Effect of Preliminary Torsional Strain on Low-Cycle Fatigue of Q345B Structural Steel
Effect of preliminary torsional strain on low-cycle fatigue of Q345B steel was studied. The specimens were first 0, 180, and 360° twisted, then the low-cycle fatigue of Q345B steel was evaluated in the strain range of 0.3–0.8% by the method of axisymmetrical strain. The cycling response, cyclic stre...
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Інститут проблем міцності ім. Г.С. Писаренко НАН України
2019
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| Цитувати: | Effect of Preliminary Torsional Strain on Low-Cycle Fatigue of Q345B Structural Steel / X.L. Hu, Y.J. Liu, C.X. Huang, Q.Y. Wang // Проблеми міцності. — 2019. — № 1. — С. 154-162. — Бібліогр.: 17 назв. — англ. |
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irk-123456789-1883132023-02-23T01:27:12Z Effect of Preliminary Torsional Strain on Low-Cycle Fatigue of Q345B Structural Steel Hu, X.L. Liu, Y.J. Huang, C.X. Wang, Q.Y. Научно-технический раздел Effect of preliminary torsional strain on low-cycle fatigue of Q345B steel was studied. The specimens were first 0, 180, and 360° twisted, then the low-cycle fatigue of Q345B steel was evaluated in the strain range of 0.3–0.8% by the method of axisymmetrical strain. The cycling response, cyclic stress–strain relationship, strain–life relationship, fatigue life prediction model, and seismic stability at different torsion angles were obtained and analyzed. The strain–life curve is shown to slope down as a power function. The fatigue life comes down with preliminary torsional strain at a constant level. The cycling response varied from cyclic hardening to cyclic softening in preliminary torsion, and the cyclic hardening rate increased linearly with the strain amplitude. The parameters of the Coffin–Manson relation are corroborated with experimental data. After heat treatment, the seismic stability of the material is improved, with torsional strain greatly reducing this characteristic. Electron microscope examination of fatigue fracture revealed a fatigue crack initiating on the surface of the specimen. The propagating crack deviated from its direction, and plasticity of the material dropped as a result of preliminary torsional strain. Изучено влияние деформации предварительного кручения на малоцикловую усталость стали Q345B. Вначале образцы скручивали на 0, 180 и 360°, затем методом осесимметричной деформации определяли малоцикловую усталость стали Q345B в диапазоне деформаций 0.3 0.8%. Получены и проанализированы характеристика циклических изменений, зависимость циклического изменения напряжения от деформации, зависимость деформация долговечность, модель прогнозирования усталостной долговечности и сейсмостойкость при различных углах кручения. Показано, что кривая деформация долговечность идет вниз и описывается степенной функцией. Усталостная долговечность снижается с увеличением деформации предварительного кручения при постоянном уровне последней. Характеристика циклических изменений варьировала от циклического упрочнения до циклического разупрочнения при кручении, скорость циклического упрочнения возрастала линейно с повышением амплитуды деформации. Параметры зависимости Коффина Мэнсона подтверждаются экспериментальными данными. После термообработки сейсмостойкость материала улучшается, при этом деформация предварительного кручения существенно снижает ее. Электронно-микроскопическое исследование усталостного разрушения выявило зарождение усталостной трещины на поверхности образца. Растущая трещина отклонялась от своего направления, пластичность материала снижалась в результате деформации предварительного кручения. Вивчено вплив деформації попереднього кручення на малоціклову втому стали Q345B. Спочатку зразки скручували на 0, 180 і 360 °, потім методом вісесиметричної деформації визначали малоціклову втому стали Q345B в діапазоні деформацій 0.3-0.8%. Отримано і проаналізовано характеристику циклічних змін, залежність циклічної зміни напржень від деформації, залежність деформація-довговічність, модель прогнозування втомної довговічності і сейсмостійкості при різних кутах кручення. Показано, що крива деформація - довговічність йде вниз і описується ступеневою функцією. Втомна довговічність знижується зі збільшенням деформації попереднього кручення при постійному рівні останньої. Характеристика циклічних змін варіювала від циклічного зміцнення до циклічного знеміцнення при крученні, швидкість циклічного зміцнення зростала лінійно з підвищенням амплітуди деформації. Параметри залежності Коффина-Менсона підтверджуються експериментальними даними. Після термообробки сейсмостійкість матеріалу поліпшується, при цьому деформація попереднього кручення істотно знижує її. Електронно-мікроскопічне дослідження втомного руйнування виявило зародження втомної тріщини на поверхні зразка. Зростаюча тріщина відхилялася від свого напрямку, пластичність матеріалу знижувалася в результаті деформації попереднього кручення. 2019 Article Effect of Preliminary Torsional Strain on Low-Cycle Fatigue of Q345B Structural Steel / X.L. Hu, Y.J. Liu, C.X. Huang, Q.Y. Wang // Проблеми міцності. — 2019. — № 1. — С. 154-162. — Бібліогр.: 17 назв. — англ. 0556-171X http://dspace.nbuv.gov.ua/handle/123456789/188313 539.4 en Проблемы прочности Інститут проблем міцності ім. Г.С. Писаренко НАН України |
