Nondestructive Testing. Powerful Resources To Serve Industry

Revue Aerospatiale - February 1994


Thanks to a giant scanner which has no rival in Europe, Aerospatiale Aquitaine inspects huge composite structures, mostly destined for launch into space. Technicians at Saint-Médard-en-Jalles 'journey' into the heart of matter to make sure all ballistic missile motor casings, nozzle throats, tanks for satellites, missile re-entry bodies and space-probe heat shields – equipment items and parts that must be 100% reliable – meet the highest quality standards.

Nondestructive testing techniques enable highly accurate pinpointing and identification of flaws like the separation of composite layers, loose bonds between different composite layers, material deficiencies, etc.

The originality of this method lies not only in its power but also in the sophisticated use of X-rays. A Saint-Médard technician explained that industrial tomography was akin to the scanners used for medical diagnosis. “The result is an accurate, clear image of a cross-section through an object. After X-ray scanning, a digital image showing local density levels point by point is obtained by a powerful computer-aided mathematical process. This method enables us to make multidirectional analyses and a very fine 3D reconstruction of the object. The slightest anomaly is then detectable.”

TV fluoroscopy – also used in medecine – is another valuable technique, its strong points being real-time observation and interactivity. The performance of conventional fluoroscopy is still somewhat mediocre as far as resolution and photophonic noise are concerned, but the use of an X-ray instrument with microfocus (on the order of 20 microns (1)) compensates for the low geometrical resolution by providing a highly magnified image.

As the front runner in these fields of technology, the Aerospatiale Group naturally wanted to share its know-how with manufacturers in other sectors of industry because tomography is particulary useful in the development of complex or costly items or of large parts measuring up to 6m tall and 2.35m across, and for checking them for possible flaws. One example of such 'technology transfer' concerned a cylinder head for a racing car.

By contrast, microfocus fluoroscopy is calibrated for small items and finds applications in the quality control of ball-bearings, gears and electrical or electronic components.

A new addition to the wide range of technologies used in non-destructive testing is Compton-ray (2) radiography – a fresh avenue of research for the Aquitaine laboratory.

(1) 1 micron = one millionth of a meter
(2) Named after the Nobel prize winning physicist.

EXPLOITATION

First Part (paragraphs 1, 2, 3)

1.1 Chercher dans le texte l'équivalent anglais de / Look through the text for the English equivalents to

par. 1
....................................................................................... tomographe
....................................................................................... gigantesque
....................................................................................... pénétrer au cœur de la matière
....................................................................................... lancements spatiaux
....................................................................................... corps de moteur
....................................................................................... col de tuyère
....................................................................................... corps de rentrée
....................................................................................... sonde spatiale
....................................................................................... bouclier thermique
....................................................................................... satisfaire à des normes
par. 2
....................................................................................... localisation
....................................................................................... défaut
....................................................................................... couche
....................................................................................... liaisonnement lâche
par. 3
....................................................................................... résider dans
....................................................................................... être apparenté à
....................................................................................... balayage par un faisceau de rayons X
....................................................................................... processus, opération
....................................................................................... la moindre anomalie

1.2 Répondre aux questions suivantes / Answer the following questions

1/ What three nondestructive techniques are mentioned in the text?


2/ What various composite structures are inspected by Aerospatiale technicians? What are they for? (§ 1)


3/ For what particular purpose is nondestructive testing used? (§ 2)


4/ What is industrial tomography akin to? (§ 3)


5/ How does an industrial scanner work? (§ 3)


6/ In what domain is industrial tomography particularly useful? (§ 5)

Second Part (paragraphs 4, 5, 6, 7)

2.1 Chercher dans le texte l'équivalent anglais / Look through the text for the English equivalents

par. 4
....................................................................................... la radioscopie télévisée
....................................................................................... en instantané
....................................................................................... comportement
....................................................................................... traditionnel
....................................................................................... quelque peu
....................................................................................... microfoyer
....................................................................................... compenser
....................................................................................... très grossi, à fort agrandissement
par. 5
....................................................................................... coureur de tête, précurseur
....................................................................................... domaine technologique
....................................................................................... partager son savoir-faire
....................................................................................... mise au point
....................................................................................... de x mètres de haut
....................................................................................... de x mètres de diamètre
....................................................................................... chercher d'éventuels défauts
....................................................................................... culasse
par. 6
....................................................................................... en comparaison
....................................................................................... roulement à billes
....................................................................................... engrenage
par. 7
....................................................................................... ajout
....................................................................................... gamme
....................................................................................... la radiographie à rayonnement Compton
....................................................................................... nouveau
....................................................................................... voie de recherche

2.2 Répondre aux questions suivantes / Answer the following questions

7/ How is fluoroscopy improved by the use of a microfocus? (§ 4)


8/ In what particular domain is microfocus fluoroscopy useful? (§ 7)


9/ What sort of equipment is inspected thanks to microfocus fluoroscopy? (§ 6)


10/ What are the strong points and weak points of TV fluoroscopy? (§ 4)


11/ Where does the name Compton-ray radiography come from? (§ 7 and Note)

Pour imprimer, passer par le mode paysage
To print, use landscape mode

© Christian Lassure - EFT

26 mars 2006 / March 26th, 2006

page d'accueil         sommaire textes          doc d'exploitation sous Word          corrige