Author
Raghu V. Prakash
Other affiliations: Indian Institute of Science, Indian Institutes of Technology, National Aerospace Laboratories
Bio: Raghu V. Prakash is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Paris' law & Ultimate tensile strength. The author has an hindex of 13, co-authored 105 publications receiving 707 citations. Previous affiliations of Raghu V. Prakash include Indian Institute of Science & Indian Institutes of Technology.
Papers published on a yearly basis
Papers
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TL;DR: In this article, the use of non-linear ultrasonic techniques for the characterization of material degradation in 99.98% pure copper due to high-temperature creep was described, where flat dog-bone-shaped specimens were subjected to constant load creep testing at different stress and temperature levels.
78 citations
TL;DR: In this article, the effect of shot peening and laser peening on the fatigue crack growth of Ti6Al4V alloy at a stress ratio R of 0.1 was investigated.
54 citations
TL;DR: In this article, a new nonlinear ultrasonic (NLU) technique for creep damage characterization is described, where dislocations are constrained between two quiescent lattice planes as defined by Cantrell.
53 citations
TL;DR: In this paper, the effect of three-dimensional loading on macroscopic fretting variables, such as contact tractions, slip and contact stresses over the dovetail interface, carried out using a threedimensional finite element method with frictional contact at the interface.
44 citations
TL;DR: In this paper, a nonlinear ultrasonic (NLU) harmonic generation system was used to characterize the fatigue damage in a flat hourglass, high strength Al-Cu-Zn-Mg alloy, AA7175-T7351 specimens.
Abstract: Nonlinear ultrasonic (NLU) harmonic generation system was used to characterize the fatigue damage in a flat hour-glass, high strength Al–Cu–Zn–Mg alloy, AA7175-T7351 specimens. Experiments were carried out to introduce controlled levels of fatigue damage under constant amplitude loading to determine the NLU response using surface acoustic wave (or Rayleigh mode) at regular intervals of fatigue life. The NLU parameter (A2/A12) plotted as a function of percentage of fatigue life shows two peaks for all the samples tested, independent of the amplitude of fatigue loading. The first peak appeared between 40%–50% of fatigue life and the second peak between 80%–90% of fatigue life. Among the two flat surfaces of the specimen, a higher nonlinearity response was observed on the surface which had the first crack initiation. The appearance of two peaks in the nonlinear response during fatigue damage progression is explained based on the dislocation dynamics and dislocation-crack interaction present in the specimens ...
42 citations
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TL;DR: In this article, the authors present a comprehensive review of the current state of knowledge of second harmonic generation (SHG) measurements, a subset of nonlinear ultrasonic non-destructive evaluation techniques.
Abstract: This paper presents a comprehensive review of the current state of knowledge of second harmonic generation (SHG) measurements, a subset of nonlinear ultrasonic nondestructive evaluation techniques. These SHG techniques exploit the material nonlinearity of metals in order to measure the acoustic nonlinearity parameter, $$\beta $$
. In these measurements, a second harmonic wave is generated from a propagating monochromatic elastic wave, due to the anharmonicity of the crystal lattice, as well as the presence of microstructural features such as dislocations and precipitates. This article provides a summary of models that relate the different microstructural contributions to $$\beta $$
, and provides details of the different SHG measurement and analysis techniques available, focusing on longitudinal and Rayleigh wave methods. The main focus of this paper is a critical review of the literature that utilizes these SHG methods for the nondestructive evaluation of plasticity, fatigue, thermal aging, creep, and radiation damage in metals.
271 citations
TL;DR: In this article, the microstructural response and grain subdivision process in commercially pure (CP) titanium subjected to multiple laser shock peening (LSP) impacts were investigated by means of optical microscopy (OM), scanning electron microscopy and transmission electron microscope (TEM) observations.
253 citations
TL;DR: The state-of-the-art in finite element analysis for plasticity-induced fatigue crack closure can be found in this article, where a comprehensive overview is presented, summarizing issues which must be considered and emphasizing potential difficulties.
200 citations
TL;DR: In this article, the influence of adhesive thickness and aluminum filler content on the mechanical performance of aluminum joints bonded by aluminum powder filled epoxy was determined by utilizing the single-lap shear test.
192 citations