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Научно-технический раздел Научно-технический раздел Hu, X.L. Liu, Y.J. Huang, C.X. Wang, Q.Y. Effect of Preliminary Torsional Strain on Low-Cycle Fatigue of Q345B Structural Steel Проблемы прочности |
| description |
Effect of preliminary torsional strain on low-cycle fatigue of Q345B steel was studied. The specimens were first 0, 180, and 360° twisted, then the low-cycle fatigue of Q345B steel was evaluated in the strain range of 0.3–0.8% by the method of axisymmetrical strain. The cycling response, cyclic stress–strain relationship, strain–life relationship, fatigue life prediction model, and seismic stability at different torsion angles were obtained and analyzed. The strain–life curve is shown to slope down as a power function. The fatigue life comes down with preliminary torsional strain at a constant level. The cycling response varied from cyclic hardening to cyclic softening in preliminary torsion, and the cyclic hardening rate increased linearly with the strain amplitude. The parameters of the Coffin–Manson relation are corroborated with experimental data. After heat treatment, the seismic stability of the material is improved, with torsional strain greatly reducing this characteristic. Electron microscope examination of fatigue fracture revealed a fatigue crack initiating on the surface of the specimen. The propagating crack deviated from its direction, and plasticity of the material dropped as a result of preliminary torsional strain. |
| format |
Article |
| author |
Hu, X.L. Liu, Y.J. Huang, C.X. Wang, Q.Y. |
| author_facet |
Hu, X.L. Liu, Y.J. Huang, C.X. Wang, Q.Y. |
| author_sort |
Hu, X.L. |
| title |
Effect of Preliminary Torsional Strain on Low-Cycle Fatigue of Q345B Structural Steel |
| title_short |
Effect of Preliminary Torsional Strain on Low-Cycle Fatigue of Q345B Structural Steel |
| title_full |
Effect of Preliminary Torsional Strain on Low-Cycle Fatigue of Q345B Structural Steel |
| title_fullStr |
Effect of Preliminary Torsional Strain on Low-Cycle Fatigue of Q345B Structural Steel |
| title_full_unstemmed |
Effect of Preliminary Torsional Strain on Low-Cycle Fatigue of Q345B Structural Steel |
| title_sort |
effect of preliminary torsional strain on low-cycle fatigue of q345b structural steel |
| publisher |
Інститут проблем міцності ім. Г.С. Писаренко НАН України |
| publishDate |
2019 |
| topic_facet |
Научно-технический раздел |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/188313 |
| citation_txt |
Effect of Preliminary Torsional Strain on Low-Cycle Fatigue of Q345B Structural Steel / X.L. Hu, Y.J. Liu, C.X. Huang, Q.Y. Wang // Проблеми міцності. — 2019. — № 1. — С. 154-162. — Бібліогр.: 17 назв. — англ. |
| series |
Проблемы прочности |
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2025-07-16T10:19:09Z |
| last_indexed |
2025-07-16T10:19:09Z |
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1837798419433783296 |
| fulltext |
UDC 539.4
Effect of Preliminary Torsional Strain on Low-Cycle Fatigue of Q345B
Structural Steel
X. L. Hu,
a
Y. J. Liu,
b,1
C. X. Huang,
b,c
and Q. Y. Wang
a,b,d,2
a Key Laboratory of Underground Science and Engineering, Ministry of Education, College of
Architecture & Environment, Sichuan University, Chengdu, China
b Failure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan
Province, College of Architecture & Environment, Sichuan University, Chengdu, China
c School of Aeronautics and Astronautics, Sichuan University, Chengdu, China
d School of Urban and Rural Construction, Chengdu University, Chengdu, China
1 liuyongjie@scu.edu.cn
2 wangqy@scu.edu.cn
Effect of preliminary torsional strain on low-cycle fatigue of Q345B steel was studied. The specimens
were first 0, 180, and 360� twisted, then the low-cycle fatigue of Q345B steel was evaluated in the
strain range of 0.3–0.8% by the method of axisymmetrical strain. The cycling response, cyclic
stress–strain relationship, strain–life relationship, fatigue life prediction model, and seismic stability
at different torsion angles were obtained and analyzed. The strain–life curve is shown to slope down
as a power function. The fatigue life comes down with preliminary torsional strain at a constant
level. The cycling response varied from cyclic hardening to cyclic softening in preliminary torsion,
and the cyclic hardening rate increased linearly with the strain amplitude. The parameters of the
Coffin–Manson relation are corroborated with experimental data. After heat treatment, the seismic
stability of the material is improved, with torsional strain greatly reducing this characteristic.
