Two-dimensional transient dynamic response of orthotropic layered media

Abu Alshaikh, Ibrahim
Turhan, Dogan
Mengi, Yalcin
In this study, two-dimensional transient dynamic response of orthotropic plane layered media is investigated. The plane multilayered media consist of N different generally orthotropic, homogeneous and linearly elastic layers with different ply angles. In the generally orthotropic layer, representing a ply reinforced by unidirectional fibers with an arbitrary orientation angle, the principal material directions do not coincide with body coordinate axes. The solution is obtained by employing a numerical technique which combines the use of Fourier transform with the method of characteristics. The numerical results are displayed in curves denoting the variations of stress and displacement components with time at different locations. These curves clearly reveal, in wave profiles, the scattering effects caused by the reflections and refractions of waves at the boundaries and at the interfaces of the layers, and also the effects of anisotropy caused by fiber orientation angle. The curves properly predict the sharp variations in the response at the neighborhood of the wave fronts, which shows the power of the numerical technique employed in the study. By suitably adjusting the elastic constants, the results for multilayered media with transversely isotropic layers, or layers with cubic symmetry, or isotropic layers can easily be obtained from the general formulation. Furthermore, solutions for some special cases, including Lamb's problem for an elastic half-space, are obtained and compared with the available solutions in the literature and very good agreement is found.


Two-dimensional transient wave propagation in viscoelastic layered media
Abu Alshaikh, I; Turhan, D; Mengi, Y (Elsevier BV, 2001-07-26)
Propagation of two-dimensional transient waves in multilayered viscoelastic media is investigated. The multilayered medium consists of N different isotropic, homogeneous and linearly viscoelastic layers with more than one discrete relaxation time. The top surface of the layered medium is subjected to dynamic in-plane surface tractions; whereas, the lower surface is free or fixed. A numerical technique which combines the Fourier transform with the method of characteristics is employed to obtain the solutions...
Some peculiarities of nematic-isotropic liquid phase transitions in monomorphic and polymorphic mesogens
Nesrullajev, Arif; Yurtseven, Hasan Hamit; Saliholu, Selami; Kazanc, Nadide (Elsevier BV, 2002-10-03)
In this study, the dynamics of the changes of the morphological properties in the nematic mesophase and in the heterophase regions of the phase transitions between the nematic mesophase and the isotropic liquid for the thermotropic mesogens have been investigated. Experimentally, we have obtained the thermal hysteresis for the investigated phase transitions. For the analysis of the phase transition temperatures and the peculiarities of the heterophase regions, the mean field theory has been used.
Monitoring the Microstructural Evolution in Spheroidized Steels by Magnetic Barkhausen Noise Measurements
DAVUT, Kemal; Gür, Cemil Hakan (Springer Science and Business Media LLC, 2010-12-01)
The aim of this study is to monitor nondestructively the degree of spheroidization in steels by Magnetic Barkhausen Noise (MBN) method. Various series of specimens consisting of either lamellar pearlite or partially/completely spheroidized carbides were produced from AISI 1060 steel by appropriate heat treatments. All specimens were characterized by metallographic examinations, hardness and MBN measurements. The results show that MBN signals are very sensitive to the variations in the microstructure caused ...
Single- and double-helix vortex breakdown as two dominant global modes in turbulent swirling jet flow
Vanierschot, Maarten; Mueller, Jens S.; Sieber, Moritz; Perçin, Mustafa; van Oudheusden, Bas W.; Oberleithner, Kilian (Cambridge University Press (CUP), 2020-01-25)
In this paper, we study the shape and dynamics of helical coherent structures found in the flow field of an annular swirling jet undergoing vortex breakdown. The flow field is studied by means of time-resolved tomographic particle image velocimetry measurements. The obtained flow fields are analysed using both classic and spectral proper orthogonal decomposition. Despite the simple geometrical set-up of the annular jet, the flow field is very complex. Two distinct large-scale helical flow structures are ide...
A parallel gas-kinetic Bhatnagar-Gross-Krook method for the solution of viscous flows on two-dimensional hybrid grids
Ilgaz, M.; Tuncer, İsmail Hakkı (Informa UK Limited, 2009-01-01)
In this study, a parallel implementation of gas-kinetic Bhatnagar-Gross-Krook method on two-dimensional hybrid grids is presented. Boundary layer regions in wall bounded viscous flows are discretised with quadrilateral grid cells stretched in the direction normal to the solid surface while the rest of the flow domain is discretised by triangular cells. The parallel solution algorithm on hybrid grids is based on the domain decomposition using METIS, a graph partitioning software. The flow solutions obtained ...
Citation Formats
I. Abu Alshaikh, D. Turhan, and Y. Mengi, “Two-dimensional transient dynamic response of orthotropic layered media,” 2006, vol. 41, p. 639, Accessed: 00, 2020. [Online]. Available: