EP0429446A1 - Essai non destructif de cables au moyen du procede par ondes vibratoires transversales - Google Patents

Essai non destructif de cables au moyen du procede par ondes vibratoires transversales

Info

Publication number
EP0429446A1
EP0429446A1 EP89900031A EP89900031A EP0429446A1 EP 0429446 A1 EP0429446 A1 EP 0429446A1 EP 89900031 A EP89900031 A EP 89900031A EP 89900031 A EP89900031 A EP 89900031A EP 0429446 A1 EP0429446 A1 EP 0429446A1
Authority
EP
European Patent Office
Prior art keywords
rope
waves
flaw
reflected
vibrational
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP89900031A
Other languages
German (de)
English (en)
Other versions
EP0429446A4 (en
Inventor
Hegeon Kwun
Gary L. Burkhardt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Southwest Research Institute SwRI
Original Assignee
Southwest Research Institute SwRI
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Southwest Research Institute SwRI filed Critical Southwest Research Institute SwRI
Publication of EP0429446A1 publication Critical patent/EP0429446A1/fr
Publication of EP0429446A4 publication Critical patent/EP0429446A4/en
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H63/00—Warning or safety devices, e.g. automatic fault detectors, stop-motions ; Quality control of the package
    • B65H63/06—Warning or safety devices, e.g. automatic fault detectors, stop-motions ; Quality control of the package responsive to presence of irregularities in running material, e.g. for severing the material at irregularities ; Control of the correct working of the yarn cleaner
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
    • G01H1/00—Measuring characteristics of vibrations in solids by using direct conduction to the detector
    • G01H1/04—Measuring characteristics of vibrations in solids by using direct conduction to the detector of vibrations which are transverse to direction of propagation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/04—Analysing solids
    • G01N29/045—Analysing solids by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/22—Details, e.g. general constructional or apparatus details
    • G01N29/227—Details, e.g. general constructional or apparatus details related to high pressure, tension or stress conditions
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/26—Scanned objects
    • G01N2291/262—Linear objects
    • G01N2291/2626—Wires, bars, rods

