unclassified ad number limitation changesthe 1100-0 and 7075~t6 alumnu. alloys and the borosilicate...
TRANSCRIPT
UNCLASSIFIED
AD NUMBER
LIMITATION CHANGESTO:
FROM:
AUTHORITY
THIS PAGE IS UNCLASSIFIED
AD875390
Approved for public release; distribution isunlimited. Document partially illegible.
Distribution authorized to U.S. Gov't. agenciesand their contractors; Critical Technology; SEP1970. Other requests shall be referred to AirForce Materiels Laboratory, MAMN, Wright-Patterson AFB, OH 45433. This document containsexport-controlled technical data.
afml ltr, 9 mar 1973
§ .
CO
00
^
DEVELOPMENT OF A NONDESTRUCTIVE TESTING
TECHNIQUE TO DETERMINE FLAW CRITICALITY
September 1970
<j>
P. P. Crimmins
Contract F33615-68-C-1705
Sponsored by
Advanced Research Projects Agency AR PA Order No. 1244
Prooram Code Number 8D10
3 OCT 14 1370
tf
This document is subject to special export controls and each transmlttal to foreign governments or foreign nationals may be made only with prior approval of the Manufacturing Technology Division. ^'/tf/T/Zp/iys??/?/?? AS"
4
«•PO|«t »olid propulsion company f. C. BOX 13400 SACRAMENTO, CALIFORNIA 9SB13 • A DIVISION OF AEROJET-CENERAL ©
^ Ö
. .
When Government drawings, specifications, or other data are used for
any purpose other than a definitely related Government procurement operation,
the Government thereby incurs no responsibility nor any obligation whatsoever,
and the fact that the Government may have formulated, furnisheri, or in any vay
supplied the said drawings, specifications, or other data, ia not be regarded,
by implication or otherwise, as in any manner licensing the holder or any
other person or corporation, or conveying any rights or permission to manu-
facture, use, or sell any patented invention that may in any way be related
thereto.
Qualified users may obtain copies of this report from the Defense
Documentation center.
FORSWABD
This report wad prepared by P. P. CrJnmlns of the Advanced Technology
Operations, Metallurgy and Materials Integrity Department, Aerojet Solid
Propulsion Company, Sacramento, California. The research was supported by the
Advanced Research Projects Agency of the Department of Defense and was monitored
by the Air Force Materials Laboratory, MAMN, undev Contract F33615-68-C-1705.
This report covers the period 1 June 1970 through 31 August 1970.
Effective Date of Contract: 1 July 1968
Expiiw-ation Date of Contract: 30 June 1971
Amount of Contract: $208,123
Principal Investigator: C. E. Hartbower
Telephone: (916) 355-6509
mem I ..
TABLE CF CONTENTS
Abstract
I Introduction
II Overall Program Scope
III Technical D cusaion of Work Performed
Page
i
3
5
TABLE LIST
I Test Materials and Conditions
II SWAT-Continuous Recording of Delayed Cracking HY-130
Horizontal Weldment 1 x 18 x 36-in.
6
7
FIGURE LIST
4
5
6
7
8
Relationship Between Stress Intensity Factor and Cumulative
Stress Wave Couni - 18% Nickel tiaraging Steel in Distilled
Water - Sustained Load
Total Stress Wave Emission versus Applied Stress Intensity
Factor - D6AC Steel Tempered at 600oF or 1100°? - 0.29-in.
thick, numbers refer to specimen identity. Rising Load to
Failure
Tr-tal Stress Wave Emission versus Applied Stress Intensity
Factor - D6AC Tempered at llOO'F - 0.10 in. - Numbers refer
to specimen identity. Rising Load to Failure
Unflawed Tensile Specimen for Structural Metals
Typical Part-Through Crack Tensile Specimen for Structural Metals
Single-Edge Notch Specimen for Structural Metals and Crack
Opening Displacement Gage
Standard Sheet-Type-Fatigue Tensile Specimen
SWAT-Continuous Recording of Delayed Cracking HY-130 Horizontal
Weldment 1 x 18 x 36-in.
