A Ductile Tear Fracture Analysis of Lap Welded Joints
Numerical analysis of the ductile fracture of lap welded joints has been performed for a standard CT specimen. Mono-, bi- and trimetallic CT configurations were studied in order to compare the J-integral and CTOD global approaches with a local approach (Rice and Tracey model). It is found that...
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| Дата: | 2004 |
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Інститут проблем міцності ім. Г.С. Писаренко НАН України
2004
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| Цитувати: | A Ductile Tear Fracture Analysis of Lap Welded Joints / A. Imad, M. Nait Abdelaziz, G. Mesmacque // Проблемы прочности. — 2004. — № 4. — С. 68-79. — Бібліогр.: 19 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1859617451731320832 |
|---|---|
| author | Imad, A. Nait Abdelaziz, М. Mesmacque, G. |
| author_facet | Imad, A. Nait Abdelaziz, М. Mesmacque, G. |
| citation_txt | A Ductile Tear Fracture Analysis of Lap Welded Joints / A. Imad, M. Nait Abdelaziz, G. Mesmacque // Проблемы прочности. — 2004. — № 4. — С. 68-79. — Бібліогр.: 19 назв. — англ. |
| collection | DSpace DC |
| container_title | Проблемы прочности |
| description | Numerical analysis of the ductile fracture of
lap welded joints has been performed for a standard
CT specimen. Mono-, bi- and trimetallic
CT configurations were studied in order to compare
the J-integral and CTOD global approaches
with a local approach (Rice and
Tracey model). It is found that the above
change in configuration has no impact on evolution
of the global parameters, while the void
growth ratio R/R is very sensitive to the
stress and strain fields around the crack tip. Furthermore,
using the parameter R/Ro distribution
at the crack tip, allowed us to predict the
crack propagation direction in the case of lap
welded joints.
Выполнен численный расчет параметров вязкого разрушения компактных образцов, моделирующих
сварное соединение внахлестку. Исследовались моно-, би- и триметаллические
конфигурации компактных образцов с целью сравнения глобальных (J-интеграл и раскрытие
вершины трещины) и локального (модель Райса-Трейси) подходов. Показано, что такие
изменения конфигурации образцов не влияют на глобальные параметры, в то время как
локальный параметр - коэффициент роста пор R/R0 - весьма чувствителен к изменению
полей напряжений и деформаций в окрестности вершины трещины. Предлагается направление
распространения трещины в случае сварного соединения внахлестку прогнозировать
по распределению параметра R/R0 в окрестности вершины трещины.
Виконано числовий розрахунок параметрів в’язкого руйнування компактних зразків, що моделюють зварне з ’єднання внапуск. Досліджували моно-, бі- та триметалічні конфігурації компактних зразків із метою порівняння глобальних (J-інтеграл та розкриття вістря тріщини) і локального (модель Райса-Трейсі) підходів. Показано, що такі зміни конфігурації зразків не впливають на глобальні параметри, в той час як локальний параметр - коефіцієнт росту пор R/R0 - дуже чутливий до зміни полів напружень і деформацій в околі вістря тріщини. Пропонується напрямок поширення тріщини у випадку зварного з ’єднання внапуск прогнозувати по розподілу параметра R/R0 в околі вістря тріщини.
|
| first_indexed | 2025-11-28T23:07:02Z |
| format | Article |
| fulltext |
UDC 539.4
A. Im ad,a M. Nait Abdelaziz,b and G. M esm acqueb
a Laboratoire d’Etudes des Structures, Ecole HEI, Lille, France
b Laboratoire de Mécanique de Lille, Lille, France
УДК 539.4
Анализ вязкого сдвига в сварных соединениях внахлестку
А. И мад^ М. Н аит Абделазиз6, Г. М есмакю 6
а Лаборатория исследований структуры, Лилль, Франция
6 Лаборатория механики, Лилль, Франция
Выполнен численный расчет параметров вязкого разрушения компактных образцов, модели
рующ их сварное соединение внахлестку. Исследовались моно-, би- и триметаллические
конфигурации компактных образцов с целью сравнения глобальных (J-интеграл и раскрытие
вершины трещины) и локального (модель Райса-Трейси) подходов. Показано, что такие
изменения конфигурации образцов не влияют на глобальные параметры, в то время как
локальный параметр - коэффициент рост а пор R/R0 - весьма чувствителен к изменению
полей напряжений и деформаций в окрестности вершины трещины. Предлагается направ
ление распространения трещины в случае сварного соединения внахлестку прогнозировать
по распределению параметра R/R0 в окрестности вершины трещины.