Electron microscope examination of fatigue fracture revealed a fatigue crack initiating on the surface
of the specimen. The propagating crack deviated from its direction, and plasticity of the material
dropped as a result of preliminary torsional strain.
Keywords: Q345B steel, preliminary torsion, low-cycle fatigue, fatigue life, seismic
stability.
Introduction. Q345B structural steel is often used as the main material of critical
structures for its high strength, low cost, excellent welding property and toughness. Its
stability and toughness play a crucial role in the safety of engineering structures. Q345B
steel structures are often subjected to complex alternating loads during service, such as
earthquake, wind, dynamic loads caused by the traffic, and so on. Fatigue failure is the
main cause of failure in these structures [1], and sudden fatigue fracture may cause heavy
losses. Therefore, the study of fatigue behavior of Q345B steel and its structure is a very
important part of the engineering field. It is of great significance to ensure the reliability
and safety of the engineering structure.
In engineering applications, the steel structural component is usually made by plastic
processing, and the bulk material or its surface have preliminary strains due to twisting,
bending, stretching, compression or various combination deformation [2]. Moreover, the
steel structure will inevitably suffer torsional stresses in use, which may cause plastic
deformation. By now, the low-cycle fatigue behavior of structural steels such as high-
strength steel [3], Q345B [4], and 45 steel [5] have been studied in detail. However, less
attention has been paid to the effect of pre-strain on the fatigue properties of structural
steels. The pre-strain may cause the shear stress and the normal stress on the slip surface of
the material. The former may increase the dislocation density and strengthen it, while the
© X. L. HU, Y. J. LIU, C. X. HUANG, Q. Y. WANG, 2019
154 ISSN 0556-171X. Ïðîáëåìè ì³öíîñò³, 2019, ¹ 1
latter will cause plastic damage [6]. Miao et al. [7] and Zheng et al. [8] studied the fatigue
properties of steels with different carbon content and low-alloy steels after tensile
pre-strain, found that the pre-tensile strengthening had a great effect on the fatigue property
of carbon steel, and the incomplete plastic deformation and strain hardening caused by
tension had an adverse effect on the test results. Wu and Wang et al. [9, 10] studied the
effect of pre-torsion strain on fatigue properties of 45 steel, including cyclic stress-strain
characteristics, cyclic hardening and softening properties and low-cycle fatigue life, found
that fatigue life was reduced after pre-torsion strain and cyclic stress increased with
increase of pre-torsion strain. At present, there is no research report on the effect of
pre-strain on fatigue behavior of Q345B structural steel.
In this paper, Q345B steel was pre-twisted to different angles and the effects of
preliminary torsional strain on low-cycle fatigue and seismic performance of Q345B steel
were studied.
1. Test Material and Specimen. The commercial hot-rolled Q345B low-alloy steel of
thickness of 20 mm was used in this study. Its chemical component (wt.%) is 0.16 C, 0.35
Si, 1.34 Mn, 0.11 S, 0.22 P, and Fe (remain). The material was heat-treated as shown in
Fig. 1. The microstructure of the heat treated Q345B steel is depicted in Fig. 2. It can be
seen that the material is mainly ferrite (black area), with a low share of pearlite (white
area). The main mechanical properties are as follows; the elastic modulus E � 205 GPa,
yield strength � s � 308 MPa, and tensile strength � b � 495 MPa.
The fatigue specimen was designed according to the standard GB/T 15248-2008 [11]
and machined by a CNC machine. The dimensions of the fatigue specimen are shown in
Fig. 3. The surface of the specimen was ground and polished with SiC abrasive papers up
to a final grade of 1200 and abrasive paste (minimum grain size 7 �m), respectively.
2. Test Methods. Torsion tests were carried out via an RNJ-500 type microcomputer-
controlled electronic torsion-testing machine.
Tensile tests were conducted using a SHIMADZU AGX-100 universal testing machine.
Fatigue tests were carried out by a SHIMADZU EHF-EM200k2-040 fatigue test machine
Effect of Preliminary Torsional Strain ...
ISSN 0556-171X. Ïðîáëåìè ì³öíîñò³, 2019, ¹ 1 155
Fig. 1. Heat treatment process. Fig. 2. Microstructure of Q345B steel.
Fig. 3. The dimension of the specimen.
at room temperature. The strain was controlled by an axial extensometer with a span of
12.5 mm. The loading strain rate was 0.005 s�1 , and strain amplitudes were 0.4, 0.5, 0.6,
0.7, and 0.8%. The loading frequency under different strain amplitudes were calculated
according to the formula of strain rate expression as follows:
� .�
� �
�� �
�
�
�
�
�
�
�
�
t T
f
a
a
4
4 (1)
3. Results and Discussion.
3.1. Uniaxial Tensile Test. Tensile tests were done for specimens with pre-torsion
angles of 90, 180, 270, and 360�, respectively, and obtained corresponding mechanical
properties are shown in Table 1. It can be seen that with an increase in the pre-torsion
angle, the elastic modulus decreased, while the yield strength and tensile strength increased.
The tensile curves in the front part are shown in Fig. 4, where the uniaxial tensile behavior
of the material is shown to sharply change after pre-torsion, while the yield plateau has
disappeared.
3.2. Cyclic Response Characteristic. Fatigue tests were carried out on specimens
without pre-torsion (0�) and with pre-torsion angels of 180 and 360�, respectively, in the
low-cycle range. The cyclic characteristic curves under different strain amplitudes are
shown in Fig. 5. It can be seen that the material without pre-torsion firstly had cyclic
hardening effect [12], and then entered the stable stress stage until failure. In order to resist
the external load, the dislocation arrangement of the material would evolve towards the
direction of improving the overall property. Cyclic hardening is mainly caused by the
X. L. Hu, Y. J. Liu, C. X. Huang, and Q. Y. Wang
156 ISSN 0556-171X. Ïðîáëåìè ì³öíîñò³, 2019, ¹ 1
T a b l e 1
Mechanical Properties of Q345 Steel
Pre-torsion angle (deg) E, GPa �s , MPa �b , MPa
0 205 308 495
90 138 358 514
180 128 401 525
360 112 459 576
Fig. 4. Uniaxial tensile test.
dislocation multiplication during cycling [13]. While the material with pre-torsion strain
firstly showed cyclic softening. The reason for cyclic softening was that the pre-torsion
strain leaded to dislocation rearrangement into a structure with lower density and internal
stress [13].
The cyclic hardening rate H can be used to describe the degree of hardening at the
initial loading stage, as in [14]:
H
a sat a
a
�
�� �
�
, ,
,
,
1
1
(2)
where � a,1 and � a sat, are the stress amplitude values in the first and half life cycle. The
relation between strain amplitude and cyclic hardening rate are shown in Fig. 6. It implies
that the cyclic hardening rate increased linearly with the strain amplitude.
ISSN 0556-171X. Ïðîáëåìè ì³öíîñò³, 2019, ¹ 1 157
Effect of Preliminary Torsional Strain ...
Fig. 5. Cyclic response curves.
Fig. 6. Cyclic hardening rate.
3.3. Strain–Life Curve. The relationships between strain amplitude and fatigue life
were obtained as shown in Fig. 5. Under the same strain amplitude, the fatigue life of the
specimen sujected to preliminary torsional load was obviously lower than that of the
untreated one, and with an increase in the pre-torsion angle, the related fatigue life
decreased. As the cyclic loading amplitude increased, the fatigue life decreased gradually,
and the dependence between the strain amplitude and fatigue life was properly described
by a power function.
According to the Coffin–Manson formula [15, 16], the relationship between strain and
life was shown as follows:
� � �� � � �
�t e p f
f
b
f f
c
E
N N
2 2 2
2 2� � �
�
� �( ) ( ) , (3)
where �� f , b, �� f , and c are fatigue strength coefficient, fatigue strength index, fatigue
plasticity coefficient, and fatigue plasticity index, respectively. The corresponding values
could be obtained by fitting the experimental data. The resulting expressions are listed as
Eqs.(3)–(5), respectively, and related curves are shown in Fig. 7. The data in the above plot
are seen to be evenly distributed on both sides of the fitting curves, showing that the latter
curves are in good agreement with the experimental data:
�a f fN N0
0171 0 500163 2 03965 2�
� �� �. ( ) . ( ) ,. .
