Showing papers by "Subhendu K. Datta published in 1994"
TL;DR: In this paper, a wave function expansion is used to evaluate the complex amplitudes and the energy flux associated with the reflected waves in a variational method and a propagator matrix approach for laminated isotropic cylinders.
Abstract: A wave function expansion is used. Wave function are obtained using a propagator matrix approach for laminated isotropic cylinders and by a Rayleigh Ritz type approximation for laminate composite cylinders. The least square technique as well as the variational method are employed to evaluate the complex amplitudes and the energy flux associated with the reflected waves
26 citations
TL;DR: In this paper, a model study of the interaction of the A0 and S0 guided wave modes with the joint material is presented, and it is shown that as the frequency increases the coefficient of reflection shows resonant peaks at the cutoff frequencies of higher guided modes.
Abstract: Reflection of guided waves by a thin region of bonding material at the interface between two composite plates has been investigated in this paper. The study is motivated by the need to develop a quantitative ultrasonic technique to characterize properties of joints between two plates, which may be laminated and anisotropic. Although there have been some recent studies that have examined the reflection and transmission of surface waves at the interface between two plates, they consider the two plates to be semi‐infinite in thickness. Thus the mode conversion of waves into higher guided modes of the plates are not taken into account. In this paper, a model study of the interaction of the A0 and S0 guided wave modes with the joint material is presented. It is shown that as the frequency increases the coefficient of reflection shows resonant peaks at the cutoff frequencies of higher guided modes. These peaks become increasingly pronounced as the thickness of the joint increases. Another interesting feature is...
9 citations
01 Jan 1994
TL;DR: In this paper, the dispersion of guided waves in laminated plates has been studied over the past thirty years, and the results of these works can be found in the review article by Chimenti and Nayfeh [1] and in the symposium proceedings edited by Mal and Ting [2].
Abstract: Dispersion of guided waves in laminated plates has been studied over the past thirty years. Recent work has included anisotropic layering and the subtle effects of fluid loading. References to these works can be found both in the review article by Chimenti and Nayfeh [1] and in the symposium proceedings edited by Mal and Ting [2]. More recently Braga and Herrmann detailed the features of the dispersion spectrum for anisotropic periodic media using the sextic formalism developed by Stroh [3, 4], implying coupling of inplane and out-of-plane particle motion. A similar discussion of the analysis of the acoustical or mechanical filtering predicted for such periodic media is presented by Rousseau [5]. However, guided waves in a laminated plate where the laminae have very different anisotropic (isotropic) properties from one another have not received adequate attention. This problem, which is the subject of this paper, has relevance in ultrasonic characterization of layered bonded plates when the interface (interphase) bond properties can be quite different than those of the adjacent laminae and can change during service life.