• Aucun résultat trouvé

ELASTIC-PLASTIC WAVES IN UV0,2 URANIUM ALLOY

N/A
N/A
Protected

Academic year: 2021

Partager "ELASTIC-PLASTIC WAVES IN UV0,2 URANIUM ALLOY"

Copied!
6
0
0

Texte intégral

(1)

HAL Id: jpa-00224353

https://hal.archives-ouvertes.fr/jpa-00224353

Submitted on 1 Jan 1984

HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

ELASTIC-PLASTIC WAVES IN UV0,2 URANIUM ALLOY

H. Bernier, P. Lalle

To cite this version:

H. Bernier, P. Lalle. ELASTIC-PLASTIC WAVES IN UV0,2 URANIUM ALLOY. Journal de

Physique Colloques, 1984, 45 (C8), pp.C8-273-C8-277. �10.1051/jphyscol:1984851�. �jpa-00224353�

(2)

J O U R N A L DE PHYSIQUE

Colloque C8, supplément a u n O 1 l , Tome 45, novembre 1984 page C8-273

ELASTIC-PLASTIC W A V E S I N UVo,2 URANIUM A L L O Y

H. Bernier and P. Lalle*

C.E. A., Centre d 'Etudes de Limeil-Valenton, B . P . n 27, 94190 Vi,iZZeneuve-Saint-Georges, France

*c.E.A., Centre drEtudes S c i e n t i f i q u e s e t Techniques d'Aquitaine, B.P. n o 2, Le Barp, 33830 Belin-Beliet, Franee

Résumé - Les ondes de d e t e n t e i s s u e s de l a f a c e a r r i s r e d ' u n p r o j e c t i l e , l o r s d e son impact s u r une c i b l e de même n a t u r e s o n t u t i l i s ê e s pour d é t e r m i n e r c e r t a i n e s c a r a c t é r i s t i q u e s dynamiques de l ' a l l i a g e d ' u r a n i u m UVo,2.

Dans l e domaine de p r e s s i o n c o u v e r t e x p @ r i m e n t a l e n e n t ( ~ 2 9 G P a ) , 1 a v i t e s s e au p r é c u r s e u r é l a s t i q u e e s t d ' e n v i r o n 3,45 kmis, e t l a l i m i t e é l a s t i q u e a ' h u g o n i o t e s t de 1,15 GPa.

La b a i s s e de p r e s s i o n d e r r i s r e 1 'onde de choc d ' i n t e n s i t é 20GPa (29GPa) débüte p a r une onde quasi é l a s t i q u e d o n t l a v i t e s s e e s t de 3,9 km/s

(4,2 km/s) e t l e s a u t de p r e s s i o n de 3GPa (3,7GPa).

A b s t r a c t

-

Release waves cûminy f r o m t h e back f a c e o f an u r a n i u a a l l o y p r o z e c t i l e i n a symmetric c o l l i s i o n a r e used t o e s t i a a t e sorne dynaiïiic c n a r a c t e r i s s i c s o f t h i s m a t e r i a l .

I n t h e p r e s s u r e range e x p e r i n i e i i t a l l y covered ( 5 2Y GPa) t h e v e l o c i t y o f t h e e l a s t i c p r e c u r s o r i s a b w t 3,4.5 km/s, and t h e h u g o n i o t e l a s t i c l i m i t (HEL) -is 1,15GPa.

The p r e s s u r e decrease b e l i i n d t h e 20GPa 129GPa) shocl< wave b e g i n s w i t h a q l i a s i - e l a s t i c wave wliich v e i o c i t y i s 3,9 km/s 14,2 ::a/s), ana p r e s s u r e jumy o f 3GPa i3,7GPa).

Using an UVo,2 p r o j e c t i l e launched on an UVo,2 t a r g e t showing two s t e p s on i t s Face o p p o s i t e t~ t h e irapact one, cve r e c o r d , w i t h a P e r o t Fabry i n t e r f e r o r n e t e r , t h e v e l o c i t y o f t h e boundary s u r f a c e between t h e s e t v o steps and a t r a n s p a r e n t : a a t e r i a i ( w a t e r ) .

