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Rodolfo C C Flesch - One of the best experts on this subject based on the ideXlab platform.

  • nondestructive inspection of Metal Specimen using tone burst vibro acoustography
    Ultrasonics, 2021
    Co-Authors: Bruno Silva Marcio, Artur Antonio Seibert, Guilherme De Araujo Braz, Antonio Adilton Oliveira Carneiro, Rodolfo C C Flesch
    Abstract:

    Abstract Even though the pulse-echo ultrasonic technique is commonly used for the assessment of Metal structures, it has some inherent limitations. Vibro-acoustography (VA) is a relatively new ultrasonic technique which has demonstrated a great potential in revealing defects in objects, however it is traditionally used to analyze the integrity of Specimens made of low-stiffness materials. This work presents the evaluation of the performance of VA technique for the inspection of a steel structure, which was manufactured with defects of known geometry on its inner surface. All the inspection process was done automatically, from the data acquisition to the image processing for characterizing the defects. Experimental results show that VA was able to identify and characterize even the smallest defects in the structure, with a diameter of 2 mm. In addition, the results show that VA was able to characterize the artificial defects in the steel structure with almost the same errors as the traditional pulse-echo method, which indicates a potential use of VA in the inspection of materials with high mechanical stiffness.

  • enhanced damage measurement in a Metal Specimen through the image fusion of tone burst vibro acoustography and pulse echo ultrasound data
    Measurement, 2021
    Co-Authors: Bernardo Cassimiro Fonseca De Oliveira, Bruno Silva Marcio, Rodolfo C C Flesch
    Abstract:

    Abstract This paper proposes the use of image fusion for merging pulse-echo ultrasound and vibro-acoustography data of a Metallic sample with machined damages employing algebraic, Boolean, and principal component analysis fusion methods, to enhance the measurement results. Image fusion is an interesting alternative in this sense since it is easy to use, may provide efficient results, and its processing can be made a posteriori, without the need for raw data. After binarization with a combination of image processing tools, the damages were measured using Hough transform and the measurement errors related to their nominal values were analyzed. Two fusion rules of the algebraic fusion method provided the smallest measurement errors, with values 49% and 39% smaller than the ones of the ultrasound technique which provided the best results in isolation. The improvement in the results encourages the use of the proposed fusion methods in non-destructive testing applications.

  • quality assessment and deviation analysis of three dimensional geometrical characterization of a Metal pipeline by pulse echo ultrasonic and laser scanning techniques
    Measurement, 2019
    Co-Authors: Bruno Silva Marcio, Philipp Nienheysen, Daniel Habor, Rodolfo C C Flesch
    Abstract:

    Abstract Although ultrasonic-based techniques are the most widely used ones for the assessment of pipeline integrity they have some limitations, and alternative methods show potential to overcome them, such as laser scanning techniques. This paper presents the results of an experimental evaluation of pulse-echo ultrasonic and laser scanning techniques for pipeline inspection using a Metal Specimen which represents a damaged pipeline. Both techniques were able to detect all the defects on the inner surface of the Specimen, but the defect geometry was important to define the accuracy of each technique. For almost all the evaluated defects, the differences between the reference and the three-dimensional representations created from the experimental data showed that the ultrasonic technique presented errors with magnitude around 0.2 mm, which is in general half the error observed for the laser scanning technique. However, ultrasonic technique demanded 8 h for Specimen inspection, while laser technique required only 10 min.

Bruno Silva Marcio - One of the best experts on this subject based on the ideXlab platform.

  • nondestructive inspection of Metal Specimen using tone burst vibro acoustography
    Ultrasonics, 2021
    Co-Authors: Bruno Silva Marcio, Artur Antonio Seibert, Guilherme De Araujo Braz, Antonio Adilton Oliveira Carneiro, Rodolfo C C Flesch
    Abstract:

    Abstract Even though the pulse-echo ultrasonic technique is commonly used for the assessment of Metal structures, it has some inherent limitations. Vibro-acoustography (VA) is a relatively new ultrasonic technique which has demonstrated a great potential in revealing defects in objects, however it is traditionally used to analyze the integrity of Specimens made of low-stiffness materials. This work presents the evaluation of the performance of VA technique for the inspection of a steel structure, which was manufactured with defects of known geometry on its inner surface. All the inspection process was done automatically, from the data acquisition to the image processing for characterizing the defects. Experimental results show that VA was able to identify and characterize even the smallest defects in the structure, with a diameter of 2 mm. In addition, the results show that VA was able to characterize the artificial defects in the steel structure with almost the same errors as the traditional pulse-echo method, which indicates a potential use of VA in the inspection of materials with high mechanical stiffness.