Ключевые слова : вязкий сдвиг, сварные соединения внахлестку, J -интеграл,
коэффициент роста пор.
Introduction. Fracture criteria based upon the global approaches are
commonly applied to the ductile tearing of welded joints. For instance, the energy
rate interpretation of the J-integral [1] allows one to assess the fracture toughness
(given in terms of a critical value of this parameter) for such components.
Numerous data on the influence of mismatching on fracture parameters such as
J-integral, crack tip opening displacement (CTOD), or Charpy V-energy results
are available in the literature [2-12].
As to the failure of components with mismatched strength values, most
studies to be found in the literature deal with standard notched specimens (CT,
SENB, SENT, etc.) exhibiting a central zone of weld metal (WM) surrounded by
two adjacent zones of base metal (BM). Such specimens exhibit the fracture
toughness values which do not characterize the central zone in an intrinsic
manner. In fact, it is an apparent toughness which depends mainly on several
parameters such as [2-5]:
- mismatch ratio;
- hardening exponents of each material (BM, WM, and HAZ);
- fracture resistance of each material;
A Ductile Tear Fracture Analysis of Lap Welded Joints
© A. IMAD, M. NAIT ABDELAZIZ, G. MESMACQUE, 2004
68 ISSN 0556-171X. Проблемы прочности, 2004, № 4
A Ductile Tear Fracture Analysis
- size and position of the initial notch;
- length of the central zone;
- joint configuration, etc.
The mechanical heterogeneity of a welded structure (BM, WM, and HAZ)
added to the heterogeneity of the microstructure (coarse-grain and fine-grain
HAZ) make fracture study of such components so complicated, that a question
on the validity of a global approach arises.
As ductile tearing proceeds from mechanisms essentially described by the
void growth phase at the crack tip, local approaches can be applied as alternative
and complementary research tools. Many theoretical models have been developed
to predict the void growth rate, as well as numerical methods used for their
refinement and numerical application [14-19].
In this work, a FEM analysis has been performed in order to compare these
two different approaches namely the /-integral and CTOD parameters with the
void growth rate parameter R /R 0 from the Rice and Tracey analysis [15].
Using a CT specimen, three different configurations (Fig. 1) have been
analyzed:
(i) monometallic (BM), where only the BM is considered;
(ii) bimetallic (BM+WM), where the HAZ is neglected;
(iii) trimetallic (BM+HAZ+WM), where the complete joint is considered.
Monometallic Bimetallic Trimetallic
Fig. 1. Three configurations of the CT25 specimen (schematic).
For each configuration, the J and CTOD parameters, as well as the parameter
R /R o , are numerically determined. For the base metal, for which experimental
data of ductile tearing are available, the crack growth is modeled using the Rice
and Tracey model. Numerical results are then compared to experimental data.
1. M aterials. The weld metal and the base metal are respectively 316L and
a Z3CN20-09M stainless steels. Their chemical composition is given in Table 1.
The mechanical behavior of each component (BM, WM, and HAZ) is
described using the power law:
o = o Y + k£ np , (1)
where £ p is the plastic strain, o y is the yield stress, while n and k are the
material constants.
The experimental values of o 0 2 , n, and k obtained from experimental
tensile tests performed at 673 K [17-18] are presented in Table 2. The elastic
constants E and v are respectively 176-10 MPa and 0.3.
