FR2747472A1 - Fatigue control system particularly for textile cables - Google Patents
Fatigue control system particularly for textile cables Download PDFInfo
- Publication number
- FR2747472A1 FR2747472A1 FR9604573A FR9604573A FR2747472A1 FR 2747472 A1 FR2747472 A1 FR 2747472A1 FR 9604573 A FR9604573 A FR 9604573A FR 9604573 A FR9604573 A FR 9604573A FR 2747472 A1 FR2747472 A1 FR 2747472A1
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- Prior art keywords
- cable
- modulus
- elasticity
- sensors
- propagation
- 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.)
- Granted
Links
- 239000004753 textile Substances 0.000 title claims description 7
- 238000000034 method Methods 0.000 claims abstract description 10
- 238000005259 measurement Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 230000006870 function Effects 0.000 description 2
- 239000004973 liquid crystal related substance Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 210000001015 abdomen Anatomy 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000013479 data entry Methods 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/30—Investigating strength properties of solid materials by application of mechanical stress by applying a single impulsive force, e.g. by falling weight
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/36—Textiles
- G01N33/365—Filiform textiles, e.g. yarns
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/0069—Fatigue, creep, strain-stress relations or elastic constants
- G01N2203/0073—Fatigue
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/0069—Fatigue, creep, strain-stress relations or elastic constants
- G01N2203/0075—Strain-stress relations or elastic constants
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/022—Environment of the test
- G01N2203/0244—Tests performed "in situ" or after "in situ" use
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/0658—Indicating or recording means; Sensing means using acoustic or ultrasonic detectors
Landscapes
- Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Biochemistry (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Analytical Chemistry (AREA)
- Textile Engineering (AREA)
- Food Science & Technology (AREA)
- Medicinal Chemistry (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
Description
PROCÉDÉ ET DISPOSITIF DE CONTROLE DE FATIGUE D'UN CÂBLE DE
MANUTENTION
La présente invention a pour objet un procédé et un dispositif de contrôle de fatigue d'un câble de manutention destiné en particulier, mais non exclusivement aux câbles textiles.METHOD AND DEVICE FOR CONTROLLING FATIGUE OF A CABLE
HANDLING
The subject of the present invention is a method and a device for monitoring the fatigue of a handling cable intended in particular, but not exclusively, for textile cables.
On sait que de tels câbles passent généralement sur des poulies et qu'ils sont soumis à une usure notable. Afin d'éviter tout accident, il est souhaitable de déterminer des critères de dépose indiquant la nécessité de remplacer le câble usagé par un câble neuf.It is known that such cables generally pass over pulleys and that they are subjected to significant wear. In order to avoid any accident, it is desirable to determine removal criteria indicating the need to replace the used cable with a new cable.
Avec les câbles métalliques le contrôle peut être effectué par voie électrique (généralement par mesure de courants de
FOUCAULT), soit encore par un examen visuel, les brins extérieurs du câble soumis aux plus grandes extensions se rompant avant les brins intérieurs. Tel n'est pas le cas dans les câbles textiles dans lesquels l'usure n'est pas apparente. I1 a déjà été proposé d'inclure à l'intérieur d'un câble textile un fil de carbone. La conductibilité de celui-ci rend possible une mesure de continuité électrique.With metallic cables, the control can be carried out electrically (generally by measuring currents of
FOUCAULT), or again by a visual examination, the outer strands of the cable subjected to the greatest extensions breaking before the inner strands. This is not the case in textile cables in which wear is not apparent. It has already been proposed to include a carbon thread inside a textile cable. The conductivity of the latter makes it possible to measure electrical continuity.
mais ce contrôle reste en grande partie aléatoire. Or, pour définir des critères de dépose, il est nécessaire de pouvoir contrôler l'usure du câble.but this control remains largely random. However, to define removal criteria, it is necessary to be able to control the wear of the cable.
La présente invention a pour objet de pallier cet inconvénient et de permettre de mesurer la fatigue d'un câble textile par un contrôle non destructif et d'en déduire la nécessité de son remplacement.The object of the present invention is to overcome this drawback and to make it possible to measure the fatigue of a textile cord by non-destructive testing and to deduce the need for its replacement therefrom.