Definitions

  • the present invention relates to non-destructive testing of ropes, cables, and metal strands for flaws and tension.
  • NDE Non-destructive evaluation
  • NDE methods are in practice, while other methods have been proposed, but are not yet perfected. As will be shown hereinafter, no NDE method combines the advantageous features of the transverse impulse vibrational wave method disclosed in this application.
  • Electromagnetic NDE are presently the only type of non-visual method which is in current, widespread practice. Electromagnetic NDE methods are discussed in an article by Herbert R. Weischedel entitled "The Inspection of Wire Ropes in Service: A Critical Review" appearing in Materials Evaluation. 43, December 1986, pp 1592-1605. Electromagnetic NDE methods are used for: 1) localized fault detection
  • Electromagnetic NDE methods are limited to use on ferromagnetic materials, unlike transverse impulse vibrational wave method which may be performed on ferromagnetic or non-ferromagnetic materials as well as synthetic materials.
  • L.F. testing is based on the principal that broken wires in a wire rope made of ferromagnetic steels distort a magnetic flux passing the point of breakage causing magnetic flux leakage which is detectable in the area surrounding the rope.
  • L.F. testing is conducted by positioning a strong permanent or electromagnet in close proximity to a wire rope to be tested. As the rope passes the magnet or the magnet is moved along the length of the rope, a magnetic flux is initiated in the length of rope adjacent to the pole interspace of the magnet.
  • Differential sensing coils are positioned around the rope to detect magnetic flux leakage. Only major flaws, such as broken wires and severe corrosion pitting, are detected by L.F. testing, because only substantial changes in the magnetic flux leakage are detected by the differential sensors. Small flaws, or widely dispersed flaws, do not produce substantial and rapid magnetic flux leakage changes and are often missed using L.F. testing.
  • L.M.A. testing involves direct measurement of magnetic flux through a length of a wire rope. Variation in the magnetic flux through different portions of a single rope indicate a change in the cross-sectional area of the rope, which, in turn, indicates possible deterioration of the rope at areas of decreased cross-sectional area.
  • the electromagnetic methods require passing the entire length of a metallic rope to be tested through the testing apparatus or the testing apparatus be moved along the entire length of the rope.
  • Stress Wave Factor testing the necessity for access to the entire length of a rope reduces the utility of electromagnetic NDE methods.
  • Methods based on measuring vibrational frequencies of ropes and cables for determining tension are also known in the art.
  • U.S. Patent No. 456,099 issued to Arnold U.S. Patent No. 4,376,368 issued to Wilson, and U.S. Patent No. 4,158,962 issued to Conoval each related to calculating the tension on a rope or cable as a function of its fundamental frequency of vibration.
  • the equipment and methods shown in these patents and otherwise known in the art are not, however, suitable for practicing the non-tension related aspects of the transverse impulse vibrational wave method as described herein.
  • the present invention provides an apparatus and method utilizing pulsed, transverse, vibrational waves for non-destructive evaluation of cables, ropes, and metal strands for flaws and for tension.
  • the method is referred to as transverse impulse vibrational wave method.
  • the apparatus for transverse impulse vibrational wave method is designed for initiating a transverse vibrational wave motion in a rope, and for measuring the amplitude of and time intervals between the resulting waves as they travel though the rope.
  • The- apparatus comprises an exciting mechanism which applies a transverse impulsive force to the tested rope, a sensor which detects individual waves as they pass a particular point on the rope, a signal amplifier which raises the amplitude of the electrical signals form the sensor, a signal conditioner which filters unwanted signals from the sensor, and an oscilloscope which displays the measurements of the sensor in time versus amplitude units.
  • the apparatus optionally includes a computer and recorder or graphics printer.
  • the computer is for automating the measurements and calculations involved in detecting and locating flaws in a tested rope, as well as in determining the tension on a tested rope.
  • the recorder and graphics printer are for recording and producing a permanent record of the time/amplitude relationships of the vibrational waves as detected by the sensor.
  • the transverse impulse vibrational method for NDE of ropes is based on the fact that flaws in a rope partially reflect vibrational wave energy because of the acoustic impedance mismatches at the flaw locations. The wave is also reflected at the ends (or terminations) of the rope.
  • the sensor of the above- described testing apparatus produces corresponding electrical signals.
  • Calculations based on measurements of the time between the flaw signals and the end-reflected signals and on measurements of the relative amplitudes of the signals detected by the testing apparatus allow the user to locate rope flaws, to determine tension on the tested rope, and to measure the relative population of flaws in the tested rope as compared to a control rope sample.
  • Fig. 1 is a schematic depiction of the testing apparatus for transverse impulse vibrational wave method along with a rope for testing.
  • Fig. 2 shows a magnet/coil combination sensor
  • Fig. 3 shows the transverse impulse vibrational wave method testing apparatus set up for field testing a large guy wire.
  • Fig. 4 shows an example of an oscilloscope display obtained by using the transverse impulse vibrational method.
  • the present invention comprises a method and apparatus for non ⁇ destructive evaluation (NDE) of cables, synthetic ropes, and wire ropes for tension and flaws.
