CN109933817A - The creep incubation period prediction technique of the contained parameter unrelated with load is considered under the conditions of elastic transient creep - Google Patents
The creep incubation period prediction technique of the contained parameter unrelated with load is considered under the conditions of elastic transient creep Download PDFInfo
- Publication number
- CN109933817A CN109933817A CN201711350811.4A CN201711350811A CN109933817A CN 109933817 A CN109933817 A CN 109933817A CN 201711350811 A CN201711350811 A CN 201711350811A CN 109933817 A CN109933817 A CN 109933817A
- Authority
- CN
- China
- Prior art keywords
- creep
- stress
- unit
- incubation period
- load
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention discloses consider that the creep incubation period prediction technique of the contained parameter unrelated with load proposes the creep incubation period prediction model for considering to restrain effect on the basis of Davies work under the conditions of a kind of elastic transient creep.Using ductility exhaustion damage model, introduces contained parameter Q* unrelated with load and calculate the creep incubation period for considering to restrain effect.Apply main load using compact tensile specimen (CT) and carry out creep simulation experiment, beneficial effects of the present invention: succinctly can effectively predict creep incubation period under the conditions of elastic transient creep in the structure.
Description
Technical field
The present invention relates to the thermal structure for considering the contained parameter unrelated with load is compacted under the conditions of elastic transient creep
Become the evaluation of incubation period engineering critical, exactly determine in the structure there are face crack and is under elastic transient creep stress condition
When, evaluate the creeping crack initiating life of this thermal structure.
Background technique
Energy resource structure based on fire coal is one of the main reason of China's haze weather, and coal fired power generation be China at present most
Main generation mode, the trend is by long-term existence.Therefore, in addition to restructuring the use of energy, develop the ultra supercritical of high effect cleaning
(USC) unit is one of important channel of energy-saving and emission-reduction.However, the raising of vapor (steam) temperature and pressure and other parameters causes unit crucial
The Service Environment very severe of high-temperature pipe, it is various scarce that there are crackle, lack of penetration, weld blowhole and slag inclusions etc. especially in pipeline
It falls into, seriously threatens the safe operation of unit, need to carry out it accurate life appraisal of science.
In decades, for cracking member under high temperature, the development abroad review approach of a variety of high-temperature creep life-spans and
Method.Creep incubation period is the elapsed-time standards longest stage in creep process, and the Accurate Prediction of incubation period is for thermal structure
Creep life prediction is of great significance；The incubation period prediction model that Davies et al. is proposed based on toughness dissipation model considers
The integrality of creep process stress variation, but influence of the contained effect of structure to incubation period do not studied；It is close
Scientific research personnel has carried out a large amount of research for restraining influence of the effect to On Creep Crack Growth over year.Contained effect is widely deposited
It is in the high-temperature component fabricated, and significant impact is caused to the service life of component.It is compacted to be largely directed to high temperature
The research for restraining effect in the case of change is also unfolded extensively.Therefore the creep incubation period prediction model for considering to restrain effect is established, it can
With the more accurate creep incubation period for completely assessing Combined Loading structure.
Summary of the invention
The present invention proposes the creep incubation period prediction model for considering to restrain effect on the basis of Davies works.Benefit
With ductility exhaustion damage model, introduces and consider that Q* calculates the creep incubation period for considering to restrain effect.Use compact tensile specimen
(CT) apply main load and carry out creep simulation experiment.
The technical solution adopted to achieve the purpose of the present invention is:
The creep incubation period prediction side of the contained parameter unrelated with load is considered under the conditions of elastic transient creep of the invention
Method, comprising the following steps:
S1: establish model: the model includes CT sample ontology, and the middle part front end of the CT sample ontology is equipped with slot, slot
Rear portion be equipped with notch, be additionally provided with main load pin hole, lower main load pin hole, upper main load pin hole, lower master on CT sample ontology
Load pin hole is correspondingly arranged up and down, is separately positioned on the upper and lower ends of slot；
S2: it is inserted into precrack at notch rear portion first, slot, notch, precrack in the same plane, are existed using pin
Upper main load pin hole, lower main load pin hole apply main load, carry out high-temerature creep test；
S3: calculating can be obtained by creep finite element modelling and joined containing necessity required for effect CT sample incubation period is restrained
Number, under the condition of palsticity, calculating incubation period is mainly comprised the steps that
(1) the contained parameter Q under the conditions of transient creep is calculated first* RR, its calculation formula is:
(I) in: C* is the high temperature fracture parameter obtained using FEM calculation, and unit is MPamm (h)-1,
It is the opening stress value at the crackle forward position obtained using FEM calculation, unit is Mpa, and L is scalar distance, takes 1mm.