On sait que les câbles textiles peuvent transmettre des ondes longitudinales ou transversales. Une onde est dite transversale lorsque la direction de vibration des
particules est perpendiculaire à la direction de propagation de l'onde. C'est ce qui se passe dans les instruments de musique où à la suite d'une excitation les cordes présentent des noeuds et des ventres de vibrations se traduisant par l'émission d'un son. Dans ce cas, la vitesse de propagation est une fonction de la tension de la corde.It is known that textile cables can transmit longitudinal or transverse waves. A wave is said to be transverse when the direction of vibration of the
particle is perpendicular to the direction of wave propagation. This is what happens in musical instruments where, following an excitation, the strings present knots and bellies of vibrations resulting in the emission of a sound. In this case, the speed of propagation is a function of the tension of the string.
Selon l'invention, le procédé de contrôle d'usure d'un câble est caractérisé en ce qu'il consiste à mesurer le module d'élasticité de celui-ci.According to the invention, the method of checking the wear of a cable is characterized in that it consists in measuring the modulus of elasticity of the latter.
On a en effet constaté au cours d'essais en traction de câble neufs et usagés que le module d'élasticité variait au cours de l'utilisation d'un câble, son module d'élasticité donnant une bonne image de son usure.It was in fact observed during tensile tests of new and used cables that the modulus of elasticity varied during the use of a cable, its modulus of elasticity giving a good image of its wear.
Selon une autre caractéristique de l'invention, le procédé est caractérisé en ce que le module d'élasticité E est calculé selon la formule
E= V2.p dans laquelle V est la vitesse de propagation d'une onde longitudinale dans un câble sous tension et p la masse volumique du câble.According to another characteristic of the invention, the method is characterized in that the modulus of elasticity E is calculated according to the formula
E = V2.p where V is the propagation speed of a longitudinal wave in a live cable and p the density of the cable.
Dans le cas d'une onde longitudinale, la vibration des particules est parallèle à la direction de propagation de l'onde. L'équation de la vitesse de propagation longitudinale est différente de l'équation de la vitesse de propagation des ondes transversales. Selon l'invention, on provoque un impact longitudinal sur le câble pour mesurer sa vitesse de propagation et en déduire le module d'élasticité caractéristique de la fatigue. In the case of a longitudinal wave, the vibration of the particles is parallel to the direction of propagation of the wave. The equation for the longitudinal propagation velocity is different from the equation for the propagation velocity of transverse waves. According to the invention, a longitudinal impact is caused on the cable in order to measure its propagation speed and to deduce therefrom the elastic modulus characteristic of fatigue.
La présente invention vise également un dispositif de mesure de la vitesse d'une onde dans un câble caractérisé en ce qu'il comprend deux capteurs chacun étant relié par un amplificateur à un oscillographe.The present invention also relates to a device for measuring the speed of a wave in a cable, characterized in that it comprises two sensors each being connected by an amplifier to an oscillograph.
I1 est ainsi possible, par une mesure très simple et non destructive, de mesurer la fatigue d'un câble, même lorsque celui-ci est en service. It is thus possible, by a very simple and non-destructive measurement, to measure the fatigue of a cable, even when the latter is in service.
D'autres caractéristiques et avantages de l'invention apparaîtront au cours de la description qui va suivre de modes particuliers de réalisation, donnés uniquement à titre d'exemples non limitatifs, en regard des dessins qui représentent
- La figure 1, un schéma de montage permettant de
déterminer la vitesse de propagation d'une onde dans un
câble;
- la figure 2, un schéma des signaux pouvant être
observés
- la figure 3, une représentation des temps en fonction de
la distance séparant les deux capteurs;
- la figure 4, un schéma par blocs d'un appareil portable
de mesure d'un module d'élasticité d'un câble.Other characteristics and advantages of the invention will become apparent during the following description of particular embodiments, given solely by way of nonlimiting examples, with reference to the drawings which represent
- Figure 1, an assembly diagram making it possible to
determine the propagation speed of a wave in a
cable;
- Figure 2, a diagram of the signals that can be
observed
- Figure 3, a representation of the times as a function of
the distance separating the two sensors;
- figure 4, a block diagram of a portable device
for measuring a modulus of elasticity of a cable.
Pour déterminer la vitesse V de propagation il suffit de déterminer le temps de propagation entre deux points fixes.To determine the propagation speed V, it suffices to determine the propagation time between two fixed points.
On dispose pour ce faire deux mors Al, A2 sur chacun desquels on fixe un accéléromètre. Un anneau métallique M est fixé sur le câble en amont du premier accéléromètre.To do this, two jaws A1, A2 are available on each of which an accelerometer is fixed. A metal ring M is fixed on the cable upstream of the first accelerometer.