  • NDE non ⁇ destructive evaluation
  • the method will be referred to as "transverse impulse vibrational wave method” herein.
  • cable, synthetic rope, or wire rope will be referred to collectively as “rope” in most instances.
  • the testing apparatus is depicted schematically, and is referred to generally by the reference numeral 10.
  • the testing apparatus 10 is for detecting individual vibrational waves in a rope 12 and apprising a user of the presence, the relative amplitudes, and the sequential arrangement of the waves.
  • a rope 12 is shown in Figures 1, 2 and 3 to show the relationship of the testing apparatus' 10 components to a rope 12 which is to be tested.
  • Transverse Impulse Vibrational (TIV) wave method involves striking a rope
  • the testing apparatus 10 includes a striking mechanism 14 which consistently strikes the rope 12 with a predetermined force.
  • the striking mechanism 14 of the preferred embodiment is a solenoid 16 with its plunger 18 in a position for striking the rope 12 when the solenoid 16 is activated (see Figure 3).
  • Other designs for striking mechanisms 14 such as pneumatic devices or spring biased devices (not shown) would be equally acceptable.
  • a sensor 20 is included in the testing apparatus 10 for detecting individual vibrational waves in the rope 12 resulting from the impact from the striking mechanism 14.
  • the sensor 20 should be capable of discerning individual vibrational waves ranging in frequency up to approximately lKHz.
  • the particular method of detection for the sensor 20 is not important so long as the relative amplitudes and sequential arrangement of vibrational waves in the rope 12 may be derived from the sensor's 20 output.
  • the sensor 20 may measure the rope's 12 actual displacement, velocity of displacement, or acceleration of displacement.
  • Coil 22 is attached to the rope 12, and is placed between the positive pole 26 and the negative pole 28 of the magnet 24.
  • the leads 30 of the coil 22 are attached to the components of the testing apparatus 10 which process the sensor's 20 output. As the rope 12 vibrates, it causes the attached coil 22 to move relative to the field of the magnet 24. A voltage potential for each such movement is created, and the resulting electrical signals are detected and processed by the remaining components of the testing apparatus 10.
  • the testing apparatus 10 includes a signal amplifier
  • the signal amplifier 32 which is connected to the sensor 20.
  • the signal amplifier 32 receives the
  • the signal amplifier's 32 are higher, but directly proportional to the amplitudes of the electrical signals from the sensor 20.
  • the signal amplifier's 32 outputs are, therefore, proportional to the amplitudes of the actual vibrational waves in the rope 12.
  • the relative amplitudes of the vibrational waves in the rope 12 are important to TIV wave method analysis.
  • the testing apparatus 10 further includes a signal conditioner 34 which is connected to the signal amplifier 32 for receiving the amplified signals.
  • the signal conditioner 34 is a variable filter which filters signal frequencies from the signal amplifier 32 falling within a user-defined range. This allows a user to filter signals which are not useful for the test being conducted.
  • a digitizing oscilloscope 36 is believed to be the preferred recording/display device for the testing apparatus 10.
  • the oscilloscope 36 is connected to the signal conditioner 34 for receiving the signals from the signal conditioner 34.
  • the oscilloscope's 36 display 38 has a y-axis scale 40 measured in amplitude units, and an x-axis scale 42 measured in time units.
  • the oscilloscope 36 has calibration controls 43 for adjusting the display 38 to units appropriate to the particular rope 12 being tested.
  • the digitizing oscilloscope 36 not only gives a graphical representation of the relative amplitudes and sequential arrangement of the signals from the signal conditioner 34, and consequently those of the actual vibrational waves in the rope 12, but also records the signals for later re-display or computer analysis.
  • a trigger switch 44 activates the striking mechanism 14 and provides a synchronization signal to start the digitizing oscilloscope 36. Therefore, a user may simply throw the switch 44, and the striking mechanism 14 will strike the rope and the electronic components of the testing apparatus 10 will then process and record the resulting vibrational waves. If a computer 58 is used (to be discussed hereinafter) the computer 58 may be interfaced with the switch 44 and it may activate the components of the testing apparatus 10.
  • Transverse impulse vibrational wave method may be conducted through analysis of data which may be derived by the testing apparatus 10 as just described. Transverse impulse vibrational wave method is made possible because of the measurable effect that flaws and tension have on the vibration ⁇ al wave propagation properties of cables, ropes, and strands.
  • TIV wave method may be performed on ferromagnetic and non-ferromagnetic metallic materials as well as non-metallic materials alike. This gives TIV wave method a considerable utilitarian advantage over presently used NDE methods. It is of further importance that TIV wave method alone permits testing an entire length of a cable, rope, or strand from a single access point at one end. As previously mentioned, other NDE methods require passing the testing apparatus over the entire length of a test subject.
  • TIV wave method will normally be performed on cables, ropes, or metal strands which are in service as elevator cables, guy wires, or in similar high-stress and/or safety intensive applications.
  • the striking mechanism 14 is placed within a specified distance of the rope 12 which is to be tested. Because analysis of the test results are simplified by having the sensor 20 in close proximity to the striking mechanism 14, the striking mechanism 14 and the sensor 20 are mounted on a single support stand 46. The remaining components of the testing apparatus 10 are connected as discussed above.
  • a portable power supply 40 is shown in Figure 3 for use in areas where electricity for the testing apparatus 10 is not readily available.
  • the striking mechanism 14 and the sensor 20 should be placed near one end 50 of the rope 12. This simplifies analysis of tests results because a wave approaches and then is reflected by the end 50 of the rope 12 closest to the sensor 20. These waves will pass the sensor 20 a very short time apart. Therefore, the two passages appear, and can be treated as a single wave for purposes of TIV wave method.
  • vibrational waves created by the impact of the striking mechanism 14 will be referred to as a single wave in the following discussion.
  • the sensor 20 will produce an electrical signal in response to each vibrational wave of detectable amplitude which passes it.
  • Each electrical signal will have an amplitude proportional to the amplitude of its respective vibrational wave.
  • Signals from an end-reflected wave will, like the wave itself, have a larger amplitude than signals reflecting flaw-reflected waves.
  • Flaws which are large enough to provide reflected waves of measurable amplitude are referred to as "discrete flaws.” Flaws which are too small to reflect such waves are referred to as “non- discrete flaws" (not shown). While not individually detectable, the presence of non-discrete flaws may be recognized by methods which will be discussed hereinafter.
  • a discrete flaw is indicated in the oscilloscope display 38 as a low amplitude flaw signal 54 intervening higher amplitude end signals 56.
  • a flaw signal 54 does appear, calculations may be conducted to locate the discrete flaw 52 (shown in Figure 3) which it represents.
  • the pulse signal 55 is the wave directly resulting from the impact from the striking mechanism 14, and may be treated as an end signal 56.
  • each discrete flaw 52, the tension on the rope, and the presence of non-discrete flaws are determined by formulae, one or more of which require the following variables which may be derived from the oscilloscope display 38:
  • t r the time interval between adjacent end signals 56.
  • t f the time interval between an end signal 56 and the next subsequent flaw signal 54.
  • P j the amplitude of an end signal 56 at point i.
  • P. the amplitude of an end signal 56 at point j.
  • L ⁇ IJ the traveling distance of the wave between the two end signals shown by amplitudes P j and P j .
  • t r and t f are determined simply by measuring the number of time units between two adjacent end signals 56 as indicated by the x axis scale 42 in the oscilloscope display 38.
  • LJ may be derived by multiplying the length (L) of the rope 12 by twice the number of intervals between successive end signals 56 shown between points P j and P j on the display 38.
  • L the length of the rope being tested.
  • the length (L) may be determined by triangulation. If triangulation is not possible, the length (L) of the rope 12 must be determined by other means -- either by direct measurement, or by reference to blueprints, etc.
  • the mass per unit length (C) of the rope 12 may be acquired from the manufacturer of the rope 12, or may be determined by analysis of a rope sample (not shown) like the particular rope 12 which is to be tested.
  • T the tensile load on the rope 12.
  • alpha the attenuation coefficient of vibrational wave in the rope 12.
  • the distance (D) of a discrete flaw 52 from the end 50 of the rope 12 nearest the sensor 20 may be nearly approximated according to the following formula:
  • the flaw location aspect of the method permits substantial time sayings in locating a known discrete flaw 52 for determining the need, for the rope's 12 replacement. This is a substantial improvement over existing rope testing methods which require passing the testing apparatus over the entirety of the rope 12 to detect and to locate a flaw 52.
  • Propagation velocity (v) is a function of the tension (T) on the rope 12 according to the following formula:
  • transverse impulse vibrational wave method includes steps which, in some instances, provide an indicia of non-discrete flaws (not shown) in the rope 12. This aspect of the method is based upon the fact that the rate at which energy in a vibrating rope 12 is dissipated is directly proportional to the population of flaws in a rope 12.
  • Flaws whether discrete or non-discrete, interrupt the propagation of vibrational waves through the rope 12, and energy is thereby dissipated more rapidly than in a rope having fewer or no flaws.
  • the rate of energy dissipation in the rope 12 is shown by an attenuation coefficient (alpha).
  • the attenuation coefficient is calculated by the following formula:
  • the tested rope 12 shows a higher attenuation coefficient (alpha) than a control rope (not shown) known to be flawless, flaws in the rope 12 are indicated. 0
  • the variables necessary for calculating the attenuation coefficient are easily derived from the display 38 of the oscilloscope 36.
  • the computer 58 should be programed and equipped for the following tasks:
  • a recorder or graphics printer 60 should be attached to the computer 58.
  • the testing apparatus 10 and formulae just discussed provide a method of testing cable, synthetic rope, and metal strand which has not been previously known. No presently known testing apparatus or method is applicable to ferromagnetic and non-ferromagnetic materials, while at the same time permitting full-length testing from a single location on a cable, rope, or strand.
  • KEVLAR® will enable the use of these ropes for applications previously reserved to metallic cables because of inadequate testing procedures.
  • the ability to test the full length of a cable, rope, or strand will greatly reduce the time and expense involved in testing such things as elevator cables, antenna guy wires, crane support cables, and the like.

