- N D T abstracts N D T A b s t r a c t s a r e c o m p i l e d b y A E A T e c h n o l o g y N a t i o n a l N D T C e n t r e , H a r w e U , O x o n , O X 1 1 0 R A , U K . T h e e n t r i e s

a r e d r a w n f r o m o v e r 5 0 0 B r i t i s h a n d I n t e r n a t i o n a l p u b l i c a t i o n s . E a c h i s s u e c o n c e n t r a t e s o n o n e o r t w o s u b j e c t a r e a s .

T h e s u b j e c t s c o v e r e d i n p r e v i o u s i s s u e s f r o m F e b r u a r y 1 9 9 2 o n w a r d s a r e : A c o u s t i c emission monitoring of fatigue - 25(6); A c o u s t i c t e c h n i q u e s f o r a d h e s i v e b o n d e v a l u a t i o n - 25(2); A r t i f i c i a l

intelligence in N D T - 25(1); Characterization of ultrasonic transducers - 25(3); Magnet ic flux leakage - 26(1); Synthetic aperture signal processing - 26(3); Theory and modell ing of radiography - 25(4); Thermography o f composi tes - 26(2)

NDT in railways

53158 Kova/enko, A V Lebedev, A A H a r d n e s s tes t s o f we lded j o i n t s m ra i ls by t he a c o u s t i c m e t h o d R u s s m n Journal of NondestructLve Tes t ing , Vol 28, No. 12, pp. 786- 789 (Aug_ 1993)

The article presents the results of hardness tests of welded joints w~th an acoustic hardness tester based on the method of autoctrculauon of pulses By using the methods of planning experiments we obtained a model enabhng us to evaluate the influence of various technological factors m hardemng rads on the speed or ultrasound

52583 Telefunl~en Systemtechn,k AG A c o u s t i c de t ec t t on o f b r e a k s o r c r a c k s it: r a i l w a y t r a c k r e c o g n i s i n g c h a n g e in r e cep t t on o f a c o u s t i c s igna l t r a n s m i t t e d t h r o u g h ra i l s a n d t r a n s v e r s e s l e epe r s i m m e d i a t e l y European Patent No 514, 702 (25 Nov 1992)

52562 Saka, M, Yuasa, D, Abe, H., Sugino, K N o n d e s t r u c t i v e c h a r a c t e r i z a t i o n o f b i f u r c a t e d c r a c k by po ten t i a l d r o p t e c h n i q u e Nondes t ruc t ive Character iza t ion o f Mater ia ls V, Karu tzawa (Japan), 27- 30 May 1991 pp 61-72 Edi ted by T Ktshw, T. Saito, C. Ruud and R Green Iketam Science and T e c h n o l o g y Founda t ion (1993)

A method was presented for the nondestructive evaluauon of a crack bifurcated from a horizontal crack m a rml The method was based on the measurement of the difference and dlsmbution ofd_c elecmcal potential on the top surface of the raal F~rst, a problem of current flow m a plate, which contained horizontal and bifurcated cracks and was subjected to a umform current, was analyzed numerically by using a 2-D fimte element method Next, m order to character, ze the cracks m actual rad based on the 2-D numerical analys~s, a method was introduced for obtmmng a rectangular sectmn elecmcally equwalent to the section of actual rad. Finally. it was verified by experiments using rad specimens that the cracks were characterized quantitatively through the present numerical results together w~th the use of the equivalent secuon

52319 Valdunes I n t e r n a l u l t r a s o n i c i n spec t i on dev ice use fu l for r a i l w a y ax les c o n s i s t i n g of s e n s o r h e a d wi th e m i t t e r a n d d e t e c t o r u n i t s in spring- loaded support inserted into end of drilled component a n d g e n e r a t i n g t r a n s v e r s e s u r f a c e w a v e European Patent No 522,922 (13 Jan 1993)

52179 Lesyak, P S y s t e m of a u t o m a t i c u l t r a s o n i c q u a l i t y c o n t r o l o f r a i l r o a d ra i l s Russ ian Journal o f Nondes t ruc twe T es t mg , Vel 28, No. 7, pp. 383-388 (Mar. 1993)