T n i s set-up i s i n t e r m e d i a t e betweeri t h o s e r e c e n t l y p r e s e n t e d by R. G. Mc Queen e t a i

Il]-

and C.E. M o r r i s e t a l [%]

From t h e s e r e c o r d s we deduce f o r t ~ o d i f f e r e n t t h i c k n e s s e s o f t h e t a r g e t t h e v e l o c i t i e s o f t h e e i a s t i c - p l a s t i c r e l e a s e waves c o n i n g f r o m t h e bac/< f a c e o f t h e p r o j e c t i l e .

p r o j e c t i l e t a r g é t window

1 a

Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1984851

(3)

CS-274 JOURNAL DE PHYSIQUE

The shock inpeaance o f t n e t a r g e t b e i n g o r e a t e r t h a n t h a t o f t h e water, t h e schesiatic drawing o f t h e waves i s shown on f i g l b ( l a g r a n g i a n v e l o c i t i e s )

II

-

EAPERIIMENTAL SET-tiP

11.7

-

The p r o j e c t i l e l a u n c h e r

The p r o j e c t i l e i s launched b y an e x p l o s i v e d e v i c e shown on f i g u r e 2 h e x o l i l a 1151 s l o o l 1151 bulfer l h i PMMAlPOl o r o i s c l i l s 18.1 a i r 1x1

P.W.

-d

l a r g s l l a , and e,l

s h o r l i n e p i n s on ji 5 0 c i r c l e

F i g u r e 2

The d i s t a n c e X and t h e d i f f e r e n t t h i c k n e s s e s used i n o u r experinients a r e g i v e n i n Tabie 1 ( X has been chosen t a g e t a p l a t e a u on t h e V p ( t ) curve.

I l i

Copper 1 20 1 o,78

j

1,52

1 -1

Table 1 11.2

-

The t a r g e t

As shown on f i g u r e 2, each s t e p o f t h e t a r g e t

-

deplateci UVo,2 uraniurn a i l o y

-,

i s p a r t i a i l y covered w i t h a t r a n s p a r e n t n a t e r i a l ( w a t e r ) useci as winboh i n o r a e r t o r e c o r a t n e i i i o t i o n o f t h e i n t e r f a c e uranium-water t i u r i n g t h e shot.

F o r an experirnent, t h e b e s t window j s t h e one h a v i n g t h e sane shock isipeciance as t h e t a r g e t . ù n f o r t u n a t e l y , i n o u r case, w a t e r i s f a r f r o g t h i s c o n d i t i o n . Sut we chose i t m o s t l y t o a v o i d s p a l l i n g i n t n e t a r g e t , anci because i t s v a r i a t i o n o f r e f r a c t i v e i n t i e x versus p r e s s u r ? i s Icnown f r o n H.C. P u j o l s ' d a t a [ 3 ] . I n t h e p r e s s ü r e range o f Our experiments, t n e c o r r e c t i o n t o i n t r o u a c e f o r u ( n a t e r i a l v e l o c i t y o f t h e i n t e r f a c e ) i s

=

0 3 5 gi

ur i s t h e r e 3 1 v e l o c i t y , ui . t h e v e l o c i t y deUvced f r o z t h e i n t e r f e r o n e t r i c r e c o r d , i a s s u ~ i i n g vacuün i n s t e a d û f t r a n s p a r e n t window)

(4)

III - THE MEASUREMENT METMDS - 111.1

-

Chronometric p i n s

Two s h o r t i n g p i n s ( w i t h caps) i n c o n t a c t w i t h t h e f r o n t - f a c e o f t h e p r o j e c t i l e ( a t r e s t ) g i v e t h e b e g i n n i n g o f i t s m o t i o n .

Four o t h e r s h o r t i n g p i n s - t w o groups o f two f o r each t n i c k n e s s o f t h e t a r g e t - g i v e t h e t r a n s i t t i m e o f t h e shock wave i n t h e two p a r t s o f t h e t a r g e t .