10
11
12
13
14
15
ii
■ ■■■» m
ABSTRACT
V A brief deacriptlon is presented of the program scope for additional
studies to develop a nondestructive testing technique to determine flaw
criticality. The results of limited instrumentation evaluations for obtaining
real time stress wave emission data are discussed. The fabrication of speci-
mens to be tested at Aerojet and during concurrent programs under ARPA
sponsorship at the University of Michigan and North American Rockwell Corporation
•y is also discussed.
1
ili
■■•- ' :«.«•
I. INTRODUCTION
Thl, pro,r« 1, being co„duct.d to dev.lop oondMtructl« t..tlng
crlterl, rtlch c™ b. .^ioyed to dot.ct a„d loc.t. n... 1„ .ttucturo. .„d ...oo, tbeir potootiol for „aohlog . crltlcl f.Uur. condition, ^o b..lc
tochnoxoglo.. stro,. W.vo tou.ion „d fr.ot.r. „ochonlc, ore bolng .mploy.d to «ccompllol, thl« objoctlvo.
Str.„-„.ve ^..^ „. gener>ted by ^^^^ |Mteriaia ^ ^ ^^^
tho rele«. of kinetic energy fro. e defomntlon mechenls.. The region
.urroundlng tbi. dofo^tlo» .11! .cq„lre. If o„ly te^orerlly. . no. end
«r. eteblc .tree. fleW. Thle n... l^„l.ively d.velopad> „„., fuu ^
give rise to oeclUetlons ^Ich decoy duo to the Inoleetlc bobevlor of the
..terlel. The oleetlc .eve. prop.gete out fro» the .ource end ere detoctod
os «U dleplece^nt. on tho ourfec. of tho .p.cl.en. Ihe.e dlepUc^nt,
otrooe-weve »leelone, con be need to ioc.to tho source of the e.l„lon end provide a aeon, „f M.c..lng the iacnmM of defomatlon ^^ ^ ^^^
I-lneer ele.tlc fracture machanlc. 1. an onglnoarlng „ethod of detemlnlng
the streeee. In the vicinity of e .tree, conc.ntr.tlon. Ihoe. .dutlon, ,r.
d.v.loped through eppUcetlon of oleetldty theory end they detomlne linear
rel.tlon.hlp. between .tr... function, „d dl.^.lon.1 function, of the flew
Thl. .trea,-lnten.lty fector" which depend, on the fUw'a .1M, 8hape and
orlantetlon with re.pect to loed end/or .peclMn goo^try. 1. a «een. of defining
the rat. of euppiy of .„Uebio energy for creek propegatlon In term, of the
•PPlIod atre,. (Uld within tho .peclaen. The advantage of ualng the atro.a-
ntonelty factor (K) 1, th.t It My be eveiuefd In MlM of the appUed atre...
the crack ,1« a„d tho .pectaen dlM„.lon. and 1. thu. reduced to a .trees
enaly,!. probl... Through thl. engineering „ethod, any probl«, .olvbl. by llne.r .tree. an.ly.l. l. c.?.bu ot „.^ .n.ly2eJ ^ , t
point of view.
Page 1
-'-..«M.
Durini th« previous ycarf studl». undar thli contr«ct(Raf'^ it was
d«i«aiiitratad that tha itraas wava data may be paramenrically related to stress-
Intenoity factors. These relationships ate being further investigated during
the present etudy for a variety of materials and use conditions. This report
covarr Che progress during the period of June through August 1970.
Ref.: Green, A. T. and Martbower, C. E., Development of a Nondestructive Testing Technique to Determine Pi»- Critlcallty, May 1970, Interim Report under Contract P336I5-<8-C-1 05.
Page 2
■
H. OVERALL PROGRAM srm>f
The progr^n. to b. performed to develop the Stress-Weve-Emission fech-
nology for a nondestructive Inspection systen. Is divided into three phases-
a brief description of the work planned in each is shown below.
PHASE I - SPECIMEN FABRICATION
During Phase I. the species for testing in subsequent progran. phases
will be fabricated. The 1100-0 and 7075~T6 aluMnu. alloys and the Borosilicate
Glass and Borsic reinforced alumina. ..trix composite materials will also be
procured during this phase. The D6aC steel and 6A1-4V titanium materials are
presently available from the first year's study under Contract F33615-68-C-1705
the results of which were published in Reference (1). The materials and
appropriate thicknesses and conditions to be tested during the program at Aerole^ are shown in Table I.
