CN108363859B - A kind of overall evaluation method to the atmospheric storage tank containing defect - Google Patents
A kind of overall evaluation method to the atmospheric storage tank containing defect Download PDFInfo
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Abstract
The invention discloses a kind of overall evaluation methods to the atmospheric storage tank containing defect, which comprises the following steps: property, size and the position of defect on measurement storage tank；According to tank structure and defective locations, size, property, the storage tank model of defect is established in Ansys software；Using Ansys software, loads real load and calculate tank structure intensity and storage tank stress intensity factor, load specific loading carries out stable calculation；The tank structure intensity, storage tank stress intensity factor and stability result that are calculated are evaluated, the safe condition of storage tank is fully assessed.The present invention solves the deficiency and missing in terms of current state's inner storage tank Safety Assessment Standard, the method for combining finite element soft Ansys to calculate by non-destructive testing early period detection, the safe condition of storage tank is had evaluated from multi-angles such as structural mechanics, fracture mechanicses, calculated result has higher reliability.
Description
Technical field
The present invention relates to petrochemical equipment technical fields, and in particular to a kind of entirety to the atmospheric storage tank containing defect is commented
Valence method.
Background technique
It is later that the storage tank in China examines work to carry out, and not yet forms the storage tank test stone of complete set at present.China exists
Large quantities of Petroleum Storage Tanks are built up the 80s and 90s, due to the missing of statutory standard at that time, the construction quality of many storage tanks is all
Ideal not to the utmost, inside is usually all haveed the defects that more.Currently, the domestic safety evaluation side for not being exclusively used in storage tank defect
Method, to storage tank defect carry out qualitative, quantitative if, generally can using RT (ray) flaw detection with PT (magnetic powder) flaw detection or
The method that MT (infiltration) flaw detection combines, fault grading is referring to NB/T47013 " bearing device non-destructive testing ", but this method has
It is following insufficient:
NB/T47013 " bearing device non-destructive testing " only discusses the method and technique of defect detection means, not to scarce
Sunken local pressure situation is calculated, but defect is defined the level according to flaw size, even but RT detects IV grade
II grade of defect of defect or PT, MT might not also will affect storage tank use.NB/T47013 " the lossless inspection of bearing device simultaneously
Survey " object of fault grading is bearing device, not fully it is suitable for storage tank.Storage tank according to the difference of construction quality, or it is more or
Few can all have the defects that at several places or tens, in this case, if all defect is all regarded as unqualified, repair
Science and engineering is made can be troublesome, greatly influences the production of enterprise, meanwhile, in mending course, once defects count is more, then may
Due to welding procedure, welder is horizontal, welding residual stress such as interacts at a variety of causes between the defect of many places, and storage tank is caused to be repaired
Effect is often not fully up to expectations afterwards.
Summary of the invention
In view of the defects and deficiencies of the prior art, the present invention intends to provide a kind of based on finite element modelling to containing
The overall evaluation method of the atmospheric storage tank of defect, to solve the problems, such as proposed in background technique.
To achieve the above object, the technical solution adopted by the present invention is that: a kind of entirety to the atmospheric storage tank containing defect is commented
Valence method, which is characterized in that property, size and the position of defect on detection storage tank；According to tank structure and defective locations, ruler
Very little, property establishes the storage tank model of defect in Ansys software；Using Ansys software, loads real load and calculate storage tank knot
Structure intensity and storage tank stress intensity factor, load specific loading carry out stable calculation；To the tank structure intensity being calculated,
Storage tank stress intensity factor and stability result are evaluated, and the safe condition of storage tank is fully assessed.
Further, a kind of overall evaluation method to the atmospheric storage tank containing defect, specifically includes the following steps:
S1. the property of defect, size and position on storage tank are detected using nondestructive means；
S2. use finite element analysis Ansys software, in Ansys, according to the position of the structure of storage tank and defect, size,
Property establishes the storage tank model containing defect according to 1:1 equal proportion；
S3. Ansys software is used, real load is loaded, calculates tank structure intensity, the real load is according to storage tank sheet
The situation and storage tank local environment of body calculate, and the calculating of the tank structure intensity is answered including maximum primary stress, maximum secondary
Power, maximum primary plus secondary stress, maximum total stress calculating, and the maximum in calculated tank structure intensity is once answered
Power, maximum secondary stress, maximum primary plus secondary stress, maximum total stress and national standard " JB/T4732-2005 steel pressure
Container-analysis design standard " compared one by one, if there is more than one not meet standard requirements, need to take integral reinforcing
Storage tank or the defect for repairing stress higher position；
S4. when containing crackle or incomplete fusion in defect type, Ansys software need to be used to calculate storage tank under real load
The point stresses intensity factor of crackle or incomplete fusion, by the point stresses intensity factor of crackle in storage tank or incomplete fusion and the storage
The fracture toughness of the used material of tank is compared；If the stress intensity factor of storage tank is less than fracture toughness, crackle and unmelted
Conjunction can't extend under current working；If it is greater than or equal to fracture toughness, then crackle and incomplete fusion have under current working
A possibility that extending need to repair in time, eliminate extension hidden danger；
S5. Ansys software is used, load specific loading carries out stable calculation, tank material buckling analysis is calculated
Characteristic value, that is, storage tank unstability do not occur can bear maximum load；It is loaded if characteristic value is greater than obtained in Strength Calculation
Maximum total stress under real load mode, then unstability does not occur for storage tank, if characteristic value is less than obtained in Strength Calculation
The maximum total stress under real load mode is loaded, then unstability has occurred for storage tank, then needs to eliminate all defect of unstable position
Or integral reinforcing is carried out to storage tank；
S6. when the result being calculated in step S3, S4 and S5, which is able to satisfy, to be required, then show the current work of the storage tank
It does not need to place under repair under condition, Daily Round Check can be reinforced by shortening round of visits, regular non-destructive testing guarantees the peace of storage tank
Quan Xing；If more than one calculated result is unsatisfactory for requiring, need corresponding according to the calculated result selection for being unsatisfactory for requiring
Treatment measures simultaneously calculate storage tank after processing again, with verification processing effect.
