CN109900554B - A method of fracture toughness is calculated using indentation method - Google Patents

A method of fracture toughness is calculated using indentation method Download PDF

Info

Publication number
CN109900554B
CN109900554B CN201910249521.3A CN201910249521A CN109900554B CN 109900554 B CN109900554 B CN 109900554B CN 201910249521 A CN201910249521 A CN 201910249521A CN 109900554 B CN109900554 B CN 109900554B
Authority
CN
China
Prior art keywords
unloading
indentation
depth
fracture toughness
fitting
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.)
Active
Application number
CN201910249521.3A
Other languages
Chinese (zh)
Other versions
CN109900554A (en
Inventor
张玉财
陆敏捷
蒋文春
涂善东
张显程
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jiangsu Jiayian Technology Co ltd
Original Assignee
China University of Petroleum East China
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by China University of Petroleum East China filed Critical China University of Petroleum East China
Priority to CN201910249521.3A priority Critical patent/CN109900554B/en
Priority to PCT/CN2019/081981 priority patent/WO2020199235A1/en
Publication of CN109900554A publication Critical patent/CN109900554A/en
Application granted granted Critical
Publication of CN109900554B publication Critical patent/CN109900554B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/08Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/40Investigating hardness or rebound hardness
    • G01N3/42Investigating hardness or rebound hardness by performing impressions under a steady load by indentors, e.g. sphere, pyramid

Landscapes

  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)

Abstract

The invention belongs to fracture toughness test technical fields, provide a kind of method for calculating fracture toughness using indentation method, include the following steps: that (1) obtains material indentation and the relationship between unloading phase depth and load;(2) load displacement curve when being unloaded by material obtains plasticity residual depth, contact depth state parameter;It (3) include radial displacement correction factor and Berkovich pressure head non-axis symmetry modifying factor using finite element software prediction material under pressure head effect;(4) material uniaxial tensile test obtains elasticity modulus of materials and combines finite element software by GTN theory to obtain material critical hole ratio;(5) will be pressed into function be associated with energy to failure and with strain energy density equivalence, thus obtain by critical plasticity residual depth characterize fracture toughness equation.This fracture toughness test method can obtain the elasticity modulus and fracture toughness numerical value of material by the small-scale micro-indentation test of material, quick, low damage.