(4)
�a f fN N180
0107 0 51400092 2 01132 2�
� �� �. ( ) . ( ) ,. .
(5)
�a f fN N360
0 075 0 55400068 2 00866 2�
� �� �. ( ) . ( ) .. .
(6)
3.4. Seismic Performance Analysis. When buildings are subjected to earthquake
loads, most of the energy is absorbed by the steel structures. Therefore, energy consumption
of steel directly affects the seismic performance of buildings. Previous studies pointed out
that [13], when the seismic load reached about 100 cycles, the building was most likely to
158 ISSN 0556-171X. Ïðîáëåìè ì³öíîñò³, 2019, ¹ 1
X. L. Hu, Y. J. Liu, C. X. Huang, and Q. Y. Wang
Fig. 7. Strain–life curve.
collapse. Assuming that the fatigue life of the material was N f � 100, the greater the cyclic
energy absorption rate was, the stronger the energy dissipation capacity of the material.
Upon the substituion of N f � 100 into Eqs. (3)–(5), strain values could be obtained as
�a0� � 3.46%, �a180� � 1.26%, and �a360� � 0.92%. According to the experimental data,
when the cyclic cycle reached 100 cycles, the stress and strain were basically stable.
Therefore, the value of � a could be obtained according to the �a value and then values
of � �a t� were calculated. The energy absorption rate of the heat-treated Q345B steel
without pre-torsion was 39.90 J cm� 3, which was higher than those of as-received Q345B
(12.89 J cm� 3), showing that it had better anti-seismic performance. The energy absorption
rates of the material with pre-torsion angles of 180 and 360� were only 12.04 and 3.53
J cm� 3, which indicated the reduction by 69.8 and 91.2%, respectively, as compared to the
untreated one. Therefore, the preliminary torsional strain greatly reduced the seismic
performance of the material.
3.5. Crack Initiation Life. In practical engineering, if the initiated crack reached its
propagation stage, the material is considered to lose its load-bearing ability. For the material
with stable cyclic stress-strain stage, the accumulated damages are characterized by the
cyclic stress and strain characteristics. When the material entered the crack propagation
stage, the remaining life could be estimated based the relationship between the fatigue
crack and the damage evolution [9].
According to the cyclic characteristic curves given in Fig. 5, the point where the stress
dropped sharply was considered as the boundary between the fatigue crack initiation and
propagation [17]. In this paper, such point was chosen as value at which the constant stress
value dropped by 5%. The relationship between the crack initiation life as a percentage of
the total life ( N Ni f ) and the strain amplitude are shown in Fig. 8. The variation of the
N Ni f with the loading strain amplitude exhibited different patterns: it decreased linearly
for the untreated material, slightly fluctuated in the range from 80 to 90% for the one
subjected to pre-torsion angle of 180°, and increased linearly for the one with pre-torsion
angle of 360�.
3.6. Fatigue Crack Initiation and Propagation Mechanisms. The fracture surfaces of
broken specimens were investigated by a scanning electron microscope (SEM) as shown in
Fig. 9. From the macroscopic features, it could be seen that each fracture surface could be
ISSN 0556-171X. Ïðîáëåìè ì³öíîñò³, 2019, ¹ 1 159
Effect of Preliminary Torsional Strain ...
Fig. 8. Cyclic hardening rate.
divided into three regions: crack initiation area (I), propagation area (II), and final fracture
area (III). The fatigue crack originated from the specimen surface and the crack initiation
area was bright and smooth. The crack propagation area was relatively smooth, and the part
near the final fracture area was rough with secondary cracks and fatigue striations. There
were numerous dimples in the final fracture area, indicating a ductile fracture pattern. The
cross section of the specimen without pre-torsion was smoother than those with
pre-torsions, and the number and height of fatigue striations in the final fracture area
increased with the pre-torsion angle. The pre-torsion caused deflection of the fatigue crack
propagation direction.