Wherein, the material of the storage tank uses linear elastic materials.
Wherein, nondestructive means in the step S1 select radiographic inspection with magnetic powder inspection in conjunction with, radiographic inspection and
One of penetrant inspection combination.
Wherein, in the step S3 load real load calculate tank structure intensity, specifically includes the following steps: a. according to
Medium, material, structure and the max reassembly amount of storage tank apply maximum level load to storage tank and from heavy load；B. inquiry is local
Highest wind velocity and it is on the books since highest earthquake intensity, load maximum wind velocity load and maximum seismic (seismal；C. pass through load step
Maximum level load in rapid a and step b, from heavy load, maximum wind velocity load and maximum seismic (seismal, calculate the storage tank
The stress distribution suffered by local most extreme environment, the stress distribution include maximum primary stress, maximum secondary stress, most
It is big once to add secondary stress and maximum total stress.
Wherein, in the step S4 load real load calculate storage tank in the point stresses intensity of crackle or incomplete fusion because
Son, specifically includes the following steps: in Ansys software, establishing stress-strain field according to linear elastic fracture mechanics theory；It uses
Ansys software calculating stress strength factor；When establishing stress-strain field, firstly, being drawn for crackle or incomplete fusion on storage tank
The line of the open bottom of crackle or incomplete fusion；Secondly, defining the office at description crackle or incomplete fusion tip first using KACLC order
Portion's coordinate system；Again, definition is along the path of crack surface；Finally, it is strong to calculate defect or the point stresses of incomplete fusion position in storage tank
Spend the factor；Wherein, in Ansys software calculating stress strength factor, needing manual designated analysis type is plane stress or plane
One of strain, the calculating for storage tank stress intensity factor select plane stress.
Wherein, in the step S5, load specific loading carries out stable calculation, according to Plate Theory, linear elasticity shell
Section very little between the balance and unstability of component, when linear elasticity hin shell member balance, material is in elastic deformation；When
When linear elasticity hin shell member unstability, material enters surrender；Storage tank load specific loading stable calculation needs bending based on material
Clothes are calculated；Stable calculation is specifically includes the following steps: (1) loads the face regional location one with actual loading on storage tank
The specific loading of cause, while applying identical constraint condition；(2) in Ansys software, the eigenvalue buckling in software point is used
Characteristic value is calculated in analysis；(3) by the characteristic value being calculated multiplied by the specific loading of application, when obtaining storage tank unstability not occurring
The maximum load that can bear, since loaded load is unit load, obtained characteristic value is storage tank in step (2)
The maximum load that can bear when unstability does not occur；(4) it can bear when unstability not being occurred for storage tank obtained in step (3)
Obtained load real load mould in Strength Calculation in characteristic value and the S1 step in maximum load, that is, step (2)
Maximum total stress under formula is compared analysis；If characteristic value is greater than maximum total stress obtained in Strength Calculation, store up
Unstability does not occur for tank；Conversely, storage tank unstability.
After adopting the above structure, the invention has the following beneficial effects: the present invention has filled up the storage tank flaw evaluation side of the current country
The blank of method proposes a kind of storage tank flaw evaluation system based on finite element modelling, is calculated and is stored up by finite element soft Ansys
The structural strength and stability of tank analyze the point stresses intensity factor of crackle and incomplete fusion, prevent crack propagation；Meanwhile
The two kinds of failure modes of strength failure and unstability for considering storage tank, can more all-sidedly and accurately evaluate the safe condition of storage tank.This hair
Deficiency and missing in terms of the bright current state's inner storage tank Safety Assessment Standard of solution, by non-destructive testing early period detection in conjunction with software meter
The method of calculation, the safe condition of storage tank is had evaluated from multi-angles such as structural mechanics, fracture mechanicses, and calculated result has higher reliable
Property.