Description

A method of fracture toughness is calculated using indentation method
Technical field
The present invention relates to fracture toughness test technical fields, and in particular to a kind of side that fracture toughness is calculated using indentation method Method.
Background technique
With the continuous development of aeronautical engineering, reactor engineering, welding technique and petroleum works, to metal material mechanics The demand of performance test is growing.There are a large amount of in-service equipment, tradition in the industries such as thermoelectricity, nuclear power, metallurgy and petrochemical industry Sampling test can obtain the more comprehensive performance parameter of in-service equipment and materials, but sampling test generally has destruction, no Suitable for in-service equipment.Indentation method is not required to sample, and has lossless characteristic, and can accurately and reliably obtain the machine of in-service equipment and materials Tool performance.Indentation test device volume is relatively small, and the positioning of tested region is easily achieved when test, can be applied to survey The material (such as weld seam, heat affected area, base material) of scale face performance gradient change.It is disconnected using impression test in view of advantage above The method for splitting toughness test can quick, the lossless fracture toughness numerical value for obtaining material.
The test function of impression and energy phase needed for crackle crack initiation when impression crack initiation energy (IEF) model thinks to reach critical load Deng.When having the continuous ball impression test fracture toughness using IEF, because of the geometry of ball, need to be pressed into biggish depth, It can not be tested in certain functionally gradient material (FGM)s, knee;And Berkovich pressure head is larger in calculating decrement elasticity modulus error, it is existing Indentation method is simultaneously unreasonable, thus needs to improve.
Summary of the invention
For overcome the deficiencies in the prior art, the present invention provides it is a kind of using indentation method calculate fracture toughness method, Method by continuously adding unloading using Berkovich pressure head on indentation equipment to measured material, it is corresponding to obtain measured material Unloading point effective modulus of elasticity and plasticity residual depth according to the indentation function of foundation and energy to failure incidence formula, and then obtain material The fracture toughness of material, the process for obtaining the fracture toughness numerical value of material is quick, low damage, being capable of effectively save experimental material consumption Take.
The following technical solution is employed by the present invention:
A method of fracture toughness being calculated using indentation method, is included the following steps:
(1) it is based on indentation test, under constant rate of speed, obtains and is no less than whole load-displacement song under 6 unloading conditions Line;
(2) fitting of first power function parameter is carried out to the part each unloading curve 30%-70%, it is remaining after being unloaded It is plastically deformed depth hp, contact depth hcParameter calculates the unloading rigidity at every curve unloading;
It carries out a straight line fitting again to each unloading curve again, obtains the unloading rigidity of each curve;
The unloading rigidity cut-off line match value of first curve, Article 2 start the unloading rigidity for calculating power function fitting Value is compared with the value of straight line fitting, if the two error judges that power function fitting parameter is effective in 10%;
To effective data point P and hpIt is fitted using following equation:
Wherein, hpFor afterflow depth after unloading, P is loading of pressing in, C1、C2、C3For fitting parameter and meet C2* C3< 0, and then obtain hpWith the parameters relationship of P;
(3) pressure head process of press in is simulated using finite element, obtains radial displacement correction factor and Berkovich pressure head Non-axis symmetry modifying factor, to obtain decrement elasticity modulus;
(4) using finite element to process simulation is uniaxially stretched, the critical hole ratio of material is obtained;
(5) by the indentation function and indentation energy to failure incidence formula that propose, fracture toughness is calculated in conjunction with critical hole ratio;
The indentation function and indentation energy to failure incidence formula are as follows:
Wherein GIEFTo be pressed into energy to failure, F (hp) it is hpDepth is pushed down into function, P (hp) it is hpLoad under depth, Ap(hp) be hpImpression perspective plane area, calculating formula under depth are as follows:
Wherein, γ is radial displacement correction factor, hpFor unloading after afterflow depth,For critical residual plasticity Deforming depth;
In conjunction with the P and h obtained in step (2)pFitting formula, must be pressed into energy to failure aboutFunction are as follows:
Wherein A, B, C are respectively
Critical residual is plastically deformed depthPass throughWith lnhpRelationship acquires, relationship are as follows:
WhereinFor effective modulus of elasticity, K, b are fitting parameter;
Effective modulus of elasticityCalculation formula are as follows:
Wherein, υ is measured material Poisson's ratio, υiFor pressure head material Poisson's ratio, ErTo reduce elasticity modulus, EiFor pressure head bullet Property modulus;
InIn E when Critical fracture*Taking corresponding ordinate is critical residual plastic deformation depth
It is pressed into energy to failure and strain energy density is of equal value, equivalence formula are as follows:
Wherein ScrFor critical strain energy density, υ is measured material Poisson's ratio, and SED is strain energy density;
And haveThen fracture toughness finally solves formula are as follows:
Wherein KICFor fracture toughness, E is measured material elasticity modulus.
Preferably, indentation test using constant Berkovich pressure head continuously adds the method for unloading, pressure head in step (1) No less than 6 equal difference loads, and the unloading after having loaded each time are carried out with the loading speed of 50mN/s, obtain whole load- Displacement curve.
Preferably, power function parameter fitting formula in step (2) are as follows:
P=B (h-hp)m
Wherein, B, m are fitting parameter, hpFor afterflow depth after unloading, h is pressure head compression distance;
Straight Line Fitting Parameters relationship are as follows:
P=a+S2*h
Wherein, a is fitting parameter, S2For the unloading rigidity in Straight Line Fitting Parameters;
Unloading rigidity S in power function parameter1It is obtained by Oliver-Pharr method, is calculated and obtained by following formula,
S1=Bm (hmax-hp)m-1
Wherein, hmaxFor compression distance maximum in indentation test.
Preferably, reduce the calculation formula of elasticity modulus in step (3) are as follows:
Wherein, ErTo reduce elasticity modulus, β is Berkovich pressure head non-axis symmetry modifying factor, and γ repairs for radial displacement Positive coefficient, AcTo contact depth area, S is unloading rigidity, and S takes S at first unloading curve2, unloaded in each later Curve is using the unloading rigidity S in power function parameter1
The invention has the advantages that:
1, this indentation method calculating fracture toughness method can be by passing through Berkovich to measured material on indentation equipment Pressure head continuously adds the method for unloading, obtains measured material and corresponds to unloading point effective modulus of elasticity and plasticity residual depth, according to building The indentation rendered meritorious service and energy to failure incidence formula, and then can get the fracture toughness of material, can more rapidly, low damage obtain the disconnected of material Ductility values are split, effectively save experimental material expends.
2, the present invention optimizes the fit range of material unloading curve, and by match value and experiment value error analysis, Guarantee the validity of fitting data.
3, material critical plasticity residual depth is associated with by the present invention by critical hole ratio, and critical hole ratio is drawn by uniaxial It stretches reality to obtain in conjunction with finite element, avoids the human factor of traditional statistical acquisition, so as to more accurately predict that material is disconnected Split ductility values.
4, the initial indentation stage elasticity modulus accuracy obtained in calculating process of the present invention significantly improves, and answers with engineering With value.
Detailed description of the invention
Fig. 1 is the flow chart that indentation method calculates fracture toughness method;
Fig. 2 is that Berkovich pressure head is pressed into material schematic diagram;
Fig. 3 is pressure head radial displacement illustraton of model;
Fig. 4 is the micro-indentation test curve of Al6061 alloy;
Fig. 5 is the micro-indentation test curve of SS302 alloy.
Specific embodiment
The present invention is specifically described with reference to the accompanying drawing:
As shown in Figs. 1-2, a kind of indentation method calculates fracture toughness method, characterized by the following steps:
Step (1) is based on indentation test, under constant rate of speed, obtains and is no less than whole load-position under 6 unloading conditions Move curve;
Indentation test continuously adds the method for unloading using constant Berkovich pressure head, and pressure head is with the load speed of 50mN/s Rate carries out no less than 6 equal difference loads, and the unloading after having loaded each time, obtains whole load-displacement curves.
Step (2) carries out the fitting of first power function parameter to each unloading curve, obtains plasticity residual depth, contact Depth state parameter calculates and unloads rigidity at every curve unloading, then carries out a straight line fitting again to each unloading curve, The unloading rigidity of each curve is obtained, and obtains hpWith P parameters relationship;
Unloading curve 30%-70% partial fitting, power function parameter fitting formula are chosen in fit procedure are as follows:
P=B (h-hp)m (1)
Wherein, B, m are fitting parameter, hpFor afterflow depth after unloading;
Straight Line Fitting Parameters relationship are as follows:
P=a+S2*h (2)
Wherein, a is fitting parameter, S2For the unloading rigidity in Straight Line Fitting Parameters,
Rigidity S is unloaded in power function parameter1It is obtained by Oliver-Pharr method, is calculated and obtained by following formula,
S1=Bm (hmax-hp)m-1 (3)
Wherein, hmaxFor compression distance maximum in indentation test;The unloading rigidity cut-off line match value of first curve, the Two unloading rigidity values for starting to calculate power function fitting are compared with the value of straight line fitting, if the two error judges in 10% Power function fitting parameter is effective;
To effective data point P and hpIt is fitted using following equation:
Wherein, C1、C2、C3For fitting parameter and meet C2*C3< 0.
Step (3), using finite element to pressure head process of press in simulate, obtain radial displacement correction factor and Berkovich pressure head non-axis symmetry modifying factor, to obtain decrement elasticity modulus;
Pressure head radial displacement model is as shown in Figure 3
Wherein, apart from pressure head center line distance at r* initial markers point A*, r is after being pressed into since initial markers point is by A* It varies at A apart from pressure head center line distance.
