linear Mechanics, Jun 1, 2011
International Journal of Impact Engineering, Apr 1, 2012
International Journal of Mechanical Sciences, 2023
Auxetic cellular structures have the potential to revolutionise sandwich panel cores due to their... more Auxetic cellular structures have the potential to revolutionise sandwich panel cores due to their potential superior energy absorption capability. Because of their negative Poisson's ratio, auxetics behave counterintuitively and contract orthogonally under an applied compressive force, resulting in a densification of material in the vicinity of the applied load. This study investigates three cellular structures and compares their compressive energy absorbing characteristics under in-plane and axial loading conditions. Three unit cell topologies are considered; a conventional hexagonal, re-entrant and double arrowhead auxetic structures. The samples were additively manufactured using two different materials, a conventional Nylon and a carbon fibre reinforced composite alternative (Onyx). Finite element simulations are experimentally validated under out of and in-plane loading conditions and the double arrowhead (auxetic) structure is shown to exhibit comparatively superior energy absorption. For the carbon fibre reinforced material, Onyx, the specific energy absorbed by the double arrowhead geometry was 125% and 244% greater than the hexagonal (non-auxetic) and re-entrant (auxetic) structures respectively.
Smart Materials and Structures, Oct 11, 2019
This paper includes in-plane stiffness and inertia effects on the motion of a laminated composite... more This paper includes in-plane stiffness and inertia effects on the motion of a laminated composite plate subjected to explosive pressure pulses. The geometric nonlinearity effects are taken into account with the von Karman large deflection theory of thin plates. Transverse shear stresses are ignored. The in-plane stiffness is taken into account as a difference of the analysis made before. All
Journal of Sound and Vibration, Nov 1, 2008
Thin-walled Structures, Mar 1, 2020
Proceedings of the Twelfth International Conference on Civil, Structural and Environmental Engineering Computing, Aug 14, 2009
The dynamic behaviors of laminated flat and tapered composite plates subjected to blast loads are... more The dynamic behaviors of laminated flat and tapered composite plates subjected to blast loads are investigated. Numerical solution techniques and their computational applications which are proposed before in the literature are summarized to show the accuracy and prediction of the response of blast loaded laminated composite plates with and without damping effects. It was shown the effect of damping is not significantly effective for the first peak response. However, it is considerable with the second peak and it becomes greater as time increases. The effect of chosen displacement functions for the approximate-numerical methods is indicated. Deflection and strain–time histories of plates obtained from experiment, finite element, and approximate-numerical methods are compared and found a good agreement.
Acta Mechanica Solida Sinica, Dec 1, 2012
ABSTRACT Nonlinear dynamic responses of a laminated hybrid composite plate subjected to time-depe... more ABSTRACT Nonlinear dynamic responses of a laminated hybrid composite plate subjected to time-dependent pulses are investigated. Dynamic equations of the plate are derived by the use of the virtual work principle. The geometric nonlinearity effects are taken into account with the von Kármán large deflection theory of thin plates. Approximate solutions for a clamped plate are assumed for the space domain. The single term approximation functions are selected by considering the nonlinear static deformation of plate obtained using the finite element method. The Galerkin Method is used to obtain the nonlinear differential equations in the time domain and a MATLAB software code is written to solve nonlinear coupled equations by using the Newmark Method. The results of approximate-numerical analysis are obtained and compared with the finite element results. Transient loading conditions considered include blast, sine, rectangular, and triangular pulses. A parametric study is conducted considering the effects of peak pressure, aspect ratio, fiber orientation and thicknesses.
International Journal of Non-linear Mechanics, Jun 1, 2011
International Journal of Impact Engineering, Apr 1, 2012