Detailed description of the invention
Fig. 1 is the flow chart of overall evaluation method of the invention；
Fig. 2 is the stress result figure after the storage tank Ansys simulation of embodiment one in the present invention；
Fig. 3 is the stress result figure after the storage tank Ansys simulation of embodiment two in the present invention；
Fig. 4 is the stress result figure after the storage tank Ansys simulation of embodiment three in the present invention；
Fig. 5 is the stress result figure after the storage tank Ansys simulation of example IV in the present invention；
Fig. 6 is the stress result figure after the storage tank Ansys simulation of embodiment five in the present invention；
Fig. 7 is the stress result figure after the storage tank Ansys simulation of embodiment six in the present invention；
Fig. 8 is the stress result figure after the storage tank Ansys simulation of embodiment seven in the present invention；
Fig. 9 is the stress result figure after the storage tank Ansys simulation of embodiment eight in the present invention；
Specific embodiment
The present invention will be further described below with reference to the drawings.
In order to make the objectives, technical solutions, and advantages of the present invention clearer, below in conjunction with attached drawing and specific implementation
Mode, the present invention will be described in further detail.It should be appreciated that the specific embodiments described herein are only to explain this
Invention, is not intended to limit the present invention.
As shown in Figure 1, a kind of overall evaluation method to the atmospheric storage tank containing defect, wherein the material of the storage tank is adopted
Use linear elastic materials；Specifically includes the following steps:
S1. the property of defect, size and position on storage tank are detected using nondestructive means；Wherein, the lossless spy
Hurt method selection radiographic inspection in conjunction with magnetic powder inspection, radiographic inspection is one of in conjunction with penetrant inspection.
S2. finite element analysis Ansys software is used, in Ansys, according to the position of tank structure and defect, size, property
Matter establishes the storage tank model containing defect according to 1:1 equal proportion.
S3. Ansys software is used, load real load calculates tank structure intensity, the calculating of the tank structure intensity
Including maximum primary stress, maximum secondary stress, maximum primary plus secondary stress, maximum total stress calculating, and will calculate
Tank structure intensity in maximum primary stress, maximum secondary stress, it is maximum once plus secondary stress, maximum total stress and state
Family's standard " JB/T4732-2005 steel pressure vessel-analysis design standard " is compared one by one, if there is more than one not meet
Requirements of the national standard then needs to take integral reinforcing storage tank or repair the defect of stress higher position；Wherein, the load is practical
LOAD FOR tank structure intensity, specifically includes the following steps: a. is according to the medium of storage tank, material, structure and maximum filling weight,
Maximum level load is applied to storage tank and from heavy load；B. inquire local highest wind velocity and it is on the books since highest earthquake intensity,
Load maximum wind velocity load and maximum seismic (seismal；C. pass through the maximum level load in load step a and step b, heavy duty certainly
Lotus, maximum wind velocity load and maximum seismic (seismal calculate storage tank stress distribution suffered by local most extreme environment,
The stress distribution includes maximum primary stress, maximum secondary stress, maximum primary plus secondary stress and maximum total stress.Due to
Country, which there is no, at present formulates professional standard about storage tank, and storage tank and pressure vessel in structure and in use condition in the presence of compared with
More similitudes, therefore this programme is referring to " steel pressure vessel-analysis design standard "
S4. Ansys software is used, load real load calculates the point stresses intensity of crackle or incomplete fusion position in storage tank
The factor, point stresses intensity factor and the fracture of the used material of the storage tank that crackle or incomplete fusion position are lacked in storage tank is tough
Property is compared；If the stress intensity factor of storage tank is less than the defect of fracture toughness, crackle and incomplete fusion under current working
It can't extend；If it is greater than or equal to fracture toughness, then crackle and incomplete fusion have the possibility extended under current working
Property, it need to repair in time, eliminate the defect of extension hidden danger；Wherein, the load real load calculates crackle or incomplete fusion in storage tank
Point stresses intensity factor, specifically includes the following steps: according to linear elastic fracture mechanics theory, in Ansys software, establish
Stress-strain field；Use Ansys software calculating stress strength factor；When establishing stress-strain field, firstly, for splitting on storage tank
Line or incomplete fusion draw the line of the open bottom of crackle or incomplete fusion, secondly, defining description crackle first using KACLC order
Or the local coordinate system at incomplete fusion tip is defined along the path of crack surface again；Finally, calculating defect or incomplete fusion in storage tank
The point stresses intensity factor of position；Wherein, in Ansys software calculating stress strength factor, manual designated analysis type is needed
For one of plane stress or plane strain, the calculating for storage tank stress intensity factor selects plane stress.