ISSN 0556-171X. npoôëeMbi npounocmu, 2004, N 4 69
A. Imad, M. Nait Abdelaziz, G. Mesmacque
T a b l e 1
Chemical Composition of Stainless Steels (%wt.)
Material C S P Si Mn Ni Cr Mo Cu N O
Base metal 0.015 0.003 0.022 1.15 1.01 9.74 20.01 0.39 0.125 0.081 0.006
Weld metal 0.008 0.011 0.018 0.51 1.19 12.70 19.20 2.60 0.137 0.051 0.007
T a b l e 2
Values of the Yield Stress and the Parameters of the Power Law
Characteristic BM HAZ WM
к, MPa 1066.9 324.58 324.58
n 0.826 0.206 0.206
а 0 2, MPa 133 320 412
2. Num erical Study. The modeled specimen is a standard CT specimen of
25 mm thickness, 50 mm width and with ratio a/W = 0.63. The Systus FEM
software has been used in this investigation. Large strains, plane strain situation,
and isotropic hardening with a von Mises rule have been assumed in the
calculations. The FEM modeling incorporates the eight-noded isoparametric
element (six nodes for triangles) [14, 17-19].
As shown in Fig. 2, the meshing consists of a fine square mesh around the
crack tip (0.2 X 0.2 mm) and a relatively coarse mesh near the boundary. Because
of symmetry, only half of the specimen was modeled, in the case of monometallic
configuration. The typical discretization consisted of 1954 nodal points and 618
elements. Concerning the case of the heterogeneous material (bi- and trimetallic
configurations), the whole specimen has to be analyzed. This meshing contains
1236 elements and 3857 nodes.
The crack is located in the HAZ, about 1 mm from the melting line (the
width of the HAZ is taken equal to 3 mm), while it was assigned at the interface
for the bimetallic specimen. The specimen loading is applied, step by step, in
terms of assigned displacement.
Fig. 2. FEM meshing of the CT specimen.
70 ISSN 0556-171X. Проблемы прочности, 2004, № 4
A Ductile Tear Fracture Analysis
3. Results and Discussions. Firstly we have obtained FEM results on global
parameters (the applied load, ./-integral, and CTOD) and the local parameter
R/R 0 and then studied their evolution as function of the load line displacement.
In a second step, a FEM analysis of crack growth for the base metal, based
upon a critical growth rate criterion has been performed and results were
compared to the experimental data in terms of J — Aa evolution.
3.1. Load-Displacement. For all the configurations, the evolution of the load
per unit thickness as a function of the assigned displacement is shown in Fig. 3.
--o ---B M e xp .
— ■ —BM num.
— a — bimetallic
X HAZ
— — WM num.
— • — WM exp.
0 0.5 1 1.5 2 2.5
Displacement d (mm)
Fig. 3. Load as a function of the assigned displacement.
In the case of the base metal specimen, for which experimental results are
available a good agreement is pointed out between experimental and numerical
data, indicating that the hypothesis of computation are reasonable.
When comparing the bi- and trimetallic configurations, similar behavior is
observed. For example, for a given displacement (d = 2 mm), the relative
difference between the corresponding loads does not exceed 5%.
The relative difference between the bimetallic or trimetallic curves and the
monometallic one is not high for BM (approximately 20% for d = 2 mm).
However, it is more significant when considering the WM curve (89% for the
same displacement). The global behavior of the bi- and trimetallic configurations
is assumed to be governed by the base metal because of its lower yield stress.
Indeed, these configurations exhibit a generalized yielding in the base metal while
the plastic zone in the WM is rather small. This observation is often shown in
overmatching case (in our case, the overmatching ratio is equal to M = 3.1).
3.2. Profile o f the Crack Opening. In the case of the monometallic and the
trimetallic specimen, Fig. 4 shows the crack lips opening versus the distance X to
the crack tip in a deformed state (here d = 2 mm).