C'est sur l'anneau M que l'impact est effectué manuellement, parallèlement à la direction longitudinale du câble C, à l'aide d'un maillet en bois ou plastique pour éviter des vibrations parasites. Le câble est maintenu sous tension constante car la charge appliquée intervient sur les résultats de la mesure. Par contre, les points d'application de la tension n'interviennent pas sur les résultats.It is on the ring M that the impact is carried out manually, parallel to the longitudinal direction of the cable C, using a wooden or plastic mallet to avoid parasitic vibrations. The cable is kept under constant tension because the applied load affects the measurement results. On the other hand, the points of application of the tension do not intervene on the results.
La mesure consiste à déterminer le temps de parcours de l'onde entre les deux accéléromètres A1, A2. Chaque accéléromètre émet un signal qui est amplifié dans les amplificateurs 3 et 4 et transmis, après amplification sur les bornes d'entrées de l'oscilloscope 5. Les signaux apparaissant sur l'écran de celui-ci sont déphasés sur l'axe des temps (fig.2), le retard correspondant au temps de propagation de l'onde crée par l'impact sur la distance A1-
A2. On peut lire, grâce aux curseurs de l'oscilloscope, deux temps, respectivement le temps T1 à la base et le temps T2 au sommet. On se réfère, de préférence au temps T2 qui est plus accessible. La vitesse de propagation est l'inverse de la pente de la droite T2 = f(A1-A2) Afin d'obtenir des résultats plus cohérents, on répète cette mesure sur plusieurs distances A1-A2. Connaissant la vitesse de propagation, on en déduit le module d'élasticité du câble et celui-ci peut être lu directement sur l'appareil si la masse volumique du câble a été introduite en mémoire. Pour éviter des anomalies locales éventuelles de structure, la même mesure peut être effectuée sur des tronçons différents de même longueur, la distance des capteurs restant inchangée.The measurement consists in determining the travel time of the wave between the two accelerometers A1, A2. Each accelerometer emits a signal which is amplified in amplifiers 3 and 4 and transmitted, after amplification on the input terminals of oscilloscope 5. The signals appearing on the latter's screen are phase-shifted on the time axis. (fig. 2), the delay corresponding to the propagation time of the wave created by the impact on the distance A1-
A2. We can read, thanks to the oscilloscope cursors, two times, respectively the time T1 at the base and the time T2 at the top. Reference is preferably made to the time T2 which is more accessible. The propagation speed is the inverse of the slope of the line T2 = f (A1-A2) In order to obtain more consistent results, this measurement is repeated over several distances A1-A2. Knowing the propagation speed, the elastic modulus of the cable can be deduced therefrom and this can be read directly on the device if the density of the cable has been entered in memory. To avoid possible local structural anomalies, the same measurement can be carried out on different sections of the same length, the distance from the sensors remaining unchanged.
La mesure qui vient d'être décrite correspond à une installation expérimentale. Pratiquement, il n'est pas nécessaire de voir les signaux et une machine portable comportant un clavier d'entrée de données, un microprocesseur sur lequel sont appliqués les signaux permet un affichage direct sur un écran à cristaux liquides du module d'élasticité. Un tel appareil est schématisé sur la figure 4. Il se compose de deux entrées Al, A2, qui au cours des opérations sont connectées aux accéléromètres du même nom, reliées à un étage amplificateur 10 dont les sorties sont connectées à un microprocesseur 11 incluant une base de temps. Le microprocesseur est par ailleurs connecté à un étage d'entrée 12 permettant d'introduire en mémoire la masse volumique et la distance A1-A2. La sortie de l'étage 11 est connectée à un dispositif d'affichage 13, par exemple du type à cristaux liquides. Le microprocesseur, par un échantillonnage des entrées, A1 et A2 calcule automatiquement le module d'élasticité et l'affiche sur le tableau 13. Cet appareil peut être étalonné sur des câbles existants dont les caractéristiques sont connues.The measure which has just been described corresponds to an experimental installation. Practically, it is not necessary to see the signals and a portable machine having a data entry keyboard, a microprocessor on which the signals are applied allows a direct display on a liquid crystal screen of the modulus of elasticity. Such a device is shown diagrammatically in FIG. 4. It consists of two inputs A1, A2, which during operations are connected to the accelerometers of the same name, connected to an amplifier stage 10 whose outputs are connected to a microprocessor 11 including a time base. The microprocessor is also connected to an input stage 12 making it possible to enter the density and the distance A1-A2 into memory. The output of stage 11 is connected to a display device 13, for example of the liquid crystal type. The microprocessor, by sampling the inputs, A1 and A2, automatically calculates the modulus of elasticity and displays it on table 13. This device can be calibrated on existing cables whose characteristics are known.
On a comparé par le procédé selon l'invention des câbles de type Z neufs et usagés par le procédé et avec le dispositif selon l'invention.New and used Z-type cables were compared by the method according to the invention by the method and with the device according to the invention.
Les résultats sont les suivants
V m/s E GPa
CÂBLE Z NEUF 7685 61
CÂBLE Z usagé 100.000 cycles 6830 48 sous 1918 daN
On remarquera que le module d'élasticité varie en fonction de l'usure du câble. Le module du câble Z usagé varie par rapport à celui du câble neuf.The results are as follows
V m / s E GPa
Z CABLE NEW 7685 61
CABLE Z used 100,000 cycles 6830 48 under 1918 daN
It will be noted that the modulus of elasticity varies according to the wear of the cable. The modulus of the used Z cable varies from that of the new cable.
Il va de soi que de nombreuses variantes peuvent être apportées, notamment par substitution de moyens techniques équivalents, sans sortir pour cela du cadre de l'invention. It goes without saying that numerous variants can be made, in particular by substitution of equivalent technical means, without thereby departing from the scope of the invention.
Claims (4)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9604573A FR2747472B1 (en) | 1996-04-12 | 1996-04-12 | METHOD AND DEVICE FOR CONTROLLING THE FATIGUE OF A HANDLING CABLE |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9604573A FR2747472B1 (en) | 1996-04-12 | 1996-04-12 | METHOD AND DEVICE FOR CONTROLLING THE FATIGUE OF A HANDLING CABLE |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| FR2747472A1 true FR2747472A1 (en) | 1997-10-17 |
| FR2747472B1 FR2747472B1 (en) | 2002-08-02 |
Family
ID=9491137
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| FR9604573A Expired - Fee Related FR2747472B1 (en) | 1996-04-12 | 1996-04-12 | METHOD AND DEVICE FOR CONTROLLING THE FATIGUE OF A HANDLING CABLE |
Country Status (1)
| Country | Link |
|---|---|
| FR (1) | FR2747472B1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102004063709B3 (en) * | 2004-12-28 | 2006-07-13 | Abus Kransysteme Gmbh | Cable service life estimation method for use with cable used in a conveying arrangement or with lifting gear, wherein individual cable segment loads are determined and used in conjunction with an overall load configuration |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2152088A (en) * | 1983-12-20 | 1985-07-31 | Bridon Plc | Detection of deterioration in rope |
| JPS6161027A (en) * | 1984-09-03 | 1986-03-28 | Bridgestone Corp | Measuring instrument for tension of wire body |
| US5174160A (en) * | 1989-09-19 | 1992-12-29 | Japan Atomic Energy Research Institute | Method of diagnosing electric wires and cables for deterioration of their polymer-insulation and a measuring apparatus used therefor |
| DE4421232A1 (en) * | 1993-06-21 | 1995-04-20 | Barmag Barmer Maschf | Method for determining the quality of a thread |
-
1996
- 1996-04-12 FR FR9604573A patent/FR2747472B1/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2152088A (en) * | 1983-12-20 | 1985-07-31 | Bridon Plc | Detection of deterioration in rope |
| JPS6161027A (en) * | 1984-09-03 | 1986-03-28 | Bridgestone Corp | Measuring instrument for tension of wire body |
| US5174160A (en) * | 1989-09-19 | 1992-12-29 | Japan Atomic Energy Research Institute | Method of diagnosing electric wires and cables for deterioration of their polymer-insulation and a measuring apparatus used therefor |
| DE4421232A1 (en) * | 1993-06-21 | 1995-04-20 | Barmag Barmer Maschf | Method for determining the quality of a thread |
Non-Patent Citations (1)
| Title |
|---|
| PATENT ABSTRACTS OF JAPAN vol. 010, no. 225 (P - 484) 6 August 1986 (1986-08-06) * |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2747472B1 (en) | 2002-08-02 |
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