Three-dimensional circular cone pressure head is utilized respectively for the solution of non-axis symmetry modifying factor and three-dimensional Berkovich pressure head is limited Meta-model simulates nanometer process of press in of the different materials under identical load depth, and calculates the contact stiffness and bullet of unloading curve Property modulus, wherein contact stiffness ratio obtained by contact stiffness obtained by three-dimensional Berkovich pressure head and three-dimensional circular cone pressure head is as repaired Positive divisor β.
Reduce elasticity modulus, calculation formula are as follows:
Wherein, ErTo reduce elasticity modulus, β is Berkovich pressure head non-axis symmetry modifying factor, and γ repairs for radial displacement Positive coefficient, S are that unloading rigidity (namely judge in effective power function parameter unloading rigidity S1), unloading rigidity S passes through Oliver- Pharr method obtains.
Step (4) obtains the critical hole ratio of material using finite element to process simulation is uniaxially stretched;
It is tough to calculate fracture in conjunction with critical hole ratio by the indentation function and indentation energy to failure incidence formula proposed for step (5) Property.
It is pressed into function and indentation energy to failure incidence formula is as follows:
Wherein GIEFTo be pressed into energy to failure, F (hp) it is hpDepth is pushed down into function, P (hp) it is hpLoad under depth, Ap(hp) be hpImpression perspective plane area, calculating formula under depth are as follows:
Wherein, γ is radial displacement correction factor, hpAfterflow depth after unloading,For the change of critical residual plasticity Shape depth.In conjunction with acquisition P (h in step (2)p) fitting formula, can must be pressed into energy to failure aboutFunction are as follows:
Wherein A, B, C are respectively
Critical residual is plastically deformed depthPass throughWith lnhpRelationship acquires, relationship are as follows:
WhereinFor effective modulus of elasticity, K, b are fitting parameter,
Effective modulus of elasticityCalculation formula are as follows:
Wherein, υ is measured material Poisson's ratio, υiFor pressure head material Poisson's ratio, EiFor pressure head elasticity modulus
InIn E when Critical fracture*Taking corresponding ordinate is critical residual plastic deformation depth
Damaging hole theory according to metal toughness has following formula:
Wherein, D is damage ratio,For effective modulus of elasticity, E is measured material elasticity modulus.
Wherein, f is the hole ratio of metal toughness damage,
Have in metal critical breaking state:
f*=fF (14)
Wherein, fFFor in step (4) by test and finite element optimization critical hole ratio
It is pressed into energy to failure and strain energy density is of equal value, equivalence formula are as follows:
Wherein ScrFor critical strain energy density, υ is material Poisson's ratio, and SED is strain energy density.
And have
Then fracture toughness finally solves formula are as follows:
Wherein KICFor fracture toughness, E is elasticity modulus of materials.
Calculate Al6061 alloy and SS302 alloy fracture toughness.Fig. 4 is the micro-indentation test curve of Al6061 alloy, Fig. 5 is the micro-indentation test curve of SS302 alloy.The parameter in model mentioned in the present invention is obtained by test data fitting, Each fitting parameter of Al6061, γ=1.1, β=1.049, f in fit procedure*=0.045, E*=58.3583GPa,GIEF=5.495mJ/m2, can be calculatedIt is obtained with routine experimentDeviation be 3% be less than current method 15%;Each fitting parameter of SS302 in fit procedure, γ= 1.02, β=1.034, f*=0.195, E*=109.195GPa,GIEF=5.750mJ/m2, can be calculatedIt is obtained with routine experimentDeviation be 3%, less than current method 15%, and can compared with conventional method more rapidly, lossless acquisition material fracture toughness data.
1 distinct methods of table, which calculate, obtains Al6061 alloy effective modulus of elasticity and elasticity modulus error analysis
2 distinct methods of table, which calculate, obtains SS302 alloy effective modulus of elasticity and elasticity modulus error analysis
During initial loading, material does not start to damage, and the effective modulus of elasticity after calculating should be with practical routine Mechanical test acquired value is close, with experiment progress due to damage generation, effective modulus of elasticity should further decline with Routine experiment acquired value, from table 1 in table 2 it can be seen that measure effective modulus of elasticity precision obviously high for original state in the present invention In the method for Sina Amiri, the method for the present invention can predict elastic modulus change development trend very well, therefore proposed by the present invention Method can rationally determine the Critical fracture state of material, obtain the not damaged elasticity modulus of material and Fracture Toughness.
3 distinct methods of table, which calculate, obtains fracture toughness error analysis
The result of table 3 reflects that fracture toughness computation model proposed by the invention can be reasonably under different materials Acquisition Fracture Toughness, therefore, fracture toughness test method proposed by the present invention can accurately calculate the elasticity modulus of material with Fracture Toughness.
Certainly, the above description is not a limitation of the present invention, and the present invention is also not limited to the example above, this technology neck The variations, modifications, additions or substitutions that the technical staff in domain is made within the essential scope of the present invention also should belong to of the invention Protection scope.