S5. Ansys software is used, load specific loading carries out stable calculation, tank material buckling analysis is calculated
Characteristic value, that is, storage tank unstability do not occur can bear maximum load；It is loaded if characteristic value is greater than obtained in Strength Calculation
Maximum total stress under real load mode, then unstability does not occur for storage tank, if characteristic value is less than obtained in Strength Calculation
The maximum total stress under real load mode is loaded, then unstability has occurred for storage tank, then needs to eliminate all defect of unstable position
Or integral reinforcing is carried out to storage tank；Wherein, load specific loading carries out stable calculation, and according to Plate Theory, linear elasticity is thin
Section very little between the balance and unstability of mould component, when linear elasticity hin shell member balance, material is in elastic deformation；
When linear elasticity hin shell member unstability, material enters surrender；Storage tank load specific loading stable calculation is needed based on material
Surrender is calculated；Stable calculation is specifically includes the following steps: (1) loads the face regional location with actual loading on storage tank
Consistent specific loading, while applying identical constraint condition；(2) in Ansys software, the eigenvalue buckling in software is used
Analytical calculation obtains characteristic value；(3) characteristic value being calculated is obtained storage tank and unstability does not occur multiplied by the specific loading of application
When the maximum load that can bear, since loaded load is unit load, obtained characteristic value is storage in step (2)
The maximum load that can bear when unstability does not occur for tank；(4) it can bear when unstability not being occurred for storage tank obtained in step (3)
Maximum load, that is, step (2) in characteristic value and the S1 step in obtained load real load in Strength Calculation
Maximum total stress under mode is compared analysis；If characteristic value is greater than maximum total stress obtained in Strength Calculation,
Unstability does not occur for storage tank；Conversely, storage tank has unstability risk.
S6. when the result being calculated in step S3, S4 and S5, which is able to satisfy, to be required, then show the current work of the storage tank
It does not need to place under repair under condition, Daily Round Check can be reinforced by shortening round of visits, regular non-destructive testing guarantees the peace of storage tank
Quan Xing；If more than one calculated result is unsatisfactory for requiring, need corresponding according to the calculated result selection for being unsatisfactory for requiring
Treatment measures simultaneously calculate storage tank after processing again, have verified that treatment effect.
The calculation method of wind load suffered by storage tank, comprising the following steps: using wind speed for 12 grades of typhoons of 36m/s is basic wind
Speed analyzes the wind load that storage tank is subject to according to the pertinent regulations of wind load.
Following formula is that the wind load standard value acted perpendicularly on tall and slender structure surface unit area calculates:
wk=βzμsμzw0
In formula, βzWind pulse at-height z；
mμs- structural shape factor of wind load；
mμz- height variation coefficient of wind pressure；
w0- fundamental wind pressure (KN/m2)
Wherein βz=1+ ξ ε1ε2
X ξ-fluctuation amplifying coefficient in formula；
ε1- wind pressure pulsation and wind pressure height change etc. influence coefficient；
ε2- the vibration shape, construction profile influence coefficient.
The relationship of wind speed and wind pressure can be obtained according to the Bernoulli equation in hydrodynamics.What the wind speed of free stream generated
Wind pressure w on unit area0(KN/m2) are as follows:
In formula
w0--- the wind pressure (KN/m on unit area2)；
R ρ --- atmospheric density (t/m3)；n
v0--- wind speed (m/s).
The atmospheric conditions in different geographical locations are different, so atmospheric density is not also identical.Atmospheric density be air pressure,
The function of temperature and humidity can determine as the following formula:
In formula
T --- air themperature (DEG C)；
P --- air pressure (Pa)；
pvap--- vapour pressure (Pa).
Atmospheric density can also be according to the height above sea level z (m) of location approximate estimation as the following formula:
ρ=0.00125e-0.0001z(t/m3)r
When height above sea level is 0m, atmospheric density ρ=1.25kg/m3, then fundamental wind pressure w is known0(KN/m2):
Remaining parameter is not only related with the figure of storage tank and size, also related with ambient enviroment and surface roughness.According to
The specification handbook that wind load calculates, since the relevant parameter of height difference wind load is just different, so carrying out different height to storage tank
Piecewise analysis.
It is divided into two according to the wind load that storage tank is subject to by height to calculate, is the upper storage that average height is 9.375m respectively
Tank load F1, it is highly the lower storage tank F2, specific calculated result such as following table 2-1 and table 2-2 of 2.818m:
Wind load relevant parameter when table 2-1 wind speed is 36m/s
| Component | Highly (m) | Fluctuation amplifying coefficient ξ | Influence coefficient ε1 | Influence coefficient ε2 | Wind pulse β3 |
| Upper oil storage tank | 9.375 | 2.16 | 0.72 | 0.30 | 1.467 |
| Lower oil storage tank | 2.818 | 2.16 | 0.72 | 0.08 | 1.124 |
Wind load relevant parameter when table 2-2 wind speed is 36m/s
Loading real load, to calculate tank structure strength analysis method as follows: according to storage tank real work situation, storage tank by
To self gravity, internal hydrostatic pressure and effect (the wherein hydrostatic pressure for considering the wind load under inclement weather conditions
Consider the case where filling water in storage tank).The load condition being subject to according to storage tank passes through finite element analysis software to storage tank model
ANSYSWorkbench carries out the calculating of finite element static structure, specifically includes the following steps: storage tank model is imported into
In ANSYSWorkbench, since tank roof is reduced to lumped mass.Grid dividing is carried out to storage tank model.For model addition
Constraint, the bottom surface that storage tank is arranged is fixed constraint.According to storage tank stress condition, apply load for storage tank model, including storage tank by
The wind load being subject under the action of force 12 wind to self gravity load, storage tank by the static pressure of internal liquid, storage tank.It asks
Solution, obtains the stress distribution cloud atlas of storage tank.