The s i g n a l s d e l i v e r e d by t h e s e p i n s a r e r e c o r d e d on an e l e c t r o n i c d i g i t a l chronometer ( p r e c i s i o n +- 1 n s ) . ( s i x p i n s p e r s h o t ) .

111.2 - The P e r o t F a b r y v e l o c i r n e t e r T h i s apparatus has been d e s c r i b e d i n [4].

F i g u r e 3 shows t h e rough r e c o r d o f sfiot n o 2. Tne f o c a l l e n g t h o f t r i e l e n s l o c a t e d between t h e P.F. and t h e camera was 1000 mni, t h e d i s t a n c e between t h e p l a t e s o f t h e P.F. was 50 mm, t h e t i m e between markers 400 ns. The accuracy o f t h e measurement i s ' 7 m/s and? 10 ns.

I V - THE RESULTS --

I V . l - Shock v e l o c i t y i n t h e t a r g e t F i g u r e 3 I t i s o b t a i n e d by t h r e e ways :

a) t i i e s h o r t i n g p i n s l o c a t e d i n f r o n t - and on t h e b a c k - f a c e o f t n e t a r g e t g i ~ e t h e t r a n s i t t i m e f o r t h e t h i c k n e s s e s el and e

b ) t h e P e r o t Fabry v e l o c i m e t e r

-

g i v e s on th$ same record, t h e b e g i n n i n g o f t h e rno- t i o n o f t h e i n t e r f a c e t a r g e t - w a t e r f o r each t h i c k n e s s e and e

.

The t i m e d e l a y between t h e s e two v a l u e s i s t h e t r a n s i t t i m e f o r t h e h o c k &ve t o t r a v e l t h e d i s t a n c e ( e 2

-

el).

C ) Knowing t h e shock p o l a r s o f t h e t a r g e t and water, t h e measurement o f ~ h e i n t e r f a c e t a r g e t - w a t e r v e l o c i t y g i v e s a l 1 t h e c h a r a c t e r i s t i c values o f t h e shock i n t h e t a r g e t .

I V .2

-

The t a r g e t - w a t e r i n t e r f a c e v e l o c i t y v s t i m e .

The schematic diagram o f t h e waves i n Our experiments i s presented on f i g u r e 4.

The r e s u l t s o b t a i n e d - v e l o c i t y versus t i m e o f t h e i n t e r f a c e t a r g e t - w a t e r i n t h e experiments a r e shown on f i g u r e 5. The a r r i v a 1 t i m e s o f waves on t h e i n t e r f a c e a r e shown by arrows.

V - DATk ANALYSIS

V . l

-

E l a s t i c p r e c u r s o r

Ttie r e c o r d e d curves show t h a t t h e snock i n t h e t a r g e t i s preceded by an e l a s t i c p r e c u r s o r . Assu~ning t h a t UVo,2 a l l o y has a l i n e a r e l a s t i c b e h a v i o u r and obeys t o t h e Von Mises c r i t e r i o n , orle o b t a i n s 3,45 km/s f o r t h e e l a s t i c wave v e l o c i t y , 1,15 GPa f o r t h e h u g o n i o t e l a s t i c l i m i t , a m a t e r i a l v e l o c i x y o f 18 m/s, a compression r a t i o e ( = 1

-

V/Vo) o f 0.0052, a P o i s s o n ' s r a t i o v o f 0,19 and a y i e l d s t r e s s o f 0,851 GPa.

(5)

JOURNAL DE PHYSIQUE

shock o r ++

F i g u r e 4

4.a

-

Diagram t ( x )

-

4 . b V e l o c i t y vs t i m e o f t h e t a r g e t - w a t e r i n t e r f a c e

1 , , , , , , , , , ,

.5

l i m e Ii s

F i g u r e 5

Diagrams V i t ) f o r t h e experiments 1 and 2

(6)

V.2

-

Quasi e l a s t i c r e l e a s e waves

From t h e records, t h e v e l o c i t i e s o f t h e quasi e l a s t i c and p l a s t i c waves vs p r e s s u r e are shown on f i q . 6. The dashed curve i s o b t a i n e d w i t h t h e assump- t i o n t h a t , i n t h e pressure-materi a l v e l o c i t y d i agram, t h e i s e n t r o p i c r e l e a s e curves a r e mirror-images o f t h e h u g o n i o t c u r v e . So, one o b t a i n s f o r t h e p l a s t i c wave q u a s i - e l a s t i c wave v e l o c i t y :

. _ s

,,,.... .F".