In addition to the tensile, single-edge-notch tensile and part-through-
crack tensile specimens to be tested at Aerojet, standard sheet type fatigue
specimens will be fabricated and delivered to the University of Michigan and
North American Rockwell Corporation for their programs.
PHASE II - SPECIMEN TESTING AND DATA ANALYSIS
During Phase II. specimen testing will be performed and will be accompanied
by continuous data analysis throughout Phase II. Primary emphasis will be to
develop relationships between incremental fracture and failure, and significant
stress wave emission characteristic, whlct en be employe, to locate and assess
flaw crlticallty in structures for a v.ru..y of materials and use conditions.
Stress wave characteristic, which will b. inv.tlg.t.d include amplitude
cumulative count and rat. of occurranc. Th... ch.r.ct.ristic. will be related
to fractur. b.h.vlor through fracture machanlc.. It 1. expected that further
Page 3
^PpM«*Hl'Mamil.K WtWW* fc-. l W»! I
refinement in such relationships as developcu during the first year's program
and shown in Figures 1 through 3 will be made. Other stress wave emission
characteristics which will be studied Include wave shape and frequency content.
Concurrently, stress wave emission attenuation, discrimination in high
noise backgrounds, and source trlangulation techniques will also be evaluated.
PHASE III - SUIMARY TECHNICAL REPORT
The Summary Technical Rf u.. including results from this and the first
year's program will be prepared during Phase III.
Page 4
II1- TECHNICAL DISCUSSION OF WORK PERFORMED
PHASE I - SPECIMEN FABRICATION
The D6aC steel and 6A1-4V titanium sheet and plate materials were
available from the first year's program while the 7075-76 aluminum, borosilic^te
glass and the Borsic reinforced aluminum matrix composite materials were procured
for this program. Fabrication of the tensile (Figure 4), single-edge-notch
tensile (Figure 5) and part-through-crack tensile (Figure 6) specimens has been
initiated and is proceeding. The borosilicate glass and composite materials have
been ordered, but not received.
During the reporting period, the standard, sheet-type fatigue specimens
(Figure 7) required foi programs at the University of Michigan and North American
Rockwell Corporation were also fabricated and delivered.
PHASE II - SPECIMEN TESTING AND DATA ANALYSIS
So tests were performed during this period using test materials specifically
procured for the program. However, instrumentation evaluations were continued
where possible during tests conducted as part of other studies.
The most significant of these evaluations are those being conducted to
evaluate instrumentation systems which will provide a continuous, long-term moni-
toring capability with SWE data output which can be employed to relate the stress
wave data to applied stress Intensity and incremental crack area. As indicated
in Figures 1 through 3, cumula'-lve stress wave emission count appears a signifi-
cant parameter for this purpose. During the reporting period, a SWE monitoring
system has been assembled which will meet this requirement. The system has been
employed to monitor delayed cracking in weldments. Typical data obtained from
these tests which illustrates the discontinuous nature of the cracking, is shown
In Table 2 and Figure 8. Additional evaluations of this system and other Instru-
mentation components will be performed when the specimens for thii program arc
available for testlag.
Page 5
Material
D6aC Steel
(0.1 and 0.3-in.
thick)
TABLE I
TEST MATEFIALS AND CONDITIONS
Modulus
30 x 10
Approximate Ultimate Streugth (ksl)
220
280
Borslc Reinforced Aluminum
Compos it a
(0,1-in. thick)
32 x 10 1A0
Ti-6A1-4V
(0.1 and 0.25-ln.
thick)
16 x 10 140
17'
7075-16 Aluminum
(0.09 and 0.25-in.
thick)
10.A x 10l 85
Borosilicate Glass 9.5 x 10
Page '.
. - My i
I
< i
>2
w 3 pq
3
UJ O ^H
u. h- O Z
UJ
Q UJ a: ^ o o _l UJ < cm 1—
2: (Si O ZD M o — =3 Of ^ O —. zc t— 2; o O ro
i—i o i
h- >
< *
^ CO
TTTTTTT TT-l—1—ill]
S SRC " ! 1 | ; ! ! !
i ;s « ; ltt|s!