Embodiment used in the present invention is one using the crude oil storage tank for surpassing 20 years, which selects 5000 cubes
Rice vertical cylinder steel (interior floating plate) welds storage tank, and the threedimensional model of storage tank is established according to storage tank two dimensional model figure, utilizes three
It is 11440mm that dimension modeling software solidworks, which establishes internal diameter r, is 6400mm with a thickness of 6mm height, is with a thickness of 8mm height
3000mm, with a thickness of 10mm, be highly 1500mm and be 1600mm with a thickness of 12mm height each one piece of annulus, be assembled
Storage tank three-dimensional model diagram, tank material select Q235 steel.It is required tank roof being reduced to lumped mass according to analysis, size is
22.16t.Storage tank three-dimensional simplified is imported in finite element analysis software ANSYS Workbench software, definition material is
Q235, storage tank select Meshing Method to divide for mapping surface grids.
To ensure safety in production, radiographic inspection is carried out to it and lossless detection method that magnetic powder inspection combines, as a result shown
Show exist inside the storage tank welding seam a large amount of lack of penetration.Therefore using the overall evaluation method of atmospheric storage tank of the invention to storage
The overall performance of tank evaluate as follows: when oil storage tank presence is a large amount of lack of penetration, the intensity of weld seam will be reduced, when weld seam
When intensity deficiency, it will weld seam is caused to destroy, it is therefore desirable to analyze weld seam there are it is lack of penetration constantly, the intensity of oil storage tank weld seam is big
It is small.
Selection highest first weld seam of lower part stress is studied, when the lack of penetration place's thickness of weld seam is reduced to wall thickness thickness
1/2 when, analyze oil storage tank weld seam intensity；Model is imported in ANSYS Workbench, lumped mass is added, divides net
Lattice, and apply load and constraint for model；Solution obtains oil storage tank Stress Map and maximum stress partial enlarged view: can by analysis
See, when weld seam is steel plate thickness 1/2, limit stress of the maximum stress of weld seam already close to Q235 steel under limiting condition.
Oil storage tank is during long-time service, however not excluded that therefore the weld seam of some positions can lead to Cracking Failure.
Embodiment one
Oil storage pot bottom second layer weld seam have 1/3 it is lack of penetration when stability analysis, make a concrete analysis of it is as follows: model is imported
In ANSYSWorkbench, when the oil storage pot bottom second layer has 1/3 weld cracking, by the contact between the Oil Storage Tank Model second layer
It is set as 2/3 contact surface binding, and adds fixed constraint in oil storage pot bottom；Apply gravity for Oil Storage Tank Model；For oil storage
Tank model applies wind load；It solves, the stress result after obtaining oil storage tank linear buckling, as shown in Fig. 2, by solving the line obtained
Property buckling stress result obtain, graph area show the buckling load factor be only 0.49413.Therefore when the oil storage pot bottom second layer welds
Be sewed with 1/3 it is lack of penetration when, unstability will occur for oil storage tank under the action of wind load and gravity.
Embodiment two
Stability analysis when oil storage pot bottom second layer weld seam has 1/3 lack of penetration (crack is discontinuous) is made a concrete analysis of as follows:
(assuming that there are two positions to crack for weld seam, and 1/6) weld cracking is all when weld cracking 1/3 and discontinuous cracking；Model is led
Enter in ANSYS Workbench, when the oil storage pot bottom second layer has 1/3 weld cracking and discontinuous weld cracking, by oil storage tank
Contact between the model bottom second layer is set as 2/3 binding, adds fixed constraint to Oil Storage Tank Model and applies load；It asks
Solution, the stress result after obtaining oil storage tank linear buckling, as shown in figure 3, being obtained by solving the linear buckling stress result obtained
Out, graph area shows that the buckling load factor is 1.5563.Therefore oil storage pot bottom second layer weld seam has that 1/3 is lack of penetration but crack
When discontinuous, oil storage tank is able to maintain stabilization under the action of wind load and gravity.