One of the most evident features is the typical dissymmetry of the profile
when considering the trimetallic configuration. This is a consequence of the
plastic zones around the crack which is more critical in the base metal. Indeed, in
this case, the plasticity is confined in the HAZ at the beginning of the loading, but
it develops quickly from the interface towards the BM in which a full-scale
yielding process takes place because of its lower yield stress.
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A. Imad, M. Nait Abdelaziz, G. Mesmacque
T r im e ta l lic
C r a c k o p e n in g
0 .4 -
& -------- -------- «*i---- ..
BM
0 .2 -
\ ' 1 '
X(m m)
Crack
tip
-0 .7 -0 .6 -0 .5 -0 .4 -□ .3 -0 .2 -o ,ju -
-0 .1 -
-0 .2 -
Fig. 4. Profile of the crack opening (d = 2 mm).
No significant plastic strain is observed in the WM zone. Thus, the plastic
zone is mushroom-shaped, which is typical for lap welded joints.
In the case of the bimetallic specimen, the crack is located at the interface.
The yielding occurs and develops essentially in the BM.
Furthermore, concerning the trimetallic configuration, the total CTOD (d tot)
can be divided into two components: the first one related to the base metal (dBm )
and the second one related to the weld metal (dWM). As shown in Fig. 5, because
of the mismatching level, the first component contributes about 85% of the total
CTOD when the displacement is 2 mm.
Fig. 5. Stot, SmB , and 6WM versus the loading points displacement (trimetallic).
When plotting the total CTOD versus the displacement (Fig. 6), similar
behaviour for the three configurations is observed. As it was already mentioned,
the CTOD value is mostly governed by the base metal. This statement is in
agreement with the results obtained by Toyoda [5].
72 ISSN 0556-171X. npo6n.eMH npounocmu, 2004, N 4
A Ductile Tear Fracture Analysis
Fig. 6. CTOD vs displacement for the three configurations.
3.3. The J-Integral Analysis. The /-integral has been calculated following a
chosen path using the expression proposed by Rice [1]:
, , y ~ duW (£ )dx 2 - t —— ds
dx. (2)
On an other hand, using the load-displacement numerical data, the energy
parameter J has been determined via the ASTM procedure [16]:
U,
+
P B(W — a o)
where E = e / (1 — v 2); for the CT specimen
r\ p = 2 + 0.522(1— a 0 / W ),
(3)
(4)
where K 1 is stress intensity factor, a o is the initial crack length, W is the
specimen width, B is the specimen thickness, and Up is the plastic component
of the area under load-displacement curve.
It is noted that, for each configuration, a good agreement between the
J-integral and the energy parameter J has been obtained. Indeed, the maximum
difference between the results is less than 5%.
A plot of the J -integral versus the loading points displacement is presented in
Fig. 7. The results confirm our primary observations on the load-displacement
curves. Again, a similar global behavior is observed, indicating that this
parameter is not much affected by change in the specimen configuration.
Finally, for each configuration, a linear relationship between J and CTOD is
obtained as already observed in [7, 13].
ISSN 0556-171X. npoôëeMbi npounocmu, 2004, N9 4 73
A. Imad, M. Nait Abdelaziz, G. Mesmacque
140 | O monmetallic
120 - ° bimetalic
E - Atrimetallic
S 100 : r , . , , -,x BM {exp)
r 80
I 60 é
40—>
é
■20
0 i-
0 1 1.5
Displacement d (mm)
2 2.5
Fig. 7. /-integral versus displacement for the three configurations.
From the above-mentioned results either in terms of load-displacement,
CTOD or /-integral, one may conclude that the global behavior of the welded
joints in a lap joint situation, is mainly governed by the material which
mechanical properties the worst. This raises the question about the validity of a
global approach when dealing with a fracture of mismatched welded joints.
3.4. Void Growth Model. This kind of model is based upon the assumption
that ductile failure is the consequence of void growth mechanisms which initiate
from inclusions or particles contained in the material. Many models, giving the
evolution of the defect size, have been proposed, e.g., [14, 15]. More precisely,
Rice and Tracey [15] expressed the void growth rate as
where R 0 is the initial radius of the void, R is the current radius of the void, o m
is hydrostatic stress, o eq is the equivalent von Mises stress, and de eq is
increment of the equivalent plastic strain.