In low-cycle fatigue, fatigue cracks were usually nucleated from the surface of the
specimen. With an increase in a cyclic load, many microcracks formed macrocracks by the
coalescence and propagation mechanisms. With the propagation of macrocracks, the
effective bearing area of the fracture section decreased gradually and the stress increased
relatively. When the stress reached the fracture limit of the material, the specimen would
fail instantaneously. The number of secondary cracks in the pre-torsion specimens was
significantly higher than that in specimens without pre-torsion, and the direction of these
secondary cracks was approximately perpendicular to the crack propagation direction. In
the final fracture areas of the pre-torsion specimens, the sizes of dimples were relatively
smaller and the concave-convex morphologies were larger, which indicated that the
pre-torsion reduced the material plasticity.
160 ISSN 0556-171X. Ïðîáëåìè ì³öíîñò³, 2019, ¹ 1
X. L. Hu, Y. J. Liu, C. X. Huang, and Q. Y. Wang
Fig. 9. Fatigue fracture: (a) full view of fracture morphologies (0�); (b) crack initiation area (0�); (c) full
view of fracture morphologies (180�); (d) crack initiation area (180�); (e) full view of fracture
morphologies (360�); (f) crack initiation area (360�).
Conclusions. In this paper, low-cycle fatigue tests of Q345B structural steel specimens
subjected to preliminary torsional strain were carried out. The following conclusions can be
drawn based on the results obtained.
1. With an increase in the cyclic strain amplitude, the fatigue life decreased gradually,
and the strain-life curve decreased via a power function pattern. The fatigue limit of the
material is reduced by the preliminary torsional strain.
2. The original material exhibited a cyclic hardening, while specimens subjected to
pre-torsion showed a cyclic softening. The cyclic hardening rate increased linearly with the
strain amplitude.
3. By calculating the energy absorption rate of Q345B steel, it was concluded that its
seismic performance was improved by the heat treatment and strongly reduced by the
pre-torsion strain.
4. The variation of the N Ni f with the strain amplitude decreased linearly for the
material without pre-torsion, remained within the range from 80 to 90% for the pre-torsion
angle of 180� one, and increased linearly for the pre-torsion angle of 360�.
5. Fatigue cracks originated from the specimen surface, and the fracture surface could
be divided into three regions: crack initiation, crack propagation, and final rupture areas.
The pre-torsion caused deflection of the crack propagation direction and reduced the
material plasticity.
Acknowledgments. The authors gratefully acknowledge the financial support from the
National Science Foundation of China (NSFC-11172188, 11772209), the Program for
Changjiang Scholars and Innovative Research Team (IRT14R37), and the International
Cooperation Project of Sichuan Provincial Science and Technology Department, China
(2016HH0037).
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Received 15. 03. 2018
162 ISSN 0556-171X. Ïðîáëåìè ì³öíîñò³, 2019, ¹ 1
X. L. Hu, Y. J. Liu, C. X. Huang, and Q. Y. Wang
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/ENU (Use these settings to create Adobe PDF documents best suited for high-quality prepress printing. Created PDF documents can be opened with Acrobat and Adobe Reader 5.0 and later.)
>>
/Namespace [
(Adobe)
(Common)
(1.0)
]
/OtherNamespaces [
<<
/AsReaderSpreads false
/CropImagesToFrames true
/ErrorControl /WarnAndContinue
/FlattenerIgnoreSpreadOverrides false
/IncludeGuidesGrids false
/IncludeNonPrinting false
/IncludeSlug false
/Namespace [
(Adobe)
(InDesign)
(4.0)
]
/OmitPlacedBitmaps false
/OmitPlacedEPS false
/OmitPlacedPDF false
/SimulateOverprint /Legacy
>>
<<
/AddBleedMarks false
/AddColorBars false
/AddCropMarks false
/AddPageInfo false
/AddRegMarks false
/ConvertColors /ConvertToCMYK
/DestinationProfileName ()
/DestinationProfileSelector /DocumentCMYK
/Downsample16BitImages true
/FlattenerPreset <<
/PresetSelector /MediumResolution
>>
/FormElements false
/GenerateStructure false
/IncludeBookmarks false
/IncludeHyperlinks false
/IncludeInteractive false
/IncludeLayers false
/IncludeProfiles false
/MultimediaHandling /UseObjectSettings
/Namespace [
(Adobe)
(CreativeSuite)
(2.0)
]
/PDFXOutputIntentProfileSelector /DocumentCMYK
/PreserveEditing true
/UntaggedCMYKHandling /LeaveUntagged
/UntaggedRGBHandling /UseDocumentProfile
/UseDocumentBleed false
>>
]
>> setdistillerparams
<<
/HWResolution [2400 2400]
/PageSize [612.000 792.000]
>> setpagedevice
|