Showing papers by "Subhendu K. Datta published in 1993"
TL;DR: In this paper, the authors describe the results of experiments and calculations on the interaction of ultrasound with aluminum/aramid-epoxy composites (ARALLTM), a planar laminate of alternating constituent layers.
Abstract: This paper describes the results of experiments and calculations on the interaction of ultrasound with aluminum/aramid‐epoxy composites (ARALLTM), a planar laminate of alternating constituent layers. The plates have been investigated experimentally using fluid‐coupled leaky wave techniques, and theoretically using both a partial wave analysis and also a stiffness‐based numerical approach. Frequency zones of wave transmission and reflection, similar to those predicted for periodic media have been observed and modeled in the bilayered plates. The onset of this behavior has been simulated numerically by incrementally varying lamina properties starting from a homogeneous average value. It is demonstrated that the transmission zones arise from a consolidation or clustering of the uniform‐plate minima into frequency zones or bands, similar to Floquet wave behavior. Moreover, these bands, and the associated dispersion curves, are approximately constant in frequency, entirely unlike the behavior expected for a ho...
31 citations
TL;DR: In this article, a hybrid numerical method combining finite elements and the boundary integral representation is used to investigate the transient scattering of ultrasonic waves by a crack in a plate, and the results show that the location and depth of cracks have measurable effects on the surface responses in time and frequency domains.
Abstract: A hybrid numerical method combining finite elements and the boundary integral representation is used to investigate the transient scattering of ultrasonic waves by a crack in a plate. The incident wave models the guided waves generated by a steel ball impact on the plate. Two surface-breaking cracks and one subsurface crack are studied here. The results show that the location and depth of cracks have measurable effects on the surface responses in time and frequency domains. Also, the scattered fields have distinct differences in the three cases.
30 citations
01 Jan 1993
TL;DR: The use of fiber reinforced composite tubes in a number of aerospace structural applications is well established as mentioned in this paper, and the most serious hindrance to acceptance of composites, in general, is the need to certify non-destructively the integrity of the material.
Abstract: The current and proposed use of fiber reinforced composite tubes in a number of aerospace structural applications is well established. The most serious hindrance to acceptance of composites, in general, is the need to certify non-destructively the integrity of the material [1]. The modes of damage in a composite are varied and complex. Delaminations are particularly important, representing an advanced state of damage in the material [2,3].