For a given element, the void growth parameter R /R 0 is computed, using
the average values of stresses and strains [14, 19]. Considering the trimetallic
specimen, the values of this parameter are calculated in the element lying to the
BM side since the BM exhibits the lowest yield stress [14, 17, 19]. Figure 8
shows the evolution of the void growth rate as function of the load line
displacement for the three configurations.
In contradiction with the /-integral, the void growth parameter is very
sensitive to the stress and strain distribution as confirmed by the significant
difference observed in the evolution of R /R 0 . As shown in Fig. 9, a plot of this
parameter as a function of J leads to a similar conclusion.
Considering these results, it must be emphasized that:
Because the crack is located at the interface, the bimetallic specimen exhibits
higher values of R /R 0 than those obtained for the other configurations. Because
the void growth parameter increases quickly, this case seems to be the most
d (ln R /R 0 ) = 0.283exp 1.5 m
(5)o eq
74 ISSN 0556-171X. npoôëeMU npoHHocmu, 2004, № 4
A Ductile Tear Fracture Analysis
harmful. This is mainly a consequence of the yielding process which develops in
the base metal only.
Figure 9 also illustrates the beneficial effects of the HAZ when considering
the trimetallic specimen. In this case, data on R /R 0 constitute a lower limit
because they are computed for the HAZ with the yield stress approximately twice
as high as that of the BM.
0 0.5 1 1.5 2 2.5
displacement (mm)
Fig. 8. R/R0 vs displacement for the three configurations.
Fig. 9. R/R0 vs J for three configurations.
Therefore, adopting the softer material properties to characterize fracture of
lap welded joints seems to be a conservative approach.
3.5. Crack Growth Modeling. The crack growth simulation is modeled using
a critical void growth rate (R/R 0 ) c criterion value which is determined by
combining experimental and FEM results in the BM case.
On one hand, according to experimental results of fracture test on a CT25
specimen, the critical load Pt , corresponding to the crack initiation, has been
determined. Precisely, Pt = 600 N/mm, which corresponds to the point where the
crack extension has reached 0.2 mm (Fig. 10).
On an other hand, the FEM analysis of the same specimen gives the
evolution of the void growth ratio, determined in the first element in front of the
crack tip, as a function of the applied load. According this curve, the (R /R 0 ) c
value corresponds to Pi value (see Fig. 11).
ISSN 0556-171X. npoôëeMbi npounocmu, 2004, N 4 75
A. Imad, M. Nait Abdelaziz, G. Mesmacque
1200
■g1 1000
E -a—
Z 800
■D
g 600
■D.2 400 r
Q. T
< 200 J
. . , , , , , . . . . . . .
31.5 32 32.5 33 33.5 34
crack length (mm)
Fig. 10. Applied load vs crack length (BM case): experimental determination of the critical load
value Pi.
2,5
0 E-----------'------------ '------------ '------------ '------------ '------------ '------------ '------------ '------------ '------------ '------------ '------------1------------
0 200 400 600
Applied load (N/mm)
Fig. 11. Void growth ratio vs applied load (numerical results for BM case): critical void growth
ratio determination.
For to enlarge the crack, the FEM analysis has been achieved using a node
release technique which assumes the crack propagation direction is known [14,
19]. In our case, where only the monometallic configuration is considered, we
assume that the crack propagates in the initial plane notch. The crack is increased
by an amount Aa = 0.2 mm (corresponding to the element size around the crack
tip) by releasing the nodes of the first element in front of the crack tip when
(R /R 0 ) c is reached in this element. Increasing the load, the same operation is
carried out again until reaching the crack propagation instability. Figure 12 shows
the different steps used in the node release technique.
For each crack extension, the energy parameter J is determined using the
ASTM procedure [13] briefly developed above. A comparison of experimental
and numerical results is given in Fig. 13, where J is plotted versus crack
extension Aa. Experimental and numerical estimation of the tearing rate dJ j da
are in good agreement but for a given numerical value of J is clearly
underestimated. This divergence may be the consequence of the following
factors:
1). The degree of uncertainty on the critical value of the void growth
parameter.
76 ISSN 0556-171X. npo6n.eMH npounocmu, 2004, N 4
A Ductile Tear Fracture Analysis
2). The element size of the meshing, which plays an important role in the
crack propagation simulation [19]. It seems that the values we have assigned here
are high enough for the constant J, and therefore, the crack extension Aa (which
is equal to the element length) is overestimated.
3). The fact that the FEM analysis has been performed with the assumption
that crack propagates in its initial plane. A deviation of the crack, which is often
observed experimentally, involves an increase in the energy parameter J. This
may be also an explanation for the numerical underestimation of this parameter.
2.4
o 2.2
2 2
5
2 1.6O)
•U 1.4
o> 1.2
1
0 200 400 600 800
Applied load P (N/mm)
Fig. 12. Void growth ratio vs applied load: the node release technique.
750
_ 600
E
£
z 450
ffl
S’ 300-*-1 c
150
0
0 0.2 0.4 0.6 0.8 1 1.2 1.4
Crack extension (mm)
Fig. 13. Energy parameter J vs crack extension (BM case): comparison between experimental and
numerical results.
Conclusions. The main results of this study may be summarised as follows:
1. In terms of load-displacement curves, when considering the BM
configuration, numerical data are in good agreement with experimental values,
confirming the validity of the numerical modeling (meshing, material behaviour,
boundary conditions, etc).
2. Concerning the bi- and trimetallic specimens, a similar evolution of their
global behavior has been observed in terms of load-displacement response, as
well as in terms of J-integral or CTOD results.
3. Concerning the trimetallic specimen, a linear dependence of the CTOD
parameter upon the J -integral has been observed. It is noteworthy that the BM
(R/Ro)c=2.23
m
ISSN 0556-171X. npoôëeMbi npounocmu, 2004, N 4 77
A. Imad, M. Nait Abdelaziz, G. Mesmacque
provides a major contribution to the total CTOD value, because of its lower
mechanical strength.
4. The different cases lead to a globally similar evolution of CTOD, when
plotted versus the ./-integral, indicating that these two parameters are not really
affected by a change in the specimen configuration.
5. The evolution of the void growth rate parameter R /R 0 is significantly
different since it is very sensitive to the local stress and strain fields and can be
used for prediction of both crack initiation and crack propagation. Therefore, this
parameter (and more generally, the local approach) can be applied as an
alternative and/or complementary tool for the fracture analysis of mismatched
welded joints.
Acknowledgement. This research was supported by the Mechanics and
Technology Department, Les Renardières Research Center, Electricité de France
(EDF).
Р е з ю м е
Виконано числовий розрахунок параметрів в’язкого руйнування компакт
них зразків, що моделюють зварне з ’єднання внапуск. Досліджували моно-,
бі- та триметалічні конфігурації компактних зразків із метою порівняння
глобальних (./-інтеграл та розкриття вістря тріщини) і локального (модель
Райса-Трейсі) підходів. Показано, що такі зміни конфігурації зразків не
впливають на глобальні параметри, в той час як локальний параметр -
коефіцієнт росту пор R /R 0 - дуже чутливий до зміни полів напружень і
деформацій в околі вістря тріщини. Пропонується напрямок поширення
тріщини у випадку зварного з ’єднання внапуск прогнозувати по розподілу
параметра R/R 0 в околі вістря тріщини.
1. J. Rice, “Mathematical analysis in the mechanics of fracture,” in: H. Liebowitz
(Ed.), Fracture, Academic Press (1968), Vol. 2, pp. 191-311.