(I) in: σ22It is the opening stress value in the crackle forward position obtained using HRR stress field calculation, unit is MPa,
(I) and in (II): σ0It is the yield strength of material, unit is MPa, referring to document: (Zhao L, Xu L, Han Y,
Jing H.Two-parameter characterization of constraint effect induced by
specimen size on creep crack growth.Engng Fract Mech 2012；96:251–66.),It is compacted
Allergic effect becomes change rate, unit h-1, I related with material at high temperature creep attributenIt is dimensionless function related with n, in (II): r
It is spacing of the crackle rear portion tip to crackle forward position research point, unit is mm, and θ is crack tip angle, and n is nondimensional creep
Stress hardening index, n andReferring to document: (Zhao L, Jing H, Xu L, Han Y, Xiu J.Evaluation of
constraint effects on creep crack growth by experimental investigation and
numerical simulation.Engng Fract Mech 2012；96:251-66.),It is related with θ and n
Dimensionless function, In、Occurrence can be obtained with consulting literatures: (Shih, C.F..1983.Tables of
Hutchinson-Rice-Rosengren Singular Field Quantities.Brown University
Technical Report,MRL E-147.)；
(II) in: C (t) integral is the high temperature fracture parameter changed over time, and unit is MPamm (h)-1, calculate public
Formula:
Wherein: t is the time, and unit is h, and C* is the high temperature fracture parameter obtained using FEM calculation, unit MPa
mm·(h)-1, E ' is effective modulus of elasticity: E'=E/ (1- ν2), E is elasticity modulus, and ν is Poisson's ratio, and both E, ν are referring to text
It offers: (Zhao L, J1ng H, Xu L, Han Y, Xiu J.Evaluation of constraint effects on creep
crack growth by experimental investigation and numerical simulation.Engng
Fract Mech 2012；96:251-66.), K is stress intensity factor, and unit is MPa (m)0.5, calculation formula:
(III) in:
(III) in: P is main load, unit N；B is sample thickness, unit mm；A/W is precrack length ratio, a
It is precrack length, using the horizontal linear distance in the upper main load pin hole center of circle to precrack rear end, unit mm；W is
Nominal specimen width, using the upper main load pin hole center of circle to the horizontal linear distance of CT sample ontology rear end, unit mm；f(a/
It W) is CT sample geometrical factor, it is only related with a/W.
(2) transient creep equivalent stress is calculatedIts calculation formula is:
(IV) in:It is dimensionless function related with θ and n, occurrence can be obtained with consulting literatures:
Shih,C.F.. 1983.Tables of Hutchinson-Rice-Rosengren Singular Field
Quantities.Brown University Technical Report,MRL E-147.
(3) conversion time t is calculated using MATALAB softwareK-RR: meet at this moment:
Elastic stage damages aggregate-value:
(V) in: elastic equivalent stressIts calculation formula is:
Wherein:It is dimensionless function related with crack tip angle, θ and Poisson's ratio ν, can table look-up acquisition
(Webster,G.A.,1994.Fracturemechanicsinthecreeprange.JournalofStrainAnalysisfo
rEngineeringDesign29,215–223.)；
(V) in: MSFKFor the Multiaxial stress factor under elastic condition, calculated according to Cocks and Ashby relational expression:
Wherein: n is nondimensional creep stress hardenability value, and sinh is hyperbolic sine function, hkFor three axis of elastic stress
Degree, under elastic stress state:
Wherein: θ is crack tip angle, and ν is Poisson's ratio；
(4) transient creep stress field time lower incubation period t then is calculated using MATALAB softwarei, its calculation formula is:
(VI) in: d is to determine to split creep impairment before point when creep germinating occurs to reach 1 distance extended, unit mm,
That is the critical distance of creep germinating generation；
(VI) in: MSFRRFor the Multiaxial stress factor under the condition of palsticity, calculated according to Cocks and Ashby relational expression:
Sinh is hyperbolic sine function, hRRFor three axis degree of transient creep stress, under plastic stress state:
Wherein: mean stressUnit is MPa, its calculation formula is:
Wherein: σ11And σ33It is the stress value in the crackle forward position obtained using RRss stress field calculation, unit is MPa,
Wherein:It is dimensionless function related with θ and n, occurrence can be obtained with consulting literatures:
Shih,C.F..1983.Tables of Hutchinson-Rice-Rosengren Singular Field
Quantities.Brown University Technical Report,MRL E-147.。
Preferably, d takes the crystallite dimension of research material.