Embodiment three
Oil storage pot bottom second layer weld seam have 1/2 it is lack of penetration when stability analysis, make a concrete analysis of it is as follows: model is imported
In ANSYSWorkbench, when the oil storage pot bottom second layer has 1/2 weld cracking, by the contact between the Oil Storage Tank Model second layer
It is set as 1/2 contact surface binding, and adds fixed constraint in oil storage pot bottom；Apply gravity for Oil Storage Tank Model；For oil storage
Tank model applies wind load；It solves, the stress result after obtaining oil storage tank linear buckling, as shown in Figure 4；By solving the line obtained
Property buckling stress result obtain, graph area show the buckling load factor be 0.1391.Therefore work as oil storage pot bottom second layer weld seam
Have 1/2 it is lack of penetration when, unstability will occur for oil storage tank under the action of wind load and gravity.
Example IV
Stability analysis when oil storage pot bottom second layer weld seam has 1/2 lack of penetration (crack is discontinuous) is made a concrete analysis of as follows:
Model is imported in ANSYS Workbench, when the oil storage pot bottom second layer has 1/2 weld cracking and discontinuous weld cracking,
1/2 binding is set by the contact between the second layer of Oil Storage Tank Model bottom, fixed constraint is added to Oil Storage Tank Model and is applied
Load；It solves, the stress result after obtaining oil storage tank linear buckling, as shown in Figure 5；By solving the linear buckling stress obtained
As a result it obtains, graph area shows that the buckling load factor is 0.92749.Therefore oil storage pot bottom second layer weld seam has 1/2 lack of penetration
But crack it is discontinuous when, unstability will occur under the action of wind load and gravity for oil storage tank.
Tightness improvement is carried out to above-mentioned 20 years crude oil storage tank structures, selects the channel steel of four 36#C, length 12m,
Uniform welding is in storage tank surrounding, after being reinforced.
In the case where tank body contains the lack of penetration situation of part weld seam, for not carrying out analysis of stability containing saturating tank body containing commissure
Analysis, as a result as follows:
Embodiment five
The tank bottom second layer have 1/3 it is lack of penetration when stability, comprising the following steps:
By model import ANSYS Workbench in, the tank bottom second layer have 1/3 weld seam it is lack of penetration when, by storage tank mould
Contact between the type second layer is set as 2/3 contact surface binding, and adds fixed constraint in tank bottom；Storage tank model applies
Gravity；Apply wind load for storage tank model；It solves, obtains the stress result after reinforcing after storage tank linear buckling, as shown in Figure 6；It is logical
It crosses to solve and show that the linear buckling stress result after reinforcing obtains, graph area shows that the buckling load factor is only 2.4565, storage tank
After reinforcing tank bottom second layer weld seam have 1/3 it is lack of penetration when, under the action of wind and gravity will not unstability, reinforcement measure mentions
The high stability of oil storage tank.
Embodiment six
Tank bottom second layer weld seam has 1/3 lack of penetration and stability analysis when crack is discontinuous, comprising the following steps:
Weld seam is lack of penetration 1/3 and it is discontinuous lack of penetration when, it is assumed that weld seam is there are two position is lack of penetration, and weld seam is lack of penetration all
It is 1/6；Model is imported in ANSYS Workbench, the tank bottom second layer has 1/3 weld seam lack of penetration, and weld seam is discontinuous
When, 2/3 binding is set by the contact between the storage tank model bottom second layer, fixed constraint is added to storage tank model and applies load
Lotus；It solves, obtains storage tank linear buckling stress result after reinforcing, as shown in Figure 7；It is obtained by solution and is linearly bent after storage tank is reinforced
Transverse stress result show that graph area shows that the buckling load factor is 2.119.Therefore tank bottom second layer weld seam has 1/3 not weld
When thoroughly but crack is discontinuous, after storage tank reinforcing under the action of wind load and gravity, unstability, reinforcement measure do not improve storage to storage tank
The stability of oil tank.
Embodiment seven
Tank bottom second layer weld seam have 1/2 it is lack of penetration when stability analysis, specifically includes the following steps: model is imported
In ANSYSWorkbench, the tank bottom second layer have 1/2 weld seam it is lack of penetration when, the contact between the storage tank model second layer is set
It is set to 1/2 contact surface binding.And fixed constraint is added in tank bottom；Apply gravity for storage tank model；It is applied for storage tank model
Add wind load；It solves, obtains storage tank linear buckling stress result after reinforcing, as shown in Figure 8；It is linear after the reinforcing obtained by solution
Buckling stress result show that graph area shows that the buckling load factor is 3.555.Therefore when tank bottom second layer weld seam has 1/2
When lack of penetration, unstability will not occur for storage tank after reinforcing under the action of wind load and gravity, and reinforcement measure improves oil storage tank
Stability.
Embodiment eight
It is lack of penetration that tank bottom second layer weld seam has 1/2, and stability analysis when crack is discontinuous, specifically includes following step
It is rapid: model to be imported in ANSYS Workbench, the tank bottom second layer has 1/2 weld seam lack of penetration and when weld seam is discontinuous, will
Contact between the storage tank model bottom second layer is set as 1/2 binding, adds fixed constraint to storage tank model and applies load, asks
Solution, the stress result after obtaining storage tank linear buckling, as shown in Figure 9；By solve obtain storage tank reinforce after linear buckling stress
As a result it obtains, graph area shows that the buckling load factor is 3.6378.Therefore tank bottom second layer weld seam has 1/2 not weld after reinforcing
It is saturating but it is discontinuous when, unstability will not occur under the action of wind load and gravity for storage tank, and reinforcement measure improves oil storage tank
Stability.
By the above embodiments one to embodiment eight it is found that the present invention has filled up the storage tank flaw evaluation method of the current country
Blank, propose a kind of storage tank flaw evaluation system based on finite element modelling, calculate storage tank by finite element soft Ansys
Structural strength and stability, in the presence of crackle and incomplete fusion, analyze crackle and incomplete fusion point stresses intensity
The factor prevents crackle and incomplete fusion tip extension；Simultaneously, it is contemplated that two kinds of failure modes of strength failure and unstability of storage tank, energy
More all-sidedly and accurately evaluate the safe condition of storage tank.The present invention solve deficiency in terms of current state's inner storage tank Safety Assessment Standard with
Missing, the method for combining software to calculate by non-destructive testing early period detection, has evaluated from multi-angles such as structural mechanics, fracture mechanicses
The safe condition of storage tank, calculated result have higher reliability.
The above is only used to illustrate the technical scheme of the present invention and not to limit it, and those of ordinary skill in the art are to this hair
The other modifications or equivalent replacement that bright technical solution is made, as long as it does not depart from the spirit and scope of the technical scheme of the present invention,
It is intended to be within the scope of the claims of the invention.
Claims (6)
1. a kind of overall evaluation method to the atmospheric storage tank containing defect, which comprises the following steps: on detection storage tank
Property, size and the position of defect；According to tank structure and defective locations, size, property, defect is established in Ansys software
Storage tank model；Using Ansys software, loads real load and calculate tank structure intensity and storage tank stress intensity factor, load
Specific loading carries out stable calculation；To the tank structure intensity, storage tank stress intensity factor and stability result being calculated
It is evaluated, fully assesses the safe condition of storage tank；
The overall evaluation method, specially following steps:
S1. the property of defect, size and position on storage tank are detected using nondestructive means；
S2. finite element analysis Ansys software is used, in Ansys, according to the position of the structure of storage tank and defect, size, property
Matter establishes the storage tank model containing defect according to 1:1 equal proportion；
S3. Ansys software is used, real load is loaded, calculates tank structure intensity, the real load is according to storage tank itself
Situation and storage tank local environment calculate, and the calculating of the tank structure intensity includes maximum primary stress, maximum secondary stress, most
Big primary plus secondary stress, maximum total stress calculating, and by the maximum primary stress, most in calculated tank structure intensity
Big secondary stress, maximum primary plus secondary stress, maximum total stress and national standard " JB/T4732-2005 steel pressure vessel-
Analysis design standard " compared one by one, if there is more than one not meet standard requirements, need to take integral reinforcing storage tank or
The defect of person's maintenance stress higher position；
S4. when containing crackle or incomplete fusion in defect type, Ansys software need to be used to calculate storage tank crackle under real load
Or the point stresses intensity factor of incomplete fusion, by the point stresses intensity factor of crackle in storage tank or incomplete fusion and the storage tank institute
It is compared using the fracture toughness of material；If the stress intensity factor of storage tank is less than fracture toughness, crackle and incomplete fusion exist
It can't be extended under current working；If it is greater than or equal to fracture toughness, then crackle and incomplete fusion have generation under current working
A possibility that extension, need to repair in time, eliminate extension hidden danger；
S5. Ansys software is used, load specific loading carries out stable calculation, the spy of tank material buckling analysis is calculated
Unstability, which does not occur, for value indicative, that is, storage tank can bear maximum load；If characteristic value, which is greater than, loads reality obtained in Strength Calculation
Maximum total stress under load modes, then unstability does not occur for storage tank, loads if characteristic value is less than obtained in Strength Calculation
Maximum total stress under real load mode, then unstability has occurred for storage tank, then need to eliminate unstable position all defect or
Integral reinforcing is carried out to storage tank；
S6. when the result being calculated in step S3, S4 and S5, which is able to satisfy, to be required, then show under the storage tank current working
It does not need to place under repair, Daily Round Check can be reinforced by shortening round of visits, regular non-destructive testing guarantees the safety of storage tank
Property；If more than one calculated result is unsatisfactory for requiring, need according to the corresponding place of calculated result selection for being unsatisfactory for requiring
Reason measure simultaneously calculates storage tank after processing again, with verification processing effect.
2. a kind of overall evaluation method to the atmospheric storage tank containing defect according to claim 1, which is characterized in that described
The material of storage tank uses linear elastic materials.
3. a kind of overall evaluation method to the atmospheric storage tank containing defect according to claim 1, which is characterized in that described
Nondestructive means in step S1 selects radiographic inspection in conjunction with magnetic powder inspection, radiographic inspection in conjunction with penetrant inspection in one
Kind.
4. a kind of overall evaluation method to the atmospheric storage tank containing defect according to claim 1, which is characterized in that described
In step S3 load real load calculate tank structure intensity, specifically includes the following steps: a. according to the medium of storage tank, material,
Structure and max reassembly amount apply maximum level load to storage tank and from heavy load；B. local highest wind velocity and on the books is inquired
Since highest earthquake intensity, load maximum wind velocity load and maximum seismic (seismal；C. pass through in load step a and step b most
Big liquid level load, from heavy load, maximum wind velocity load and maximum seismic (seismal, calculate the storage tank in local most extreme environment
Stress distribution suffered by lower, the stress distribution once add secondary stress including maximum primary stress, maximum secondary stress, maximum
And maximum total stress.
5. a kind of overall evaluation method to the atmospheric storage tank containing defect according to claim 1, which is characterized in that described
Real load is loaded in step S4 and calculates the point stresses intensity factor of crackle or incomplete fusion in storage tank, specifically includes following step
It is rapid: according to linear elastic fracture mechanics theory, in Ansys software, to establish stress-strain field；Stress is calculated using Ansys software
Intensity factor；When establishing stress-strain field, firstly, for crackle or incomplete fusion on storage tank, opening for crackle or incomplete fusion is drawn
The line of mouth bottom；Secondly, defining the local coordinate system at description crackle or incomplete fusion tip first using KACLC order；Again, fixed
Justice is along the path of crack surface；Finally, calculating the point stresses intensity factor of defect or incomplete fusion position in storage tank；Wherein, exist
When Ansys software calculating stress strength factor, needing manual designated analysis type is one of plane stress or plane strain, needle
Plane stress is selected to the calculating of storage tank stress intensity factor.
6. a kind of overall evaluation method to the atmospheric storage tank containing defect according to claim 1, which is characterized in that described
In step S5, load specific loading carries out stable calculation, according to Plate Theory, the balance and unstability of linear elasticity hin shell member it
Between section very little, when linear elasticity hin shell member balance when, material is in elastic deformation；When linear elasticity hin shell member unstability
When, material enters surrender；Storage tank load specific loading stable calculation needs the surrender based on material to be calculated；Stability meter
Calculate specifically includes the following steps: (1) loaded on storage tank with the consistent specific loading of face regional location of actual loading, apply simultaneously
Add identical constraint condition；(2) in Ansys software, characteristic value is calculated using the Eigenvalue Buckling Analysis in software；
(3) characteristic value being calculated is obtained into the maximum load that storage tank does not occur to can bear when unstability multiplied by the specific loading of application
Lotus, since loaded load is unit load, obtained characteristic value is that unstability Shi Suoneng does not occur for storage tank in step (2)
The maximum load of receiving；(4) the maximum load i.e. step that can bear when unstability not being occurred for storage tank obtained in step (3)
(2) characteristic value in is always answered with the maximum under load real load mode obtained in Strength Calculation in the S1 step
Power is compared analysis；If characteristic value is greater than maximum total stress obtained in Strength Calculation, unstability does not occur for storage tank；Instead
It, storage tank unstability.
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| CN113094900A (en) * | 2021-04-07 | 2021-07-09 | 南京金创有色金属科技发展有限公司 | Method for analyzing safety risk of cryogenic liquid double-layer normal-pressure storage tank |
| CN113324165B (en) * | 2021-06-09 | 2022-12-13 | 中国特种设备检测研究院 | Defect-containing IV-type hydrogen storage bottle sample bottle and preparation method thereof |
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| CN113192070B (en) * | 2021-06-30 | 2021-09-10 | 深圳市超准视觉科技有限公司 | Weld image processing method and system based on computer vision |
| CN114792031B (en) * | 2022-03-23 | 2023-04-14 | 江苏省特种设备安全监督检验研究院 | Safety evaluation method for fusion surface defect-containing polyethylene pipe hot-melt joint |
| CN114936501B (en) * | 2022-07-20 | 2022-09-30 | 深圳市城市公共安全技术研究院有限公司 | Method and device for evaluating filling degree of vertical oil storage tank under wind pressure |
| CN115018386B (en) * | 2022-08-04 | 2022-10-21 | 深圳市城市公共安全技术研究院有限公司 | Method and device for evaluating safety of oil storage tank in explosion environment |
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| CN106644276A (en) * | 2017-01-11 | 2017-05-10 | 唐山市神州科贸有限公司 | Monitoring system for detecting tank leakage by utilizing distributed optical fiber |
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| CN103057877B (en) * | 2013-01-14 | 2015-01-14 | 中国石油大学(华东) | Arch-top storage tank with reticulated shell |
| CN103870662A (en) * | 2014-04-01 | 2014-06-18 | 青岛科技大学 | Method for predicting residual life of storage tank |
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| CN106644276A (en) * | 2017-01-11 | 2017-05-10 | 唐山市神州科贸有限公司 | Monitoring system for detecting tank leakage by utilizing distributed optical fiber |
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