2. Y. Lai and R. A Ainsworth, “A /-integral estimation method for cracks in
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A Ductile Tear Fracture Analysis
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Received 11. 03. 2004
ISSN 0556-171X. Проблемы прочности, 2004, № 4 79
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| id | nasplib_isofts_kiev_ua-123456789-47101 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 0556-171X |
| language | English |
| last_indexed | 2025-11-28T23:07:02Z |
| publishDate | 2004 |
| publisher | Інститут проблем міцності ім. Г.С. Писаренко НАН України |
| record_format | dspace |
| spelling | Imad, A. Nait Abdelaziz, М. Mesmacque, G. 2013-07-09T18:20:20Z 2013-07-09T18:20:20Z 2004 A Ductile Tear Fracture Analysis of Lap Welded Joints / A. Imad, M. Nait Abdelaziz, G. Mesmacque // Проблемы прочности. — 2004. — № 4. — С. 68-79. — Бібліогр.: 19 назв. — англ. 0556-171X https://nasplib.isofts.kiev.ua/handle/123456789/47101 539.4 Numerical analysis of the ductile fracture of lap welded joints has been performed for a standard CT specimen. Mono-, bi- and trimetallic CT configurations were studied in order to compare the J-integral and CTOD global approaches with a local approach (Rice and Tracey model). It is found that the above change in configuration has no impact on evolution of the global parameters, while the void growth ratio R/R is very sensitive to the stress and strain fields around the crack tip. Furthermore, using the parameter R/Ro distribution at the crack tip, allowed us to predict the crack propagation direction in the case of lap welded joints. Выполнен численный расчет параметров вязкого разрушения компактных образцов, моделирующих сварное соединение внахлестку. Исследовались моно-, би- и триметаллические конфигурации компактных образцов с целью сравнения глобальных (J-интеграл и раскрытие вершины трещины) и локального (модель Райса-Трейси) подходов. Показано, что такие изменения конфигурации образцов не влияют на глобальные параметры, в то время как локальный параметр - коэффициент роста пор R/R0 - весьма чувствителен к изменению полей напряжений и деформаций в окрестности вершины трещины. Предлагается направление распространения трещины в случае сварного соединения внахлестку прогнозировать по распределению параметра R/R0 в окрестности вершины трещины. Виконано числовий розрахунок параметрів в’язкого руйнування компактних зразків, що моделюють зварне з ’єднання внапуск. Досліджували моно-, бі- та триметалічні конфігурації компактних зразків із метою порівняння глобальних (J-інтеграл та розкриття вістря тріщини) і локального (модель Райса-Трейсі) підходів. Показано, що такі зміни конфігурації зразків не впливають на глобальні параметри, в той час як локальний параметр - коефіцієнт росту пор R/R0 - дуже чутливий до зміни полів напружень і деформацій в околі вістря тріщини. Пропонується напрямок поширення тріщини у випадку зварного з ’єднання внапуск прогнозувати по розподілу параметра R/R0 в околі вістря тріщини. This research was supported by the Mechanics and Technology Department, Les Renardières Research Center, Electricité de France (EDF). en Інститут проблем міцності ім. Г.С. Писаренко НАН України Проблемы прочности Научно-технический раздел A Ductile Tear Fracture Analysis of Lap Welded Joints Анализ вязкого сдвига в сварных соединениях внахлестку Article published earlier |
| spellingShingle | A Ductile Tear Fracture Analysis of Lap Welded Joints Imad, A. Nait Abdelaziz, М. Mesmacque, G. Научно-технический раздел |
| title | A Ductile Tear Fracture Analysis of Lap Welded Joints |
| title_alt | Анализ вязкого сдвига в сварных соединениях внахлестку |
| title_full | A Ductile Tear Fracture Analysis of Lap Welded Joints |
| title_fullStr | A Ductile Tear Fracture Analysis of Lap Welded Joints |
| title_full_unstemmed | A Ductile Tear Fracture Analysis of Lap Welded Joints |
| title_short | A Ductile Tear Fracture Analysis of Lap Welded Joints |
| title_sort | ductile tear fracture analysis of lap welded joints |
| topic | Научно-технический раздел |
| topic_facet | Научно-технический раздел |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/47101 |
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