Preferably, describedThe finite element modelling of C* carries out calculating simulation using ABAQUS6.14,C*'s mentions
Take process the following steps are included:
(1) finite element model for initially setting up the CT sample of main tensile load load, is arranged high in material properties module
The rigid of stretching pin and pin hole is arranged contact in mesh module grid division in the lower resilient plastic creep parameters of temperature in module
Property contact, and be inserted into precrack in a model, set output parameter in analysis step module: stress value, fracture parameter C*
Value, is arranged tensile load and contained condition: including symmetric condition and rigid condition in payload module；
(2) task computation is submitted in operation module, obtains and contains creep stretching experiment calculated result, in destination file, from
Available fracture parameter C* in historical variable, in the available stress value of field variable
Compared with prior art, the beneficial effects of the present invention are:
The invention proposes creep incubation period prediction models under the conditions of modified elastic transient creep, with existing model phase
Than the design method can expand to original prediction model in the model containing contained effect, to propose a kind of simplification
Creep incubation period prediction technique under the conditions of elastic transient creep, therefore brief introduction effectively can predict elastic transient state in the structure
Creep incubation period under creep condition.
Detailed description of the invention
Fig. 1 compact tensile specimen (CT) stretches schematic diagram；
Wherein: 1-CT sample ontology, the upper main load pin hole of 2-, 3- slot, 4- notch, 5- precrack, main load pin under 6-
Hole.
Fig. 2 creeping crack germinates critical condition schematic diagram；
Fig. 3 is stress transmission schematic diagram.
Specific embodiment
The present invention is described in further detail below in conjunction with the drawings and specific embodiments.It should be appreciated that described herein
Specific embodiment be only used to explain the present invention, be not intended to limit the present invention.
Containing the creep incubation period prediction model of contained effect thermal structure under the conditions of elastic transient creep of the invention, such as scheme
Shown in 1, including CT sample ontology 1, the middle part front end of the CT sample ontology 1 are equipped with slot 3, and the rear portion of slot 3 is equipped with notch 4, CT
Main load pin hole 2, lower main load pin hole 6, upper main load pin hole 2, lower main about 6 load pin hole are additionally provided on sample ontology 1
It is correspondingly arranged, is separately positioned on the upper and lower ends of slot 3；
P92 high-temperature refractory steel is chosen, with B=10mm, the CT sample of W=20mm, a/W=0.5 are as research object, with master
Load p=1200N is as research load.Its main material attribute see the table below:
Containing the creep incubation period prediction technique of contained effect thermal structure under the conditions of elastic transient creep of the invention, including
Following steps:
S1: indentation, there is inserted into precrack 5, and slot 3, notch 4, precrack 5 are in the same plane.Using pin in upper master
Load pin hole 2, lower main load pin hole 6 apply main load, carry out high-temerature creep test；
S2: apply master in upper main load pin hole, lower main load pin hole using pin on the CT sample containing precrack
Load carries out high-temerature creep test；
S3: call parameter required for calculating CT sample incubation period can be obtained by crossing creep finite element modelling.In plastic strip
Under part, calculating incubation period is mainly comprised the steps that
(1) the contained parameter Q* under the conditions of transient creepRR:
Following data are extracted by finite element result:
The finite element model for initially setting up the CT sample of main tensile load load, is arranged under high temperature in material properties module
Resilient plastic creep parameters connect contacting the rigidity that setting stretches pin and pin hole in module in mesh module grid division
Touching, and it is inserted into precrack in a model, output parameter is set in analysis step module: stress value, fracture parameter C* integral
Value, is arranged tensile load and contained condition: including symmetric condition and rigid condition in payload module；
Task computation is submitted in operation module, obtains and contains creep stretching experiment calculated result, in destination file, from history
Available fracture parameter C*=0.000666564MPa mm h in variable‐1, in the available stress value of field variable
(a) it tables look-up:InThe material parameter ε of=4.99, P92 steelcrit=0.2；N=5.23 is being counted
Calculate creep stress and it is contained when, we take the distance r=d=0.05mm before splitting point.