The arhcle deals w,th the sounding procedure and the types of signal m rap~d ultrasomc quahty control of rails by the echo method. It explains the principles and system of computerized data processing w~th recording of the results on paper strip m real time

52039 Bambara. J E Acous t i c b e a r i n g defec t d e t e c t o r U.S Patent No 5. 150, 618 (29 Sep. 1992)

Tram wheel bea.nngs are acoustically scanned using the detector described in this patent m order to identify bearing defects, whde the tram moves through the scanning zone of a track Acousuc vibrations thus produced are transduced into elecmcal signals, which are processed to ~sola[e those relatmg to impact fr~:lueocies mdtcauve of beanng defects Whee ~ presence transducers on each track generate signals rod=caring the star', and fimsh of a wmdow surrounding an anticipated defect signal and register whether or not the signal occurs

51999 Mutton, P J , Langman. R A N o n - d e s t r u c t i v e r e s idua l s t r e s s m e a s u r e m e n t in r a i l w a y wheels , based on t he m a g n e t o m e c h a n i c a l e f fec t Aus t r ahan Institute of Non-Des t ruc twe T e s t m g National Conference , Melbourne (Aust raha) , 19-21 A u g 1991. 13pp

A I N D T (1991) Recent rese.arch suggests that the extent of plate dlscolourat=on may not

provide a rehable md=cauon of changes to the residual stress d~smbunon m freight car wheels The influence of a umaxlal stress field on the magnetic hysteresis behaviour of ferromagnetic materials forms the basts of the Wheel Stress Device (or Rotahon Rig)_ In the presence of such a stress field. a condmon of magneuc an=sotropy exists, such that dfffenng magnetic responses occur when ferromagnenc marenal is magneused either parallel or perpendicular to the dJrecuon of applied or residual stress, this =s known as the magnetomechan=cal effect The use of this effect for the measurement of residual stresses involves the apphcatlon of an external magnetic field, and the detection of an reduced voltage, the magnitude of which ,s related to the magnitude of residual stress In the presence of a btaxtal residual stress, the induced voltage =s proportional to the difference between pnncipal stresses (the stress difference)

51946 Schramm, R E.. Clark, A V ; Mttrakowc. D V_; Schaps, S.R U l t r a s o n i c m e a s u r e m e n t s o f r e s i dua l s t r e s s in r a i l r o a d wh ee l s Practical Apphca t ions o f RestduaJ Stress Techno logy , Ind tanapohs , Indiana (Umted States), 15-17 May 1991 pp 61-67. Edited by C. Rund ASM International (1991)

The ultrasonic probe here is an EMAT (electromagnetic-acoustic transducer). This type of transducer requires httle or no surface preparation and no acousuc couplant The system operates m a pulse- echo mode A short burst of shear honzontal waves travels through the nm thickness The rotauon of the EMAT determines the onentauon of the polanzauon vector. radml or ctrcumferenUal_ Precise timing of echoes m both directions reveals the degree of b=refrmgence Changes are due to both stress state and metallurgical texture Intual tests indicate it may be possible to separate these two The Federal Raalroad Admmtstrauon now has this instrumentation for field tests.

51820 Otsuka. H. Hzkosaka, H. Mtyatake. H_. Nakamura, S E s t i m a t i o n o f m a x i m u m s t r e s s in old r a i l w a y r ive ted l - g i r d e r b r i d g e s u s i n g acous t i c e m i s s i o n s i g n a l s Journal o f Acous t ic Emiss ion , Vol. 10, No 1-2, pp. S I 3 - S I 7 (1991-1992)

The apphcabduy of acoustic emission tests for the est~mauon of the ma.x~mum stresses m old riveted g~rder bndges was mvesugated A good agreement between experimental and theoretical values was found.

N D T & E In te rna t i ona l V o l u m e 26 N u m b e r 4 1 9 9 3 2 0 7