_....'. .... -

. .. T ,fi,

- -

, - + - ' ~ - p l a s t i c wave -

/

, / u s i n g t h e l i n e a r r e l a t i o n U=A+Bu between

t h e shock v e l o c i t y fU) and t h e m a t e r i a l v e l o c i t y ( u ) along t h e hugoniot. F o r UVo,2, t h e c o e f f i c i e n t s used f o r t h i s r e l a t i o n a r e A = 2,445 km/s. B = 1,665 w i t h

F i g u r e 6

From t h e r a t i o between l o n g i t u d i n a l cL and p l a s t i c cs waves, ( c L / s s = k ) ,

2 2

WC g e t t h e Poisson c o e f f i c i e n t u ( 0 = 3-k /3+k )

.

The Poisson r a t i o v a l u e so o b t a i n e d i s 0,40 f o r t h e maximum s t r e s s o f 20GPa, and 0,43 f o r 29GPa.

Using t h e r e l a t i o n s between v e l o c i t y and s t r e s s jumps [5] , t h e c h a r a c t e r i s - t i c s of t h e quasi e l a s t i c waves a r e : v e l o c i t y 3,s km/s (4,2 km/s), p r e s s u r e jump 3GPa (3,7GPa) f o r a maximum shock pressure o f 2OGPa (29GPa).

We w i s h t o express Our thanks t o C. Segard and R. Audebal f o r p r e p a r i n g and making t h e experiments.

V I 1

-

REFERENCES

1 R.G. Mc Queen, J.W. Hopson, J.N. F r i t z RS1.53.2.245 (1982)

-

J.M.Brown

-

J.W. Shaner Proc APS Shock waves i n condensed m a t t e r Santa Fe 1983 - R.G. Mc Queen, J.N. F r i t z and C.E. M o r r i s Proc APS Shock waves i n conden- sed rnatter Santa Fe (1983).

2 C.E. M o r r i s , J.N. F r i t z , B.L. H o l i a n

-

Shock waves i n condensed m a t t e r 1981 AIP Conf

.

3 H.C. P u j o l s P r i v a t e communication.

4 M. Durand, P. Laharrague, P. L a l l e , A. Le Bihan, J . Morvan, H.C. P u j o l s RSI 48.3.275 (1977)

5 J.R. Asay, L.C. Chhabildas, D.P. Dandekar JAP 51.9.4774 (1980)

Références

Documents relatifs

To test whether the vesicular pool of Atat1 promotes the acetyl- ation of -tubulin in MTs, we isolated subcellular fractions from newborn mouse cortices and then assessed

Néanmoins, la dualité des acides (Lewis et Bronsted) est un système dispendieux, dont le recyclage est une opération complexe et par conséquent difficilement applicable à

Cette mutation familiale du gène MME est une substitution d’une base guanine par une base adenine sur le chromosome 3q25.2, ce qui induit un remplacement d’un acide aminé cystéine

En ouvrant cette page avec Netscape composer, vous verrez que le cadre prévu pour accueillir le panoramique a une taille déterminée, choisie par les concepteurs des hyperpaysages

Chaque séance durera deux heures, mais dans la seconde, seule la première heure sera consacrée à l'expérimentation décrite ici ; durant la seconde, les élèves travailleront sur

A time-varying respiratory elastance model is developed with a negative elastic component (E demand ), to describe the driving pressure generated during a patient initiated

The aim of this study was to assess, in three experimental fields representative of the various topoclimatological zones of Luxembourg, the impact of timing of fungicide

Attention to a relation ontology [...] refocuses security discourses to better reflect and appreciate three forms of interconnection that are not sufficiently attended to