  • enhanced damage measurement in a Metal Specimen through the image fusion of tone burst vibro acoustography and pulse echo ultrasound data
    Measurement, 2021
    Co-Authors: Bernardo Cassimiro Fonseca De Oliveira, Bruno Silva Marcio, Rodolfo C C Flesch
    Abstract:

    Abstract This paper proposes the use of image fusion for merging pulse-echo ultrasound and vibro-acoustography data of a Metallic sample with machined damages employing algebraic, Boolean, and principal component analysis fusion methods, to enhance the measurement results. Image fusion is an interesting alternative in this sense since it is easy to use, may provide efficient results, and its processing can be made a posteriori, without the need for raw data. After binarization with a combination of image processing tools, the damages were measured using Hough transform and the measurement errors related to their nominal values were analyzed. Two fusion rules of the algebraic fusion method provided the smallest measurement errors, with values 49% and 39% smaller than the ones of the ultrasound technique which provided the best results in isolation. The improvement in the results encourages the use of the proposed fusion methods in non-destructive testing applications.

  • quality assessment and deviation analysis of three dimensional geometrical characterization of a Metal pipeline by pulse echo ultrasonic and laser scanning techniques
    Measurement, 2019
    Co-Authors: Bruno Silva Marcio, Philipp Nienheysen, Daniel Habor, Rodolfo C C Flesch
    Abstract:

    Abstract Although ultrasonic-based techniques are the most widely used ones for the assessment of pipeline integrity they have some limitations, and alternative methods show potential to overcome them, such as laser scanning techniques. This paper presents the results of an experimental evaluation of pulse-echo ultrasonic and laser scanning techniques for pipeline inspection using a Metal Specimen which represents a damaged pipeline. Both techniques were able to detect all the defects on the inner surface of the Specimen, but the defect geometry was important to define the accuracy of each technique. For almost all the evaluated defects, the differences between the reference and the three-dimensional representations created from the experimental data showed that the ultrasonic technique presented errors with magnitude around 0.2 mm, which is in general half the error observed for the laser scanning technique. However, ultrasonic technique demanded 8 h for Specimen inspection, while laser technique required only 10 min.

Shigeru Kuramoto - One of the best experts on this subject based on the ideXlab platform.

  • study of the nanostructure of gum Metal using energy filtered transmission electron microscopy
    Acta Materialia, 2009
    Co-Authors: T Yano, Yasukazu Murakami, Daisuke Shindo, Shigeru Kuramoto
    Abstract:

    Abstract The nanostructure of Gum Metal, which has many anomalous mechanical properties, was investigated using transmission electron microscopy with energy filtering. A precise analysis of the weak diffuse electron scattering that was observed in the electron diffraction patterns of the Gum Metal Specimen revealed that Gum Metal contains a substantial amount of the nanometer-sized ω phase. The morphology of the ω phase appeared to have a correlation with the faulting in the {2 1 1} planes, which are one of the characteristic lattice imperfections of the Gum Metal Specimen. It is likely that the nanometer-sized ω phase may be a type of obstacle related to the restriction of the dislocation movement, which has been a significant problem in research on Gum Metal.

  • ebsp analysis on microstructure of gum Metal after plastic deformation
    Journal of The Japan Institute of Metals, 2005
    Co-Authors: Shigeru Kuramoto, Tadahiko Furuta, Junghwan Hwang, Kazuaki Nishino, Takashi Saito
    Abstract:

    EBSP (electron backscattering pattern) analysis was performed on microstructure of three β titanium alloy Specimens after cold working to study peculiar plastic behavior of the multifunctional alloy, Gum Metal. The Specimens employed were Ti-36%Nb-2%Ta-3%Zr-0.3%O (mass%) alloy (Gum Metal) and two reference alloys having lower and higher bcc phase stability than that of Gum Metal. Deformation twinning of {332} was observed in the Specimen with lower bcc stability, and dislocation glide in the Specimen with higher bcc stability. Orientation boundaries with rotation angle of 10-30 degrees were observed in Gum Metal Specimen, and they are considered to be identical to the giant planar faults which were observed in TEM in the previous study. It seems that the giant faults act as grain boundaries and numerous subgrains are generated in the later stage of plastic deformation. Amount of crystallographic rotation in deformed Gum Metal Specimens was very large, which implies that huge elastic energy was stored during plastic deformation.

