Automated resonant vibrating-reed analyzer apparatus for a non-destructive characterization of materials for industrial applications

Amadori, Stefano; Campari, Enrico Gianfranco; Fiorini, Anna Lisa; Montanari, Roberto; Pasquini, Luca; Savini, L.; Bonetti, E.

doi:10.1016/j.msea.2006.02.210

Cited by 52 publications

(42 citation statements)

References 9 publications

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“…3. Variation of the internal friction, Q −1 , and the normalized modulus of nanocrystalline MgH 2 during successive thermal runs [9] with visible dispersion in internal friction points Figure 4 indicates the smallest dispersion in internal friction values obtained from the advocated methods: the OMI, YM, and H-twin as a function of the number of oscillations, N osc . In general, dispersion in internal friction values varies as a function of theN osc , the signal-to-noise ratio, S/N, and the sampling frequency.…”

Section: Resultsmentioning

confidence: 99%

Critical Assessment Of The Issues In The Application Of Hilbert Transform To Compute The Logarithmic Decrement

Majewski

Magalas

2015

Archives of Metallurgy and Materials

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The parametric OMI (Optimization in Multiple Intervals), the Yoshida-Magalas (YM) and a novel Hilbert-twin (H-twin) methods are advocated for computing the logarithmic decrement in the field of internal friction and mechanical spectroscopy of solids. It is shown that dispersion in experimental points results mainly from the selection of the computing methods, the number of oscillations, and noise. It is demonstrated that conventional Hilbert transform method suffers from high dispersion in internal friction values. It is unequivocally demonstrated that the Hilbert-twin method, which yields a 'true envelope' for exponentially damped harmonic oscillations is superior to conventional Hilbert transform method. The 'true envelope' of free decaying strain signals calculated from the Hilbert-twin method yields excellent estimation of the logarithmic decrement in metals, alloys, and solids.Keywords: Logarithmic decrement, internal friction, mechanical spectroscopy, Hilbert transform, envelope, interpolated discrete Fourier transform DFT Do estymacji logarytmicznego dekrementu tłumienia w spektroskopii mechanicznej i w badaniach tarcia wewnętrznego ciał stałych zarekomendowano w pracy następujące metody obliczeniowe: metodę parametryczną OMI (Optimization in Multiple Intervals), metodę Yoshida-Magalas (YM) i nową metodę Hilbert-twin (H-twin). Wykazano, że dyspersja punktów eksperymentalnych logarytmicznego dekrementu tłumienia i tarcia wewnętrznego zdeterminowana jest przede wszystkim wyborem metody obliczeniowej, liczbą oscylacji i obecnością szumu w dyskretnych sygnałach odkształceń sprężystych badanych materiałów. Zastosowanie do obliczeń logarytmicznego dekrementu tłumienia klasycznej transformaty Hilberta powoduje bardzo dużą dyspersję punktów eksperymentalnych. W pracy wykazano, że metoda Hilbert-twin (transformata Hilberta zbliźniakowanego dyskretnego sygnału odkształceń sprężystych) po raz pierwszy umożliwia uzyskanie "prawdziwej obwiedni" wykładniczo tłu-mionych drgań harmonicznych próbki. Nowa metoda obliczeń "prawdziwej obwiedni" umożliwia bardzo dokładną estymację logarytmicznego dekrementu tłumienia w materiałach metalicznych i w ciałach stałych.

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Section: Resultsmentioning

confidence: 99%

Critical Assessment Of The Issues In The Application Of Hilbert Transform To Compute The Logarithmic Decrement

Majewski

Magalas

2015

Archives of Metallurgy and Materials

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“…Vickers microhardness (100 g/10 s) and tensile tests have been made to verify the effectiveness of the MA process. Tensile tests ( To determine the value of shear modulus G at increasing temperature, Mechanical Spectroscopy (MS) experiments with bar-shaped samples (length 60 mm, width 7 mm, thickness 0.5 mm) have been made by means of VRA 1604 apparatus (CANTIL Srl, Bologna, Italy) [23] with a heating rate of 1 • C/min.…”

Section: Methodsmentioning

confidence: 99%

Mechanical Characterization of a Nano-ODS Steel Prepared by Low-Energy Mechanical Alloying

Sanctis

Fava

Lovicu

et al. 2017

Metals

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An oxide dispersion strengthened (ODS) ferritic steel with nanometric grain size has been produced by low-energy mechanical alloying (MA) of steel powder (Fe-14Cr-1W-0.4Ti) mixed with Y 2 O 3 particles (0.3 wt %) and successive hot extrusion (HE). The material exhibits superior mechanical properties with respect to the unreinforced steel up to 400 • C; then such differences tend to progressively decrease and at 700 • C yield stress (YS) and ultimate tensile strength (UTS) values are very close. The microstructure and mechanical behaviour have been compared with those of ODS steels prepared by the most common process, high-energy MA, consolidation through hot isostatic pressing (HIP) or hot extrusion (HE), annealing around 1100 • C for 1-2 h. The main strengthening mechanisms have been examined and discussed to explain the different behaviour. In addition, heat treatments in the range 1050-1150 • C were carried out and a microstructural evolution with a relevant hardness decrease has been observed. TEM observations evidenced defect recovery and partial grain coarsening owing to the not perfectly homogeneous distribution of oxide particles.

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“…Damping and dynamic modulus measurements have been carried out on bar-shaped samples (60 mm × 7 mm × 0.5 mm) using the method of frequency modulation; the Vibrating Reed Apparatus VRA 1604 (CANTIL Srl, Bologna, Italy) employed in the experiments was previously described in detail in [27][28][29].…”

Section: Materials and Experimentalmentioning

confidence: 99%

Analysis of Relaxation Processes in HNS Due to Interstitial-Substitutional Pairs

Fava¹,

Montanari²,

Richetta³

et al. 2017

Metals

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Mechanical Spectroscopy (MS) tests have been performed on a high nitrogen (0.8 wt %) austenitic steel (HNS) with resonance frequencies in the range of kHz. Two sets of samples have been examined: the first set in an as-prepared condition, the second one submitted to a heat treatment of 2 h at 800 • C, which induces a discontinuous precipitation of Cr 2 N phase. In both sets, the damping spectrum shows a broad peak whose position and shape is changed by the precipitation of Cr 2 N phase. The results are explained by considering interstitial-substitutional (i-s) interactions.

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Automated resonant vibrating-reed analyzer apparatus for a non-destructive characterization of materials for industrial applications

Cited by 52 publications

References 9 publications

Critical Assessment Of The Issues In The Application Of Hilbert Transform To Compute The Logarithmic Decrement

Critical Assessment Of The Issues In The Application Of Hilbert Transform To Compute The Logarithmic Decrement

Mechanical Characterization of a Nano-ODS Steel Prepared by Low-Energy Mechanical Alloying

Analysis of Relaxation Processes in HNS Due to Interstitial-Substitutional Pairs

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