1 I ! I :i 1
MM 1 ! l
1 i i 1 %■ A
|<| - s « |
H a ■ a _ M 1 , ! M i a
i
i r 1 i
| | 1
; 1 1 1
H T ■ |i|- i ---"i« a «B K Si s «
I—' i '—'—l—
si«' eels -'5
—i—
i tlii
a = g = aa-a Mt» S -s a- s-
IcSSSSii isS S g§ £« ||| « !
K
1 1 Is
1
3 a 3 5 »
«i M i
S
i
♦ | — 1_ _ ^
»'fjilSji il S A
■ IS
jlli fr-"
IS
i
g «is«
si 1
3 K 1
£
1 1
S
i
B 5
1 S
3
i
a
i
ilaii eje
i 1 1
il r e e ir i
Page 7
200 210 220 230
STRESS INTENSITY (KSI-IN.1/?)
210
Figure 1. Relationship Between Stress Intensity Factor and Cumulative Stress Wave Count - 18% Nickel Maraglng Ste-t In Distilled Water * Sustained Load.
Page 8
.
200
180 -
160 -
^ f-- 1411 X K :z 13 P U 120
8 ?» oo
3 100 111 > < 3: u^ u> UJ 80 \- <st
U h- < 6Ü -1 ^ —( U
40 -
20 -
r ,^ 40 200
1 80 120 160 200 240
APPLIED STRESS INTENSITY (KSI - IN/2)
Figure 2. Total Stress Wave Emission versus Applied Stress Intensity Factor - D6AC Steel Tempered at 600oF or 1100CF - 0.29-ln. thick, numbers refer to specimen Identity. Rising Load to Failure.
Page 9
APPLIED STRESS INTENSITY (KSI - IN/7)
Figure 3. Total Stress Wave Emission versus Apulied Stress Intensity Factor - D6AC Tempered at llOO^F - 0.10 in. - Numbers refer to specimen identity. Rising Load to Failure.
Page 10
. I
iilniwai-nr—
10.00
5 R. (TYP)
1.00
1.015 i:o88DIA (TYP)
SPECIMEN IDENTIFICATION (2 PLACES)
Figure 4. Unflawed Tensile Specimen for Structural Metals
Page 11
1.250!;^ DIA (TYP)
-H U- THK
.50 R. (TYP)
PART-THROUGH.CRACK
SPECIMEN IDENTY (2 PLACES)
Figure 5. Typical Part-Through Crack Tensile Specimen for Structural Metals
Page 12
mm ^-^gy-TTWt..»;?»»'»"''—>■"" ] • mrmfmm mmmmmmm^j
*-1.500 ±.002
12.00
i.oo !:ggi DIA
(2 HOLES)
-^ ^»-THK
NO. 10-32
,.-LI:]J
•2o0 oL
ij^-l.
VIEW A
Figure 6. Single-Edge Notch Specimen for Structural Metals and Crack Opening Displacement Gage
Page 13
n
^ R
0
S!
to OJ
ai
8 -i
8 ai LU (*■
_J a. a:
O
Of < UJ
'1 ID 03
o 5
z _J tu (0
2 to Di H a y in C£ to
U Bl VO
-i
3 UJ
5 i- <
UJ
>
i
<] " <^
c
I u a
C/3
u c 0) H
n
ai a s I
4J <U 0)
m
a)
§ in
ai
60
Page 14
| * .■ -^^»Pw» ,----- ■• ' i;
X
o o z o to
p
Ftgure 8. SWAT-Contlnuoui Recording of Delayed Cracking Hy-130 Horizontal Weldment 1 x 18 x 3b-ln.
m
50
4a.
»-
f to-
il-
I6--
14-
12-
10 -
4-
2-
oL 10
ir e ■» •
^
s ■a CM
</> 1/1
O O X X
t/l to >- > < < o o
J 1 I I I INI 20 40 80
J I I I I I IN I | I | | I I 200 400 800 2000 4000 8000
TIME (MINUTES) LOG SCAI£ (STARTING 228 MINUTES AFTER FINISHING LAST WELD PASS)
r£ae 15