J Fabis - One of the best experts on this subject based on the ideXlab platform.

  • on the use of the non direct tensile loading on a classical split hopkinson bar apparatus dedicated to sheet Metal Specimen characterisation
    International Journal of Impact Engineering, 2006
    Co-Authors: G Haugou, Eric Markiewicz, J Fabis
    Abstract:

    Abstract The facilities used to determine behaviour laws under dynamic loading are classified into two categories: impulsive and impact loading. For the first category, the properties of the industrial materials and their evolution at moderate strain rates range is generally obtained using split Hopkinson bars devices. Shear, tensile or compression strain modes, observed on crashed frameworks, are then applied on Specimens to establish classical plastic stress/strain relations. Tensile testing using a non direct loading configuration raise the problem of the set-up and the holding of sheet Specimens on the split Hopkinson bars devices, which generally induces impedance mismatches and perturbs the elastic pulses during their run through the Specimen assemblies. This paper presents an original tensile testing configuration required bonded sheet Metal Specimens on the external part of threaded sleeves. A test programme is carried out on two Metallic alloys (XES low carbon steel and 2024 T3 aluminium) at plastic strain rates between 180 and 440 s −1 . All results are compared with others experimental raw databases and validate this first stage of tensile loading.

Nobuyoshi Yanagida - One of the best experts on this subject based on the ideXlab platform.

  • PVP2008-61404 STUDY ON STRESS-STRAIN RELATION FOR TYPE 316L STAINLESS STEEL USING MIXED HARDENING LAW
    2020
    Co-Authors: Nobuyoshi Yanagida
    Abstract:

    ABSTRACT To determine stress-strain diagrams for a pipe butt joint of type 316L stainless steel, stress-strain diagrams for pipe Specimens subjected to monotonic uniaxial tensile load were measured. Tensile-test Specimens were extracted from the deposited Metal area, heat-affected zone, and parent-material area of the pipe butt joint. The Specimens of the depositedMetal area and the heat-affected zone were extracted from positions at the pipe inner surface, mid-thickness, and the pipe outer surface. The measurement temperatures were 20, 300, 600, and 800 o C. The measured stress-strain diagrams show that measured stress at the same given strain increases from measurement point on the outer surfer of the pipe to that on the inner surface. This stress increase is thought to be related to the number of thermal-load cycles used for the weld. The number of cycles at the pipe inner surface was greater than that at the pipe outer surface. To use the measured stress-strain diagrams in a thermal elasto-plastic analysis of welding residual stress and distortion, the measured diagrams for the deposited-Metalarea pipe Specimen and the parent-material-area pipe Specimen were fitted to calculated diagrams by using an isotropic/kinematic mixed hardening law. Material constants for approximating the stress-strain diagrams for the parentmaterial Specimen and deposited-Metal Specimen were determined. The calculated stress-strain diagrams derived from the isotropic/kinematic mixed hardening law show good agreement with the measured stress-strain diagrams

  • Study on Stress-Strain Relation for Type 316L Stainless Steel Using Mixed Hardening Law
    Volume 6: Materials and Fabrication Parts A and B, 2008
    Co-Authors: Nobuyoshi Yanagida
    Abstract:

    To determine stress-strain diagrams for a pipe butt joint of type 316L stainless steel, stress-strain diagrams for pipe Specimens subjected to monotonic uniaxial tensile load were measured. Tensile-test Specimens were extracted from the deposited Metal area, heat-affected zone, and parent-material area of the pipe butt joint. The Specimens of the deposited-Metal area and the heat-affected zone were extracted from positions at the pipe inner surface, mid-thickness, and the pipe outer surface. The measurement temperatures were 20, 300, 600, and 800°C. The measured stress-strain diagrams show that measured stress at the same given strain increases from measurement point on the outer surfer of the pipe to that on the inner surface. This stress increase is thought to be related to the number of thermal-load cycles used for the weld. The number of cycles at the pipe inner surface was greater than that at the pipe outer surface. To use the measured stress-strain diagrams in a thermal elasto-plastic analysis of welding residual stress and distortion, the measured diagrams for the deposited-Metal-area pipe Specimen and the parent-material-area pipe Specimen were fitted to calculated diagrams by using an isotropic/kinematic mixed hardening law. Material constants for approximating the stress-strain diagrams for the parent-material Specimen and deposited-Metal Specimen were determined. The calculated stress-strain diagrams derived from the isotropic/kinematic mixed hardening law show good agreement with the measured stress-strain diagrams.Copyright © 2008 by ASME