Abstract

Un procédé non destructif permet d'évaluer les défauts et la tension de cordes, câbles, et torons. Ce procédé permet de détecter des défauts en identifiant certaines configurations de distribution et d'amplitude d'ondes vibratoires résultant de l'application sur une éprouvette (12) d'un effort transversal. On calcule la tension sur ladite éprouvette (12) en mesurant la vitesse de propagation des ondes vibratoires à travers cette dernière. Un appareil (10) produit des ondes vibratoires (14) dans une éprouvette (12), mesure l'amplitude et la distribution temporelle des ondes (20), et affiche en vue de leur analyse les valeurs mesurées (38).
EP19890900031 1987-11-20 1988-11-21 Non-destructive evaluation of ropes by using transverse vibrational wave method Withdrawn EP0429446A4 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US12276387A 1987-11-19 1987-11-19
US122763 1987-11-20

Publications (2)

Publication Number Publication Date
EP0429446A1 true EP0429446A1 (fr) 1991-06-05
EP0429446A4 EP0429446A4 (en) 1991-10-16

Family

ID=22404623

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19890900031 Withdrawn EP0429446A4 (en) 1987-11-20 1988-11-21 Non-destructive evaluation of ropes by using transverse vibrational wave method

Country Status (3)

Country Link
EP (1) EP0429446A4 (fr)
CA (1) CA1294699C (fr)
WO (1) WO1989004960A1 (fr)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5024091A (en) * 1986-03-25 1991-06-18 Washington State University Research Foundation, Inc. Non-destructive evaluation of structural members
DE19531858B4 (de) * 1995-08-30 2005-06-09 Deutsche Telekom Ag Messverfahren für Abspannseile
WO2010129701A2 (fr) * 2009-05-05 2010-11-11 Actuant Corporation Evaluation sans contact de la propriété de propagation d'un signal acoustique d'une corde en fibre synthétique
ES2388295B2 (es) * 2010-07-20 2013-02-14 Manuel Córdoba Escobar Dispositivo de seguridad para la detección de defectos en cables de estructura metálica.
KR102084870B1 (ko) 2015-09-30 2020-03-04 샘슨 로프 테크놀로지스, 인크. 밧줄 제품의 비파괴 평가
CN106841385B (zh) * 2017-01-15 2019-05-07 长沙理工大学 基于声-超声的聚丙烯生产管道粉末粘附状态的检测方法
EP4081779A1 (fr) * 2019-12-24 2022-11-02 Samson Rope Technologies Systèmes et procédés d'évaluation de caractéristiques de corde
CN113884569A (zh) * 2021-08-12 2022-01-04 洛阳百克特科技发展股份有限公司 一种基于振动效应的钢丝绳损伤检测装置及其方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5984153A (ja) * 1982-11-05 1984-05-15 Sumitomo Metal Ind Ltd ライニング検査方法
US4519245A (en) * 1983-04-05 1985-05-28 Evans Herbert M Method and apparatus for the non-destructive testing of materials

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4408285A (en) * 1981-02-02 1983-10-04 Ird Mechanalysis, Inc. Vibration analyzing apparatus and method
CH656160A5 (de) * 1982-05-18 1986-06-13 Zellweger Uster Ag Verfahren und vorrichtung zur ueberwachung von einzeladern bei verseilprozessen.
US4567764A (en) * 1983-12-27 1986-02-04 Combustion Engineering, Inc. Detection of clad disbond

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5984153A (ja) * 1982-11-05 1984-05-15 Sumitomo Metal Ind Ltd ライニング検査方法
US4519245A (en) * 1983-04-05 1985-05-28 Evans Herbert M Method and apparatus for the non-destructive testing of materials

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, vol. 8, no. 196 (P-299)[1633], 8th September 1984; & JP-A-59 84 153 (SUMITOMO) 15-05-1984 *
See also references of WO8904960A1 *

Also Published As

Publication number Publication date
EP0429446A4 (en) 1991-10-16
WO1989004960A1 (fr) 1989-06-01
CA1294699C (fr) 1992-01-21

Similar Documents

Publication Publication Date Title
US4979125A (en) Non-destructive evaluation of ropes by using transverse impulse vibrational wave method
US5821430A (en) Method and apparatus for conducting in-situ nondestructive tensile load measurements in cables and ropes
US5457994A (en) Nondestructive evaluation of non-ferromagnetic materials using magnetostrictively induced acoustic/ultrasonic waves and magnetostrictively detected acoustic emissions
US6424150B2 (en) Magnetostrictive sensor rail inspection system
US6192758B1 (en) Structure safety inspection
US5456113A (en) Nondestructive evaluation of ferromagnetic cables and ropes using magnetostrictively induced acoustic/ultrasonic waves and magnetostrictively detected acoustic emissions
US5520052A (en) Method and apparatus for determining material structural integrity
US4342229A (en) Apparatus and method for the non-destructive testing of the physical integrity of a structural part
EP1236996A1 (fr) Dispositif de controle de structure
KR100573736B1 (ko) 비틀림파를 발생 및 측정할 수 있는 트랜스듀서와 이를이용한 이상진단 장치 및 방법
JPH02212734A (ja) 構造部材の構造的完全性変化を検出する装置および方法
WO2002079775A1 (fr) Procede et dispositif pour detecter des dommages dans des materiaux ou dans des objets
US20130111999A1 (en) Method and device for non-destructive material testing by means of ultrasound
US5714688A (en) EMAT measurement of ductile cast iron nodularity
Ohtsu et al. Principles of the acoustic emission (AE) method and signal processing
JP2019132658A (ja) Ｐｃグラウト充填状態の非破壊診断方法
CN114486577A (zh) 一种uhpc的i型动态断裂韧度的测试试样、装置及方法
US4380931A (en) Apparatus and method for quantitative nondestructive wire testing
EP0429446A1 (fr) Essai non destructif de cables au moyen du procede par ondes vibratoires transversales
GB2383413A (en) Detecting rail defects using acoustic surface waves
US4231259A (en) Method and apparatus for non-destructive evaluation utilizing the internal friction damping (IFD) technique
JPH0511895B2 (fr)
US2656714A (en) Method and apparatus for nondestructive investigation of magnetostrictive solids
JP2002148244A (ja) コンクリート構造物の調査・診断方法
WO1999053282A1 (fr) PROCEDE ET APPAREIL PERMETTANT D'EFFECTUER IN-SITU DES MESURES NON DESTRUCTRICES D'EFFORT DE TRACTION DANS DES CABLES ET DES cordes

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19900824

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

A4 Supplementary search report drawn up and despatched

Effective date: 19910826

AK Designated contracting states

Kind code of ref document: A4

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19930602