(b) E'=E/ (1- ν2)=137362MPa
(c)
(d)
(e) it tables look-up:Elastic equivalent stress
(f)
The opening stress in crackle forward position:
(2) it tables look-up:
Transient creep equivalent stress
(3) conversion time tK-RR: it utilizesAnd MATALAB is calculated: tK-RR=0h
Elastic stage damages aggregate-value:
(4) germinating occurred under transient creep stress field is then calculated:
It tables look-up:
Mean stress:
Three axis degree of stress:
The Multiaxial stress factor:
D (mm) is that creep impairment reaches 1 distance extended, i.e. creep germinating hair before determining to split point when creep germinating occurs
Raw critical distance generally takes the crystallite dimension of research material, as shown in Figure 2.
Incubation period under the conditions of transient creep:
It is integrated using MATALAB solution: ti K-RR=1255h.
The above is only a preferred embodiment of the present invention, it is noted that for the common skill of the art
For art personnel, various improvements and modifications may be made without departing from the principle of the present invention, these improvements and modifications
Also it should be regarded as protection scope of the present invention.
Claims (3)
1. considering the creep incubation period prediction technique of the contained parameter unrelated with load under the conditions of elastic transient creep, feature exists
In, comprising the following steps:
S1: establish model: the model includes CT sample ontology, and the middle part front end of the CT sample ontology is equipped with slot, after slot
Portion is equipped with notch, is additionally provided with main load pin hole, lower main load pin hole, upper main load pin hole, lower main load on CT sample ontology
Pin hole is correspondingly arranged up and down, is separately positioned on the upper and lower ends of slot；
S2: first notch rear portion be inserted into precrack, slot, notch, precrack in the same plane, using pin in upper master
Load pin hole, lower main load pin hole apply main load, carry out high-temerature creep test；
S3: can obtain calculating by creep finite element modelling and contain call parameter required for restraining effect CT sample incubation period,
Under the condition of palsticity, calculating incubation period is mainly comprised the steps that
(1) the contained parameter Q under the conditions of transient creep is calculated first* RR, its calculation formula is:
(I) in: C* is the high temperature fracture parameter obtained using FEM calculation, and unit is MPamm (h)-1,It is to utilize
The opening stress value at crackle forward position that FEM calculation obtains, unit are Mpa, and L is scalar distance, take 1mm；
(I) in: σ22It is the opening stress value in the crackle forward position obtained using HRR stress field calculation, unit is MPa,
(I) and in (II): σ0It is the yield strength of material, unit is MPa,It is creep strain change rate, unit h-1, with material
Expect that high-temerature creep attribute is related, InIt is dimensionless function related with n, in (II): r is that crackle rear portion tip is ground to crackle forward position
Study carefully spacing a little, unit is mm, and θ is crack tip angle, and n is nondimensional creep stress hardenability value,It is and θ
Dimensionless function related with n；
(II) in: C (t) integral is the high temperature fracture parameter changed over time, and unit is MPamm (h)-1, calculation formula:
Wherein: t is the time, and unit is h, and C* is the high temperature fracture parameter obtained using FEM calculation, unit MPamm
(h)-1, E ' is effective modulus of elasticity: E'=E/ (1- ν2), E is elasticity modulus, and ν is Poisson's ratio, and K is stress intensity factor, unit
For MPa (m)0.5, calculation formula:
(III) in:
(III) in: P is main load, unit N；B is sample thickness, unit mm；A/W is precrack length ratio, and a is pre-
Crack length processed, using the horizontal linear distance in the upper main load pin hole center of circle to precrack rear end, unit mm；W is name
Specimen width, using the upper main load pin hole center of circle to the horizontal linear distance of CT sample ontology rear end, unit mm；F (a/W) is
CT sample geometrical factor, it is only related with a/W；
(2) transient creep equivalent stress is calculatedIts calculation formula is:
(IV) in:It is dimensionless function related with θ and n,
(3) conversion time t is calculated using MATALAB softwareK-RR: meet at this moment:
Elastic stage damages aggregate-value:
(V) in: elastic equivalent stressIts calculation formula is:
Wherein:It is dimensionless function related with crack tip angle, θ and Poisson's ratio ν；
(V) in: MSFKFor the Multiaxial stress factor under elastic condition, calculated according to Cocks and Ashby relational expression:
Wherein: n is nondimensional creep stress hardenability value, and sinh is hyperbolic sine function, hkFor three axis degree of elastic stress,
Under elastic stress state:
Wherein: θ is crack tip angle, and ν is Poisson's ratio；
(4) transient creep stress field time lower incubation period t then is calculated using MATALAB softwarei, its calculation formula is:
(VI) in: d is to determine to split creep impairment before point when creep germinating occurs to reach 1 distance extended, unit mm, i.e., compacted
Become the critical distance that germinating occurs；
(VI) in: MSFRRFor the Multiaxial stress factor under the condition of palsticity, calculated according to Cocks and Ashby relational expression:
Sinh is hyperbolic sine function, hRRFor three axis degree of transient creep stress, under plastic stress state:
Wherein: mean stressUnit is MPa, its calculation formula is:
Wherein: σ11And σ33It is the stress value in the crackle forward position obtained using RRss stress field calculation, unit is MPa,
Wherein:It is dimensionless function related with θ and n.
2. considering the creep incubation period of the contained parameter unrelated with load under the conditions of elasticity transient creep as described in claim 1
Prediction technique, which is characterized in that d takes the crystallite dimension of research material.
3. considering the creep incubation period of the contained parameter unrelated with load under the conditions of elasticity transient creep as described in claim 1
Prediction technique, which is characterized in that describedThe finite element modelling of C* carries out calculating simulation using ABAQUS6.14,
The extraction process of C* the following steps are included:
(1) finite element model for initially setting up the CT sample of main tensile load load, is arranged under high temperature in material properties module
Resilient plastic creep parameters connect contacting the rigidity that setting stretches pin and pin hole in module in mesh module grid division
Touching, and it is inserted into precrack in a model, output parameter is set in analysis step module: stress value, fracture parameter C* value,
Tensile load and contained condition are set in payload module: including symmetric condition and rigid condition；
(2) task computation is submitted in operation module, obtains and contains creep stretching experiment calculated result, in destination file, from history
Available fracture parameter C* in variable, in the available stress value of field variable
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711350811.4A CN109933817B (en) | 2017-12-15 | 2017-12-15 | Creep induction period prediction method considering constraint parameters irrelevant to load under elastic transient creep condition |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711350811.4A CN109933817B (en) | 2017-12-15 | 2017-12-15 | Creep induction period prediction method considering constraint parameters irrelevant to load under elastic transient creep condition |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109933817A true CN109933817A (en) | 2019-06-25 |
| CN109933817B CN109933817B (en) | 2022-10-21 |
Family
ID=66980059
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711350811.4A Active CN109933817B (en) | 2017-12-15 | 2017-12-15 | Creep induction period prediction method considering constraint parameters irrelevant to load under elastic transient creep condition |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109933817B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150323432A1 (en) * | 2014-05-09 | 2015-11-12 | Balhassn S. M. Ali | Pin loaded small one-bar specimen (OBS) |
| WO2016045024A1 (en) * | 2014-09-25 | 2016-03-31 | 华东理工大学 | Method for measuring and determining fracture toughness of structural material in high-temperature environment |
| CN105934797A (en) * | 2014-01-27 | 2016-09-07 | 泰拉能源公司 | Modeling for fuel element deformation |
| CN106529017A (en) * | 2016-11-08 | 2017-03-22 | 华南理工大学 | High-temperature creep deformation prediction and creep damage analysis method for high-chrome steel component |
| CN106644784A (en) * | 2016-12-31 | 2017-05-10 | 北京航空航天大学 | Turbine disc damage tolerance assessment method considering multiple parts and multiple failure modes |
-
2017
