CN106777484A - A kind of computational methods of surface crack growth shape - Google Patents

A kind of computational methods of surface crack growth shape Download PDF

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Publication number
CN106777484A
CN106777484A CN201611024353.0A CN201611024353A CN106777484A CN 106777484 A CN106777484 A CN 106777484A CN 201611024353 A CN201611024353 A CN 201611024353A CN 106777484 A CN106777484 A CN 106777484A
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crack
computational methods
release rate
energy release
surface crack
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贺利乐
王兴路
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Xian University of Architecture and Technology
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Xian University of Architecture and Technology
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    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
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    • G06F30/17—Mechanical parametric or variational design

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Abstract

The invention discloses a kind of computational methods of surface crack growth shape, its step includes：Determine that material or planform influence coefficient to cracks stress intensity factor；The stress intensity factor of difference gauging surface crack surfaces point and cusp；The energy release rate of difference gauging surface crack surfaces point and cusp；Calculate effective energy release rate；Functional relation is set up based on energy release rate theory；The relation of face crack form parameter a and c is solved, the change in shape during surface crack growth is determined.The computational methods of surface crack growth shape of the present invention propose a kind of surface crack growth shape computational methods from point of theory, and technical support is provided to material containing face crack and Structural Damage Assessment.

Description

A kind of computational methods of surface crack growth shape
Technical field
The present invention relates to a kind of shape computational methods, a kind of particularly computational methods of surface crack growth shape.
Background technology
Due to the influence of processing factors, tiny area crackle is easily formed in material or body structure surface, in engineering structure often Caused by the penetrated crack phenomenon of rupture of appearance is mainly and gradually extended by initial tiny area crackle, in material or structure Under external applied load continuous action, face crack will forward extend face crack in semiellipse shape, the serious shadow of appearance of face crack Ring the working strength and service life of military service material and structure.Face crack is hidden in material or inside configuration, using current Detection means can obtain the crack length of material or structural outer surface, obtained for inside crack form and dimension and be relatively stranded It is difficult.At present to being based on experimental data and experience surface crack growth Shape Prediction, lacking the support of theory more.
The content of the invention
In view of the foregoing defects the prior art has, the technical problem to be solved in the present invention is to analyze complicated from point of theory A kind of surface crack growth of structure, there is provided computational methods of surface crack growth shape.
In order to solve the above technical problems, the invention provides a kind of computational methods of surface crack growth shape, it includes Following steps：
S1, determines that material or planform influence coefficient to cracks stress intensity factor；
The stress intensity factor of S2, difference gauging surface crack surfaces point and cusp；
The energy release rate of S3, difference gauging surface crack surfaces point and cusp；
S4, calculates effective energy release rate；
S5, functional relation is set up based on energy release rate theory；
S6, solves the relation of face crack form parameter a and c, determines the change in shape during surface crack growth.
Preferably, in the step S1, determining material or planform to gauging surface stress intensity factor of crack Influence coefficient MKDetermined by the structure type of face crack position.
Preferably, in the step S2, the stress of difference gauging surface crackle upper table millet cake (C points) and cusp (A points) Intensity factor KCAnd KA, wherein, in calculating stress strength factor KCAnd KAThe following formula of Shi Caiyong：External applied load is produced in cracks I type stress intensity factors be：In formula：σtIt is tensile stress, σbFor Bending stress, a/c is crackle aspect ratio, and a/B is crack depth ratio, and W is that plate is wide,It is face crack parameter angle,Φ is integrated for semiellipse,
Preferably, describedCalculation be：
In formula：
Preferably, in the step S3, difference gauging surface crackle upper table millet cake (C points)
With the energy release rate G of cusp (A points)AAnd GC；Wherein,In formula,
E is elasticity modulus of materials, and υ is Poisson's ratio.
Preferably, in the step S4, it is considered to the crack closure influence in crack propagation process, difference computational chart facial cleft The effective energy release rate G of line upper table millet cake (C points) and cusp (A points)AeffAnd GCeff；
In formula, U represents the influence of crack closure effect in crack propagation process, opening at semiellipse crack surfaces point C Than with cusp A at open and be approximately 0.9 than ratio, therefore, take U in Research on surface crack calculating processC/UA=0.9.
Preferably, in the step S5, it is theoretical based on energy release rate, it is assumed that to be released along energy at each point on face crack Put rate equal, set up face crack upper table millet cake (C points) with cusp (A points) place energy release rate relation GAeff=GCeff。
Preferably, in the step S6, surface half-ellipse crack parameter a and c are solved according to the functional relation set up Relation, you can determine the change in shape during surface crack growth.
The computational methods of surface crack growth shape of the present invention propose a kind of surface crack growth from point of theory Shape computational methods, technical support is provided to material and Structural Damage Assessment.
Brief description of the drawings
Fig. 1 is the schematic diagram of the flat board being related in embodiments of the invention；
The step of Fig. 2 is the computational methods of surface crack growth shape of the present invention schematic diagram；
Fig. 3 is the effect diagram of the computational methods of surface crack growth shape of the present invention；
Fig. 4 is the effect diagram of the computational methods of surface crack growth shape of the present invention.
Specific embodiment
The present invention is described in further detail with specific embodiment below in conjunction with the accompanying drawings, but not as to limit of the invention It is fixed.
Fig. 1 shows the example of the slab construction that there is face crack, wherein, the thickness of slab construction is B, plate W wide, such as Shown in Fig. 1, the face crack existed in slab construction is in half-oval shaped, and the depth of face crack is a, the surface of face crack Length is 2c, wherein, the deepest point of face crack is referred to as cusp, is designated as A points, and face crack surface point is designated as C points.Slab construction In the presence of external applied load, its face crack is in half elliptic and gradually extends, but its ratio of semi-minor axis length can be with crack depth Change and change, surface crack growth shape computational methods of the present invention are exactly theoretically to set up semiellipse surface to split The relation of line form parameter a and c, by detecting crack surfaces length 2c, it is possible to face crack depth a is determined, to be damaged Wound assessment provides foundation.
As shown in Fig. 2 Fig. 2 shows the circular of surface crack growth shape, it is comprised the following steps：
S1, determines that material or planform influence coefficient to cracks stress intensity factor；
The stress intensity factor of S2, difference gauging surface crack surfaces point and cusp；
S3, difference gauging surface crack surfaces point and cusp volume energy release rate；
S4, calculates effective energy release rate；
S5, functional relation is set up based on energy release rate theory；
S6, solves the relation of face crack form parameter a and c, determines the change in shape during surface crack growth.
The particular content of above steps will be described in detail below, wherein,
For S1, the influence coefficient M of material or planform to gauging surface stress intensity factor of crack is determinedK；MKBy table The structure type of facial cleft line position determines, for the face crack M in flat boardK=1.
For S2, the stress strength factor K of difference gauging surface crackle upper table millet cake (C points) and cusp (A points)CAnd KA, its In, in calculating stress strength factor KCAnd KAThe following formula of Shi Caiyong：The I type stress intensity factors that external applied load is produced in cracks For：In formula：σtIt is the tensile stress of institute's point position, σbIt is institute's measuring point The bending stress of position, a/c is crackle aspect ratio, and a/B is crack depth ratio, and W is that plate is wide,It is face crack parameter angle,Φ is integrated for semiellipse,
In formula：
For S3, the energy release rate G of difference gauging surface crackle upper table millet cake (C points) and cusp (A points)AAnd GC；Its In,In formula,E is elasticity modulus of materials, and υ is Poisson's ratio.
For S4, it is considered to the crack closure influence in crack propagation process, difference gauging surface crackle upper table millet cake (C points) With the effective energy release rate G of cusp (A points)AeffAnd GCeff；
In formula, U represents the influence of crack closure effect in crack propagation process, at semiellipse crack surfaces point C Open than with cusp A at open and be approximately 0.9 than ratio, therefore, take U in Research on surface crack calculating processC/UA=0.9；
It is theoretical based on energy release rate, it is assumed that equal along energy release rate at each point on face crack for S5, set up table Facial cleft line upper table millet cake (C points) and cusp (A points) place energy release rate relation GAeff=GCeff；
Surface half-ellipse crack parameter a and c relations are solved according to the functional relation set up for S6, you can determine surface Change in shape in crack propagation process.
In a detailed embodiment, the specific plate with face crack is chosen to be used to describe face crack expansion in detail The implementation result of the computational methods of spread shape, wherein, the structural parameters of flat board are as follows：Thick 20mm, 60mm wide, material is Q345, Surface crack growth change in shape of the flat board under tensile load effect, by above-mentioned computational methods, result of calculation and implementation are imitated Fruit as shown in Figures 3 and 4, wherein, Fig. 4 be flat board under stretching action, its surface crack growth schematic shapes.Specifically, table Facial cleft line keeps semiellipse shape to extend forward in expansion process, due to the influence of material and structural parameters, in its expansion process Middle half-oval shaped can change, i.e., the ratio between semi-major axis of semiellipse can change, and affect to the damage containing defective material Wound assessment.This computational methods can be based on theoretical functional relation of the foundation comprising crack shape parameter of energy release rate, pass through Solution obtains surface half-ellipse crack form parameter change in crack propagation process, is to carry out damage to structure containing face crack to comment Offer technical support is provided.
Certainly, the above is the preferred embodiment of the present invention, it is noted that for the ordinary skill of the art For personnel, under the premise without departing from the principles of the invention, some improvements and modifications can also be made, these improvements and modifications It is considered as protection scope of the present invention.

Claims (8)

1. a kind of computational methods of surface crack growth shape, it is comprised the following steps：
S1, determines that material or planform influence coefficient to cracks stress intensity factor；
The stress intensity factor of S2, difference gauging surface crack surfaces point and cusp；
The energy release rate of S3, difference gauging surface crack surfaces point and cusp；
S4, calculates effective energy release rate；
S5, functional relation is set up based on energy release rate theory；
S6, solves the relation of face crack form parameter a and c, determines the change in shape during surface crack growth.
2. computational methods of surface crack growth shape according to claim 1, it is characterised in that in the step S1, Determine the influence coefficient M of material or planform to gauging surface stress intensity factor of crackK, the MKBy where face crack The structure type of position determines.
3. computational methods of surface crack growth shape according to claim 2, it is characterised in that the step S2 In, the stress strength factor K of difference gauging surface crackle upper table millet cake (C points) and cusp (A points)CAnd KA, wherein, in meter Calculate stress strength factor KCAnd KAThe following formula of Shi Caiyong：External applied load is in the I type stress intensity factors that cracks are produced：In formula：σtIt is tensile stress, σbIt is bending stress, a/c is vertical for crackle Horizontal ratio, a/B is crack depth ratio, and W is that plate is wide,It is face crack parameter angle,Φ is integrated for semiellipse, Wherein,
H 1 = 1 - 0.34 ( a B ) - 0.11 ( a c ) · ( a B )
H 2 = 1 + G 1 ( a B ) + G 2 ( a B ) 2
G 1 = - 1.22 - 0.12 ( a c )
G 2 = - 0.55 - 1.05 ( a c ) 0.75 + 0.47 ( a c ) 1.5
p = 0.2 + a c + 0.6 a B .
4. computational methods of surface crack growth shape according to claim 3, it is characterised in that describedCalculation be：
In formula：
M 2 = - 0.54 + 0.89 0.2 + a / c
M 2 = 0.5 - 1 0.65 + a / c + 14 ( 1 - a / c ) 24
f w = [ S e c ( π 2 · 2 c W · a B ) ] 1 2 .
5. computational methods of surface crack growth shape according to claim 4, it is characterised in that in the step S3, The energy release rate G of difference gauging surface crackle upper table millet cake (C points) and cusp (A points)AAnd GC；Wherein,Formula In,
E is elasticity modulus of materials, and υ is Poisson's ratio.
6. computational methods of surface crack growth shape according to claim 5, it is characterised in that in the step S4, Consider the crack closure influence in crack propagation process, difference gauging surface crackle upper table millet cake (C points) has with cusp (A points) Effect energy release rate GAeffAnd GCeff；
G e f f = K I e f f 2 E ′ = ( UK I ) 2 E
In formula, U represents the influence of crack closure effect in crack propagation process, at semiellipse crack surfaces point C open than with Opening at cusp A is approximately 0.9 than ratio, therefore, take U in Research on surface crack calculating processC/UA=0.9.
7. computational methods of surface crack growth shape according to claim 6, it is characterised in that in the step S5, It is theoretical based on energy release rate, it is assumed that equal along energy release rate at each point on face crack, set up face crack upper table millet cake (C points) and cusp (A points) place energy release rate relation GAeff=GCeff。
8. computational methods of surface crack growth shape according to claim 7, it is characterised in that in the step S6, Surface half-ellipse crack parameter a and c relations are solved according to the functional relation set up, you can during determining surface crack growth Change in shape.
CN201611024353.0A 2016-11-18 2016-11-18 A kind of computational methods of surface crack growth shape Pending CN106777484A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109540057A (en) * 2018-11-16 2019-03-29 上海发电设备成套设计研究院有限责任公司 A kind of system and method that steam turbine high-temperature pressure-containing member defect is evaluated online
CN112733398A (en) * 2020-12-29 2021-04-30 南京航空航天大学 Method for determining repair-free limit of impact damage of pit-type hard object
CN113176142A (en) * 2021-03-11 2021-07-27 合肥通用机械研究院有限公司 Method for calculating axial-radial crack stress intensity factor of outer wall of ultrahigh pressure container barrel
WO2022059238A1 (en) * 2020-09-16 2022-03-24 Mitsubishi Electric Corporation Estimation device and estimation method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103339396A (en) * 2010-11-25 2013-10-02 Skf公司 Bearing and method of inhibiting crack propagation in a bearing component
CN103308381B (en) * 2013-06-07 2014-10-01 合肥通用机械研究院 Fatigue crack propagation rate normalization prediction method
CN104451662A (en) * 2014-11-21 2015-03-25 南京机电职业技术学院 Combined treatment method for crack repair and strengthening of part in high-temperature working environment

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103339396A (en) * 2010-11-25 2013-10-02 Skf公司 Bearing and method of inhibiting crack propagation in a bearing component
CN103308381B (en) * 2013-06-07 2014-10-01 合肥通用机械研究院 Fatigue crack propagation rate normalization prediction method
CN104451662A (en) * 2014-11-21 2015-03-25 南京机电职业技术学院 Combined treatment method for crack repair and strengthening of part in high-temperature working environment

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
NEWMAN JC,RAJU IS.: "An empirical stress-intensity factor equation for the surfacecrack", 《ENGINEERING FRACTURE MECHANICS》 *
张茉莉 等: "悬臂弯曲加载表面裂纹扩展长度与深度的关系研究", 《材料开发与应用》 *
涂周杰: "表面裂纹疲劳扩展和应力强度因子研究", 《中国优秀硕士学位论文全文数据库 基础科学辑》 *
温建锋: "基于应变的损伤力学模型及其在蠕变裂纹扩展数值模拟中的应用", 《中国博士学位论文全文数据库 基础科学辑》 *
王兴路: "焊接结构件疲劳分析方法及在塔机起重臂上的应用研究", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》 *
高潮 等: "基于能量模型的三维穿透裂纹扩展研究", 《航空动力学报》 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109540057A (en) * 2018-11-16 2019-03-29 上海发电设备成套设计研究院有限责任公司 A kind of system and method that steam turbine high-temperature pressure-containing member defect is evaluated online
WO2022059238A1 (en) * 2020-09-16 2022-03-24 Mitsubishi Electric Corporation Estimation device and estimation method
US11428612B2 (en) 2020-09-16 2022-08-30 Mitsubishi Electric Corporation Estimation device and estimation method
CN112733398A (en) * 2020-12-29 2021-04-30 南京航空航天大学 Method for determining repair-free limit of impact damage of pit-type hard object
CN113176142A (en) * 2021-03-11 2021-07-27 合肥通用机械研究院有限公司 Method for calculating axial-radial crack stress intensity factor of outer wall of ultrahigh pressure container barrel

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Application publication date: 20170531