Claims (4)

1. a kind of method for calculating fracture toughness using indentation method, which comprises the steps of:
(1) it is based on indentation test, under constant rate of speed, obtains and is no less than whole load-displacement curves under 6 unloading conditions;
(2) fitting of first power function parameter, residual plastic after being unloaded are carried out to the part each unloading curve 30%-70% Deforming depth hp, contact depth hcParameter calculates the unloading rigidity at every curve unloading;
It carries out a straight line fitting again to each unloading curve again, obtains the unloading rigidity of each curve;
The unloading rigidity cut-off line match value of first curve, Article 2 start by power function fitting calculate unloading rigidity value with The value of straight line fitting compares, if the two error judges that power function fitting parameter is effective in 10%;
To effective data point P and hpIt is fitted using following equation:
Wherein, hpFor afterflow depth after unloading, P is loading of pressing in, C1、C2、C3For fitting parameter and meet C2*C3< 0, and then obtain hpWith the parameters relationship of P;
(3) pressure head process of press in is simulated using finite element, obtains radial displacement correction factor and the non-axis of Berkovich pressure head The symmetry correction factor, to obtain decrement elasticity modulus;
(4) using finite element to process simulation is uniaxially stretched, the critical hole ratio of material is obtained;
(5) by the indentation function and indentation energy to failure incidence formula that propose, fracture toughness is calculated in conjunction with critical hole ratio;
The indentation function and indentation energy to failure incidence formula are as follows:
Wherein GIEFTo be pressed into energy to failure, F (hp) it is hpDepth is pushed down into function, P (hp) it is hpLoad under depth, Ap(hp) it is hpDepth Lower impression perspective plane area, calculating formula are as follows:
Wherein, γ is radial displacement correction factor, hpFor unloading after afterflow depth,For critical residual plastic deformation Depth;
In conjunction with the P and h obtained in step (2)pFitting formula, must be pressed into energy to failure aboutFunction are as follows:
Wherein A, B, C are respectively
Critical residual is plastically deformed depthPass throughWith ln hpRelationship acquires, relationship are as follows:
WhereinFor effective modulus of elasticity, K, b are fitting parameter;
Effective modulus of elasticityCalculation formula are as follows:
Wherein, υ is measured material Poisson's ratio, υiFor pressure head material Poisson's ratio, ErTo reduce elasticity modulus, EiFor pressure head springform Amount;
InIn E when Critical fracture*Taking corresponding ordinate is critical residual plastic deformation depth
It is pressed into energy to failure and strain energy density is of equal value, equivalence formula are as follows:
Wherein ScrFor critical strain energy density, υ is measured material Poisson's ratio, and SED is strain energy density;
And haveThen fracture toughness finally solves formula are as follows:
Wherein KICFor fracture toughness, E is measured material elasticity modulus.
2. a kind of method for calculating fracture toughness using indentation method according to claim 1, which is characterized in that step (1) Middle indentation test continuously adds the method for unloading using constant Berkovich pressure head, and pressure head is carried out with the loading speed of 50mN/s No less than 6 equal difference loads, and the unloading after having loaded each time, obtain whole load-displacement curves.
3. a kind of method for calculating fracture toughness using indentation method according to claim 1, which is characterized in that step (2) Middle power function parameter fitting formula are as follows:
P=B (h-hp)m
Wherein, B, m are fitting parameter, hpFor afterflow depth after unloading, h is pressure head compression distance;
Straight Line Fitting Parameters relationship are as follows:
P=a+S2*h
Wherein, a is fitting parameter, S2For the unloading rigidity in Straight Line Fitting Parameters;
Unloading rigidity S in power function parameter1It is obtained by Oliver-Pharr method, is calculated and obtained by following formula,
S1=Bm (hmax-hp)m-1
Wherein, hmaxFor compression distance maximum in indentation test.
4. a kind of method for calculating fracture toughness using indentation method according to claim 3, which is characterized in that step (3) The calculation formula of middle decrement elasticity modulus are as follows:
Wherein, ErTo reduce elasticity modulus, β is Berkovich pressure head non-axis symmetry modifying factor, and γ is radial displacement amendment system Number, AcTo contact depth area, S is unloading rigidity, and S takes S at first unloading curve2, in each unloading curve later Using the unloading rigidity S in power function parameter1
CN201910249521.3A 2019-03-29 2019-03-29 A method of fracture toughness is calculated using indentation method Active CN109900554B (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN201910249521.3A CN109900554B (en) 2019-03-29 2019-03-29 A method of fracture toughness is calculated using indentation method
PCT/CN2019/081981 WO2020199235A1 (en) 2019-03-29 2019-04-10 Method for calculating fracture toughness using indentation method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910249521.3A CN109900554B (en) 2019-03-29 2019-03-29 A method of fracture toughness is calculated using indentation method

Publications (2)

Publication Number Publication Date
CN109900554A CN109900554A (en) 2019-06-18
CN109900554B true CN109900554B (en) 2019-11-08

Family

ID=66954200

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910249521.3A Active CN109900554B (en) 2019-03-29 2019-03-29 A method of fracture toughness is calculated using indentation method

Country Status (2)

Country Link
CN (1) CN109900554B (en)
WO (1) WO2020199235A1 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111257536A (en) * 2020-01-20 2020-06-09 中国科学院武汉岩土力学研究所 Rock mechanics and reservoir engineering parameter evaluation method
CN111351710A (en) * 2020-03-24 2020-06-30 中国电子科技集团公司第三十八研究所 Method for measuring Poisson's ratio of viscoelastic material
CN111964824B (en) * 2020-08-19 2021-11-09 中国石油大学(华东) Method for testing residual stress based on indentation energy difference
CN113466038B (en) * 2021-06-21 2022-05-20 长江存储科技有限责任公司 Detection sample for fracture toughness and detection method thereof
CN114935516A (en) * 2022-04-28 2022-08-23 中国石油大学(华东) Method for testing tensile property of metal material by adopting ball indentation method
CN115235888B (en) * 2022-07-06 2023-06-13 中国人民解放军国防科技大学 Material elastic property in-situ local touch pressure measurement method and measurement system
CN115931548B (en) * 2022-10-13 2023-07-18 荣梓华 Young modulus determining method and device and electronic equipment

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5602329A (en) * 1995-08-09 1997-02-11 Massachusetts Institute Of Technology Method and apparatus for measuring fracture toughness of a material
KR100302400B1 (en) * 1998-12-21 2001-11-02 이구택 Method for evaluating weldability of welded thick plate with ease
CN100501368C (en) * 2006-11-01 2009-06-17 北京科技大学 Apparatus for testing transformation temperature between toughness and brittleness, rupture toughness at different temperature and rigidity
CN103091185B (en) * 2011-10-31 2014-11-19 湘潭大学 Process for characterizing elastoplasticity of metal material through indentation method
CN103439206B (en) * 2013-09-13 2015-03-25 徐州工程学院 Micro-indentation-based method for testing residual stress of tiny area of tough block material
CN104122154B (en) * 2014-07-22 2017-01-18 中国人民解放军装甲兵工程学院 Method for testing ceramic material fracture toughness by means of instrumented Vickers indentation
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
CN107063905A (en) * 2017-03-29 2017-08-18 西南石油大学 A kind of shale fracture toughness computational methods based on scratch experiment
CN109253913B (en) * 2017-07-13 2020-11-03 中国石油天然气集团公司 Device and method for measuring dynamic fracture toughness of material

Also Published As

Publication number Publication date
WO2020199235A1 (en) 2020-10-08
CN109900554A (en) 2019-06-18

Similar Documents

Publication Publication Date Title
CN109900554B (en) A method of fracture toughness is calculated using indentation method
CN110296892B (en) Method for determining characteristic stress in rock damage evolution process based on energy analysis
Zhu et al. Strain energy gradient-based LCF life prediction of turbine discs using critical distance concept
Kamal et al. Advances in fatigue life modeling: A review
CN103886125B (en) A kind of titanium alloy hot combined shaping method for numerical simulation
CN106934168B (en) A kind of material multi-axial creep failure strain prediction technique
CN111189699A (en) Method for realizing parameter inversion identification of crystal plastic material based on nanoindentation experiment
CN106248502A (en) The method that cantilever beam bending obtains material elastic plastic mechanical properties
Gallo et al. Analysis of creep stresses and strains around sharp and blunt V-notches
CN104165814B (en) Vickers indentation based material elastoplasticity instrumented indentation test method
CN108387470A (en) A kind of method of continuous indentation method measurement remnant stress and metal material elastic plastic mechanical properties
Torres et al. Mechanics of the small punch test: a review and qualification of additive manufacturing materials
CN110987676A (en) Full-life prediction method considering crack closure effect under random multi-axis load
Dyson et al. Use of small specimen creep data in component life management: a review
CN103217282A (en) Fatigue test method of blade scaling model of horizontal axis wind turbine based on equal-service-life principle
CN108763839A (en) A kind of centrifugal impeller boss crack propagation characteristic simulation part design method
US20240012958A1 (en) Approach for characterizing propagation of metallic short cracks and long cracks
US10712316B2 (en) Fixed value residual stress test block and manufacturing and preservation method thereof
CN108844824A (en) A kind of known materials residual stress analysis method based on conical pressure head
CN107220410A (en) Parameter is on welding residual stress and deformation influence susceptibility acquisition methods
CN104655505A (en) Instrumented-ball-pressing-technology-based residual stress detection method
Wang et al. Ductile tearing analyses of cracked TP304 pipes using the multiaxial fracture strain energy model and the Gurson–Tvergaard–Needleman model
CN104237037B (en) Material elastoplasticity parameter instrumented indentation testing method based on Berkovich indentation
Jin et al. Analysis of mixed-mode Compact-Tension-Shear (CTS) specimens with slanted propagating cracks
CN109490334B (en) Nondestructive testing method for T-shaped forge piece by using residual stress prediction model

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
TR01 Transfer of patent right

Effective date of registration: 20230420

Address after: Luo she Zhen Dou men Cun, Huishan District, Wuxi City, Jiangsu Province, 214000

Patentee after: Jiangsu Jiayian Technology Co.,Ltd.

Address before: 266580 No. 66 Changjiang West Road, Huangdao economic and Technological Development Zone, Qingdao, Shandong

Patentee before: CHINA University OF PETROLEUM (EAST CHINA)

TR01 Transfer of patent right