- 2017-12-15 CN CN201711350811.4A patent/CN109933817B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105934797A (en) * | 2014-01-27 | 2016-09-07 | 泰拉能源公司 | Modeling for fuel element deformation |
| US20150323432A1 (en) * | 2014-05-09 | 2015-11-12 | Balhassn S. M. Ali | Pin loaded small one-bar specimen (OBS) |
| WO2016045024A1 (en) * | 2014-09-25 | 2016-03-31 | 华东理工大学 | Method for measuring and determining fracture toughness of structural material in high-temperature environment |
| CN106529017A (en) * | 2016-11-08 | 2017-03-22 | 华南理工大学 | High-temperature creep deformation prediction and creep damage analysis method for high-chrome steel component |
| CN106644784A (en) * | 2016-12-31 | 2017-05-10 | 北京航空航天大学 | Turbine disc damage tolerance assessment method considering multiple parts and multiple failure modes |
Non-Patent Citations (1)
| Title |
|---|
| LIANYONG XU: "Characterizing crack growth behavior and damage evolution in P92 steel under creep-fatigue conditions", 《INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109933817B (en) | 2022-10-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Tan et al. | Load-independent creep constraint parameter and its application | |
| Wang et al. | Numerical investigation on the creep crack-tip constraint induced by loading configuration of specimens | |
| CN108733860A (en) | Creep induction period prediction method considering restraint effect under plastic transient creep condition | |
| CN108732032B (en) | Creep induction period prediction method containing residual stress under steady-state creep condition | |
| CN108733861B (en) | Creep induction period prediction method containing residual stress under plastic condition | |
| CN109932242A (en) | Creep induction period prediction method considering load-independent constraint parameters under steady-state creep condition | |
| CN109932251A (en) | Creep induction period prediction method considering load-independent constraint parameters under plastic condition | |
| CN108732034B (en) | Creep induction period prediction method containing residual stress under elastic transient creep condition | |
| CN109933820A (en) | The creep incubation period prediction technique of the contained parameter unrelated with load is considered under elastic condition | |
| CN109933817A (en) | The creep incubation period prediction technique of the contained parameter unrelated with load is considered under the conditions of elastic transient creep | |
| CN109933816B (en) | Creep induction period prediction method for coupling residual stress and constraint effect under elastic transient creep condition | |
| CN108733862A (en) | Creep induction period prediction method considering restraint effect under steady-state creep condition | |
| CN108732029B (en) | Creep induction period prediction method containing residual stress under elastic condition | |
| CN109933822A (en) | The creep incubation period prediction technique of the contained parameter unrelated with load is considered under the conditions of plasticity transient creep | |
| CN108731989A (en) | Creep induction period prediction method containing residual stress under plastic transient creep condition | |
| CN109933815B (en) | Creep induction period prediction method for coupling residual stress and constraint effect under steady-state creep condition | |
| CN108732033A (en) | Creep induction period prediction method considering restraint effect under elastic transient creep condition | |
| CN108732030A (en) | Creep induction period prediction method considering restraint effect under plastic condition | |
| CN108732031A (en) | Creep induction period prediction method considering restraint effect under elastic condition | |
| CN109933823B (en) | Creep induction period prediction method for coupling residual stress and constraint effect under plastic transient creep condition | |
| CN109932241B (en) | Creep induction period prediction method for coupling residual stress and constraint effect under plastic condition | |
| 石凯凯 et al. | Various theoretical models study of prediction fatigue crack growth | |
| CN109960819A (en) | Consider the incubation period prediction technique of contained center cracked tension sample | |
| FU et al. | Characterization of hydrogen gas pressure inner hydrogen induced crack cavity using fracture mechanics theory and finite element method | |
| Zhou et al. | Weibull stress solutions and applications under mixed mode I-II loading for 2-D cracks in elastic and elastic–plastic materials |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |