CN207650042U - Plastic pipe service life evaluating apparatus - Google Patents
Plastic pipe service life evaluating apparatus Download PDFInfo
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- CN207650042U CN207650042U CN201721675476.0U CN201721675476U CN207650042U CN 207650042 U CN207650042 U CN 207650042U CN 201721675476 U CN201721675476 U CN 201721675476U CN 207650042 U CN207650042 U CN 207650042U
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Abstract
The utility model is related to plastic pipe test devices, it is intended to which solving the problems, such as the life test of existing plastic pipe, very time-consuming, provides plastic pipe service life evaluating apparatus comprising electronic tensile machine, temperature control box, mounting bracket, at least one electron microscope.Electronic tensile machine includes lower collet and upper grip；Upper grip is sequentially connected in driving device, and can be under the drive of driving device along axial reciprocating tensile sample；The stretched operation portion of electronic tensile machine is located in the temperature controlled compartment of temperature control box；Mounting bracket is set on pedestal, and has at least one mounting head；Electron microscope is installed in the mounting head of mounting bracket, and the direction of the camera lens of electron microscope is perpendicular to sample axis, and face precrack；The data-interface of electron microscope is electrically connected to a display, and display is for showing that the precrack of sample is in the amplified figure of electron microscope.The utility model has the beneficial effects that the test period can be substantially reduced.
Description
Technical field
The utility model is related to plastic pipe test device fields, in particular to plastic pipe service life evaluating apparatus.
Background technology
Currently, the resistance to slow crack growth performance test evaluation method of plastic pipe include mainly notch pipe experiment (NPT), it is complete
Notch tensile creep test (FNCT), Pennsylvania Notch tension test (PENT), notch ring test (NRT) and point load examination
It tests (PLT) etc..The evaluation cycle of above-mentioned evaluation method is long, usually at 1 year or 104Hour (about 13 months).It comments for a long time
The valence period also counteracts the resin dedicated development rate of plastic pipe.Moreover, in evaluation cycle, it is difficult to observe the mistake of sample
Effect, and then the microscopic pattern after sample failure can not be observed, cause evaluation result inaccurate.
Utility model content
The purpose of the utility model is to overcome the deficiencies in the prior art, provide a kind of plastic pipe service life evaluating apparatus,
It can be significantly reduced and be commented by using the method that plastic pipe service life evaluating apparatus in the utility model evaluates and tests the plastic pipe service life
The valence period, and the microscopic pattern after sample failure can be observed in evaluation cycle, improve the accuracy of evaluation result.
What the embodiments of the present invention were realized in：
The utility model embodiment provides a kind of plastic pipe service life evaluating apparatus, for by back and forth being drawn sample
The mode stretched determines the service life of plastic pipe, and sample is the cylinder being made of material identical as plastic pipe to be measured, and is tried
The circumferential surface of sample has the precrack perpendicular to its axis comprising：It is electronic tensile machine, temperature control box, mounting bracket, at least one
Electron microscope.Electronic tensile machine includes the lower collet for being supported on its pedestal and being used to that sample lower end to be clamped, and for being clamped
The upper grip of sample upper end；Upper grip is sequentially connected in driving device, and can be under the drive of driving device along axial reciprocating
Tensile sample；The stretched operation portion of electronic tensile machine is located in the temperature controlled compartment of temperature control box；Mounting bracket is set on pedestal, and
With at least one mounting head；Electron microscope is installed in the mounting head of mounting bracket, and the camera lens of electron microscope
Towards perpendicular to sample axis, and face precrack；The data-interface of electron microscope is electrically connected to a display, display
For showing that the precrack of sample is in the amplified figure of electron microscope.
Plastic pipe service life evaluating apparatus in the present embodiment in use, be held on electronics respectively by the sample both ends made
Between the upper grip of stretching-machine and lower collet；Make at the precrack on the camera lens face sample of electron microscope；Then start
Electronic tensile machine carries out reciprocal tension test to sample.While reciprocal tension test, the precrack for observing sample is paid attention to
Pass through the imaging after electron microscopy over the display；When the cracked germinating of precrack, electronics is drawn record at this time
Stretch the stretching cycle-index of machine.The service life of plastic pipe is evaluated by cycle-index：Cycle-index is more when cracked germinating
The service life for then evaluating plastic pipe is bigger.
Plastic pipe service life evaluating apparatus in the present embodiment by cupping machine cyclic tension and passes through electron microscopic
Cyclic tension number evaluates the service life of plastic pipe when the cracked germinating of sem observation sample, compared with prior art in notch
Pipe tests (NPT), full notch tensile creep test (FNCT), Pennsylvania Notch tension test (PENT), notch ring test
(NRT) and point load testing (PLT) etc.,
The plastic pipe service life evaluating apparatus provided using the utility model embodiment is used to evaluate and test the plastic pipe service life
Method, can in tens hours even in several hours just it is observed that sample crack initiation.The utility model embodiment
The plastic pipe life assessment method of offer, greatly reduces evaluation cycle, helps to be promoted that plastic pipe is resin dedicated opens
Send out speed.Also, the plastic pipe life assessment method provided by the utility model embodiment, can see in evaluation cycle
The microscopic pattern after sample failure is measured, the accuracy of evaluation result is improved.
In an embodiment of the present embodiment：
There are four electron microscope is total；Four electron microscopes are circumferentially uniformly distributed around sample axis, and each electronics
Microscopical camera lens is respectively perpendicular alignment precrack.
In an embodiment of the present embodiment：
The camera lens interval specimen surface 5-10m of electron microscope.
In an embodiment of the present embodiment：
Pedestal is box structure, and display is embedded at the side of the pedestal of electronic tensile machine, and display faces outwardly.
In an embodiment of the present embodiment：
Mounting bracket includes that the mounting base being fixed on pedestal and multiple one end are connected to the mounting base other end for connecting
The Universal pipe of mounting head；The camera lens of electron microscope is installed on mounting head, and the lead of electron microscope passes through universal tube cavity, and
The data connector of end passes through the top plate of pedestal and is electrically connected display.
In an embodiment of the present embodiment：
Electronic tensile machine uses mesa structure comprising pedestal, two vertical intervals are connected to the guide rod of pedestal, fixed company
It is connected to the crossbeam of two guide rods, is fixedly connected on the driving device of crossbeam.
In an embodiment of the present embodiment：
Temperature control box covers in the top of institute's electronic tensile machine from top to bottom, and the lower end of temperature control box is fixed on electronic tensile machine
Pedestal.
In an embodiment of the present embodiment：
The switch for starting and stopping for controlling electronic tensile machine is additionally provided on pedestal；Switch electrical connection driving device, is used
In the startup and stopping that controlling the driving device.
In an embodiment of the present embodiment：
The temperature-control range of temperature control box includes 18-28 DEG C.
In an embodiment of the present embodiment：
Upper grip includes fixed part and rotation section；The lower end of fixed part be equipped with ship and resell on another market, rotation section be by roof and side enclosure wall
The cup-like structure of the downwardly facing opening of composition, roof are rotatably connected at shipping and reselling on another market for fixed part, and being capable of the portion's of being relatively fixed rotation；
Side enclosure wall lower end is equipped with internal thread, and internal thread is configured for the external screw thread of screw-thread fit sample upper end peripheral surface；Lower collet
For opening up cup-like structure, lower collet is fixedly connected with pedestal, and the aperture position of lower collet is equipped with internal thread, is used for screw thread
Coordinate the external screw thread of the peripheral surface of the lower end of sample.
In summary it describes, the fast, evaluation structure with experiment process of the plastic pipe service life evaluating apparatus in the present embodiment
Accurate advantageous effect.
Description of the drawings
It, below will be to required use in embodiment in order to illustrate more clearly of the technical solution of the utility model embodiment
Attached drawing be briefly described, it should be understood that the following drawings illustrates only some embodiments of the utility model, therefore should not be by
Regard the restriction to range as, for those of ordinary skill in the art, without creative efforts, may be used also
To obtain other relevant attached drawings according to these attached drawings.
Fig. 1 is the structural schematic diagram of the plastic pipe service life evaluating apparatus in the utility model embodiment；
Fig. 2 sees the structural schematic diagram for carrying out sample used in service life evaluating apparatus for the plastics in the utility model embodiment；
Fig. 3 is the schematic diagram of the distribution mode of the electron microscope in the utility model embodiment；
Fig. 4 is that the upper grip of plastic pipe service life evaluating apparatus in the utility model embodiment, sample, lower collet are matched
The schematic diagram (explosion displaying) of conjunction relationship；
Fig. 5 be the utility model embodiment in, during experiment, the change curve of tensile stress；
The first double logarithmic chart in Fig. 6 the utility model embodiments；
Fig. 7 is second of double logarithmic chart in the utility model embodiment.
Icon：100- plastic pipe service life evaluating apparatus；10- electronic tensile machines；11- pedestals；Collet under 12-；It is pressed from both sides on 13-
Head；13a- fixed parts；The rotation sections 13b-；13c- ships and resell on another market；14- driving devices；15- guide rods；16- crossbeams；17- is switched；20- temperature controls
Case；30- mounting brackets；31- mounting heads；32- mounting bases；33- Universal pipes；40- electron microscopes；41- camera lenses；42- leads；
50- displays；W0- samples；W1- precracks；W2- external screw threads.
Specific implementation mode
It is new below in conjunction with this practicality to keep the purpose, technical scheme and advantage of the utility model embodiment clearer
Attached drawing in type embodiment, the technical scheme in the utility model embodiment is clearly and completely described, it is clear that is retouched
The embodiment stated is the utility model a part of the embodiment, instead of all the embodiments.Usually here described in attached drawing and
The component of the utility model embodiment shown can be arranged and be designed with a variety of different configurations.
Therefore, the detailed description of the embodiments of the present invention to providing in the accompanying drawings is not intended to limit requirement below
The scope of the utility model of protection, but it is merely representative of the selected embodiment of the utility model.Based in the utility model
Embodiment, every other embodiment obtained by those of ordinary skill in the art without making creative efforts, all
Belong to the range of the utility model protection.
It should be noted that：Similar label and letter indicate similar terms in following attached drawing, therefore, once a certain Xiang Yi
It is defined, then it further need not be defined and explained in subsequent attached drawing in a attached drawing.
In the description of the present invention, it should be noted that if occur term "center", "upper", "lower", " left side ",
The orientation or positional relationship of the instructions such as " right side ", "vertical", "horizontal", "inner", "outside" is orientation based on ... shown in the drawings or position
Relationship or the utility model product using when the orientation or positional relationship usually put, be merely for convenience of describing this reality
With novel and simplified description, does not indicate or imply the indicated device or element must have a particular orientation, with specific
Azimuth configuration and operation, therefore should not be understood as limiting the present invention.If in addition, occurring in the description of the utility model
Term " first ", " second " etc. are only used for distinguishing description, are not understood to indicate or imply relative importance.
If being not offered as requiring component in addition, occurring the terms such as term "horizontal", "vertical" in the description of the utility model
Abswolute level or pendency, but can be slightly tilted.If "horizontal" refers to only that its direction is more horizontal with respect to for "vertical",
It is not to indicate that the structure is had to fully horizontally, but can be slightly tilted.
Embodiment
Fig. 1 is the structural schematic diagram of the plastic pipe service life evaluating apparatus 100 in the utility model embodiment (with void in figure
Line illustrates sample W0 used).Referring to Fig. 1, the plastic pipe service life evaluating apparatus 100 in the present embodiment is used for by sample
The mode that W0 is back and forth stretched determines the service life of plastic pipe, and referring to Fig. 2, sample W0 is by material identical as plastic pipe to be measured
Expect the diameter D constituted, the cylinder of length L, and the circumferential surface of sample W0 has the precrack W1 perpendicular to its axis.Its
In, precrack W1 is the annular groove for being opened in sample W0 circumferential surfaces.It should be noted that the diameter D of sample W0 can be in 13mm-
It is selected between 15mm, the length L of sample W0 can be selected between 70mm-mm.Further, the diameter of sample W0
D can be controlled between 13.5mm-14.5mm, and the length L of sample W0 can be controlled between 90mm-mm.In such manner, it is possible to avoid
Because the undersized of sample W0 leads to not accurately show test result, avoid because the oversized of sample W0 causes to comment
The problem of valence excessive cycle.In the present embodiment, the length of a diameter of 14mm of sample W0, sample W0 are 95mm.Precrack
The centre position in sample W0 axial directions is arranged in W1.In addition, the depth N of precrack W1 is 1.49mm-1.51mm, and it is prefabricated
Axial direction of the depth direction of crackle W1 perpendicular to sample W0.Precrack W1's is deep-controlled in 1.49mm-1.51mm, can keep away
The problem of exempting to cause new crackle to be difficult to germinate since precrack W1 depth is too small, and then extending evaluation cycle, also can
It avoids that sample W0 is caused to be broken in the case where stretching repeatedly since precrack W1 depth is excessive, and then cannot achieve asking for test objective
Topic.
Referring again to Fig. 1, plastic pipe service life evaluating apparatus 100 includes：Electronic tensile machine 10, temperature control box 20, installation branch
Frame 30, at least one electron microscope 40.
Wherein, electronic tensile machine 10 includes the lower collet 12 for being supported on its pedestal 11 and being used to that the lower ends sample W0 to be clamped,
With the upper grip 13 for the upper ends sample W0 to be clamped；Upper grip 13 is sequentially connected in driving device 14, and can be in driving device
Along axial reciprocating tensile sample W0 under 14 drive；The stretched operation portion of electronic tensile machine 10 is located at the temperature controlled compartment of temperature control box 20
In；Mounting bracket 30 is set on pedestal 11, and has at least one mounting head 31；Electron microscope 40 is installed on installation branch
In the mounting head 31 of frame 30, and the direction of the camera lens 41 of electron microscope 40 is perpendicular to sample W0 axis, and face is prefabricated splits
Line W1；The data-interface of electron microscope 40 is electrically connected to a display 50, and display 50 is for showing that the prefabricated of sample W0 is split
Line W1 is in the amplified figure of electron microscope 40.In the present embodiment, coordinate referring to Fig. 3, electron microscope 40 shares four
It is a；Four electron microscopes 40 are circumferentially uniformly distributed around sample W0 axis, and the camera lens 41 of each electron microscope 40 is distinguished
Perpendicular alignmnet precrack W1.The camera lens 41 of electron microscope 40 is spaced sample W0 surface 5-10m.The number of electron microscope 40
Amount can be set in other embodiments one, two, three, five it is even more.
In the present embodiment, pedestal 11 is box structure, and display 50 is embedded at the side of the pedestal 11 of electronic tensile machine 10,
And display faces outwardly.Optionally, the display screen of display 50 is divided into four pieces, four 40 visuals field of electron microscope of every piece of corresponding display
Interior enlarged drawing.
The set-up mode of mounting bracket 30 in the present embodiment is：Mounting bracket 30 includes the installation being fixed on pedestal 11
Seat 32 and multiple one end are connected to Universal pipe 33 of 32 other end of mounting base for connecting mounting head 31；Electron microscope 40
Camera lens 41 is installed on mounting head 31, and the lead 42 of electron microscope 40 passes through 33 inner cavity of Universal pipe, and the data connector of end is worn
It crosses the top plate of pedestal 11 and is electrically connected display 50.The Universal pipe 33 that the place is said refers to semiflexible pipe fitting, is free to
It is bent and is positioned at the direction bent to and posture.It can be easily by electronic display by the connection of Universal pipe 33 in the present embodiment
The camera lens 41 of micro mirror 40 is adjusted to the precrack W1 of vertical face sample W0, and keeps the spacing of setting.
In the present embodiment, electronic tensile machine 10 uses mesa structure comprising the vertical interval of pedestal 11, two is connected to bottom
The guide rod 15 of seat 11 is fixedly connected on the crossbeam 16 of two guide rods 15, is fixedly connected on the driving device 14 of crossbeam 16.Electronics is drawn
It stretches machine 10 and common type can be used, such as universal electrical stretching-machine can be used.Temperature control box 20 covers in institute's electronics and draws from top to bottom
The top of machine 10 is stretched, and the lower end of temperature control box 20 is fixed on the pedestal 11 of electronic tensile machine 10.The temperature-control range of temperature control box 20
Including at least 18-28 DEG C.The set temperature of temperature control box 20 is set in the present embodiment as 23 DEG C, i.e. sample W0 is maintained at 23 DEG C
Cyclic tension in environment.Notch pipe experiment (NPT) in compared with the prior art, full notch tensile creep test (FNCT), guest
The experiment of sunset Fa Niya notch tension test (PENT), notch ring test (NRT) and point load testing (PLT) etc. is needed at 80 DEG C
In the environment of carry out, and there is still a need for 1 year or 104Hour (about 13 months) could complete test evaluation, the plastics in the present embodiment
Tubing service life evaluating apparatus 100 can carry out under lower temperature (such as 23 DEG C), and can complete to try within a short period of time
It tests and (will be described below).
In an embodiment of the present embodiment, it is additionally provided on pedestal 11 and starts and stop for controlling electronic tensile machine 10
Switch 17 only；Switch 17 is electrically connected driving device 14, startup and stopping for controlling the driving device 14.Switch 17 is set
It is convenient when experiment occurs surprisingly needing to stop to set, quick closedown.
Referring to Fig. 4, in an embodiment of the present embodiment, upper grip 13 includes fixed part 13a and rotation section 13b；
The lower end of fixed part 13a is equipped with the cup-like structure that 13c, rotation section 13b are the downwardly facing opening being made of roof and side enclosure wall of shipping and reselling on another market,
Roof is rotatably connected at the 13c that ships and resell on another market of fixed part 13a, and can be relatively fixed portion 13a rotations；Side enclosure wall lower end is equipped with
Internal thread, internal thread are configured for the external screw thread W2 of the upper ends screw-thread fit sample W0 peripheral surface；Lower collet 12 is opening court
On cup-like structure, lower collet 12 is fixedly connected with pedestal 11, and the aperture position of lower collet 12 is equipped with internal thread, matches for screw thread
Close the external screw thread W2 of the peripheral surface of the lower end of sample W0.It is needed axial the two of sample W0 using the upper grip 13, lower collet 12
External screw thread W2 is opened up at the peripheral surface at end.When clamping, the lower thread of sample W0 is first connected to lower collet 12；Then make folder
The rotation section 13b that upper grip 13 is rotated while first 13 downlink, makes the internal thread of rotation section 13b be threadedly connected to the upper ends sample W0
External screw thread W2, complete the clamping of sample W0.Clamping can carry out the tension test of sample W0 after completing.
Plastic pipe service life evaluating apparatus 100 in the present embodiment is in use, the both ends sample W0 made are clamped respectively
Between the upper grip 13 and lower collet 12 of electronic tensile machine 10；Make on the 41 face sample W0 of camera lens of electron microscope 40
At precrack W1；Then start electronic tensile machine 10 and reciprocal tension test is carried out to sample W0.In the same of reciprocal tension test
When, notice that the precrack W1 for observing sample W0 passes through the imaging after 40 method of electron microscope on display 50；When prefabricated
When the cracked germinatings of crackle W1, the stretching cycle-index of record electronic tensile machine 10 at this time.Plastics are evaluated by cycle-index
The service life of tubing：When cracked germinating cycle-index more at most evaluate plastic pipe service life it is bigger.
Plastic pipe service life evaluating apparatus 100 in the present embodiment by cupping machine cyclic tension and passes through electronic display
Cyclic tension number evaluates the service life of plastic pipe when micro mirror 40 observes sample W0 cracked germinating, compared in the prior art
Notch pipe experiment (NPT), full notch tensile creep test (FNCT), Pennsylvania Notch tension test (PENT), notch
Ring test (NRT) and point load testing (PLT) etc., with experiment process, fast, test temperature requires low advantageous effect.
In the present embodiment, the plastic pipe life assessment method based on the plastic pipe service life evaluating apparatus 100 includes such as
Lower step：
S01：Specimen clamping.
In the present embodiment, the upper and lower side of sample W0 is clamped in upper grip 13 and lower collet 12 respectively.Wherein, sample W0
Clip position and precrack W1 between the shortest distance be 5mm-10mm.In other words, clamping piece and precrack W1 it
Between shortest distance Lmin be 5mm-10mm.Lmin is set within the above range, can to avoid clamping piece in drawing process with it is pre-
The distance between crackle W1 processed excessive the case where causing crackle that can not germinate near precrack W1, finds, can also avoid drawing
The distance between clamping piece and precrack W1 are too small during stretching causes sample W0 to be pulled off to cannot achieve test objective
The case where occur.In the present embodiment, the shortest distance Lmin between clamping piece and precrack W1 is 7.5mm.
S02：Electronic tensile machine 10 is set to use predeterminated frequency f tensile sample W0, tensile stress is maximum pre- in drawing process
If gradually reciprocal variation between stress Fmax and minimum default stress Fmin, it is once a cycle that tensile stress, which often changes,.
Fig. 5 is please referred to, Fig. 5 is the change curve of tensile stress during tensile sample W0.It can from figure
Go out, tensile stress gradually increases to maximum preset stress Fmax from the default stress Fmin of minimum in drawing process, then again from
Maximum preset stress Fmax is gradually decrease to minimum default stress Fmin.And so on, sample W0 is stretched.Wherein, it draws
Stretch that stress gradually increases to the time of maximum preset stress Fmax from the default stress Fmin of minimum and tensile stress maximum preset is answered
The time that power Fmax is gradually decrease to minimum default stress Fmin is identical.Tensile stress is pre- in the default stress Fmin of minimum and maximum
If it is a cycle to change between stress Fmax once.
The unit of the default stress Fmin and maximum preset stress Fmax of minimum is Mpa, and the unit of predeterminated frequency f is Hz.
Predeterminated frequency f can be selected between 5Hz-15Hz, can be caused in this way to avoid because predeterminated frequency f is too small
The problem of evaluation cycle extends, can also avoid leading to not accurately reflect asking for plastic pipe service life because predeterminated frequency f is excessive
Topic.In the present embodiment, predeterminated frequency f=10Hz.
In addition, in the present embodiment, maximum preset stress Fmax is configured according to the density of sample W0 materials.If examination
The density of sample W0 materials is big, then increases maximum preset stress Fmax；If the density of sample W0 materials is small, reduce maximum pre-
If stress Fmax.
It also needs to further illustrate, the minimum ratio R for presetting stress Fmin and maximum preset stress Fmax is more than etc.
In 0.1, it is less than or equal to 1.0.Sample W0 applications are led enough in such manner, it is possible to ensure that minimum default stress Fmin can also reach
The effect of the load of crack initiation is caused, evaluation cycle is reduced.In the present embodiment, minimum default stress Fmin is answered with maximum preset
Ratio R=0.5 of power Fmax.
S03：The surface that sample W0 is observed using electron microscope 40, when precrack W1 nearby germinates new crackle,
Record change frequency Nini and the range of stress △ σ of tensile stress；
Change frequency Nini is converted into stretching time T；
Wherein, △ σ=Fmax-Fmin, T=Nini/ (0*f)；
The unit of △ σ, Fmax and Fmin are Mpa；The unit of T is hour；The unit of f is Hz；The unit of Nini is
It is secondary.
Referring once again to Fig. 1, in the present embodiment, the surface of sample W0 is observed using electron microscope 40.Observe sample
The surface of W0 is to judge whether precrack W1 has nearby germinated new crackle.It is new due to what is germinated near precrack W1
Flaw size it is very small, therefore, in order to grasp immediately precrack W1 Crack Nears germinate situation, in the present embodiment
The middle surface that sample W0 is observed using electron microscope 40.Further, in order to comprehensively observe the surface of sample W0,
In the present embodiment, multiple electron microscopes 40 are evenly arranged around sample W0.Further, referring to Fig. 3, using four electronic displays
Micro mirror 40 is evenly arranged around sample W0, and the angle between adjacent electron microscope 40 is 90 °.It can comprehensively observe in this way
Sample W0 shows to grasp precrack W1 Crack Nears germinating situation immediately.Further, in the present embodiment, electron microscopic
40 perpendicular alignmnet precrack W1 of mirror, in other words electron microscope 40 is vertical with the axis of sample W0.In this way, precrack W1
Above and below the new crackle that germinates can accurately be collected by electron microscope 40, and above precrack W1 and under
The new crackle of Fang Mengsheng can be clearly showed that, is conducive to staff and is grasped precrack W1 Crack Nears germinating feelings
Condition.
After staff observes that precrack W1 has nearby germinated new crackle, the change frequency of tensile stress is recorded
Nini and range of stress △ σ.The unit of change frequency Nini is secondary, is equivalent to the circulating cycle issue of tensile stress.Stress model
The difference that △ σ refer to maximum preset stress Fmax and minimum default stress Fmin, i.e. △ σ=Fmax-Fmin are enclosed, the unit of △ σ is
Mpa.Then, change frequency Nini is converted into stretching time T.The unit of T=Nini/ (3600*f), T are hour.
Draw double logarithmic chart.It is the drafting double logarithmic chart in the present embodiment with reference to Fig. 6, Fig. 6.It is sat in double-log
In marking on a map, abscissa is stretching time T, and ordinate is range of stress △ σ.Using T and △ σ obtained above as log-log coordinate
A coordinate points in figure are plotted in double logarithmic chart.
S04：Step S01- step S03 are repeated using different range of stress △ σ, obtain multiple stretching time T.According to more
A range of stress △ σ and corresponding stretching time T are obtained to the coordinate points in a drafting double logarithmic chart, by these coordinates
Point-rendering is in double logarithmic chart.Then the line of T and △ σ relationships are indicated according to the coordinate point-rendering in double logarithmic chart
Item, and then complete the drafting of double logarithmic chart.According to double logarithmic chart, you can judge that the material for constituting sample W0 is making
After plastic pipe, the relationship of service life and range of stress △ σ.Wherein, stretching time T is bigger, indicates to constitute sample W0
Material make plastic pipe service life it is longer.
Plastic pipe life assessment method provided in this embodiment executes in the environment of 18 DEG C -28 DEG C, you can ensures
Just it is observed that crack initiation in tens hours even several hours, and then evaluation cycle is greatly reduced, helps to be promoted
The resin dedicated development rate of plastic pipe.Meanwhile plastic pipe life assessment method provided in this embodiment, in evaluation cycle
The interior microscopic pattern that can be observed after sample W0 failures, improves the accuracy of evaluation result.Relative to existing notch pipe
Test (NPT), full notch tensile creep test (FNCT), Pennsylvania Notch tension test (PENT), notch ring test
(NRT) it is tested at 80 DEG C or so with the evaluation methods needs such as point load testing (PLT), plastic pipe provided in this embodiment
Life assessment method is low to environment temperature requirement, can effectively reduce evaluation cost.Further, in the present embodiment, plastics
Tubing life assessment method executes in the environment of 23 DEG C.
It should be further noted that plastic pipe life assessment method provided in this embodiment further includes making sample W0
The step of, make sample W0 the step of include：
(1) cylindrical bar is made in injection molding；
(2) the cylindrical bar is cut, semi-finished product are obtained；
(3) the prefabricated of annular is processed in the circumferential surface of the semi-finished product with the blade feeding rate of 0.03mm-0.04mm/ circles
Crackle W1 obtains sample W0.
With the blade feeding rate processing precrack W1 of 0.03mm-0.04mm/ circles, it can be ensured that the surfaces precrack W1
It is smooth.In such manner, it is possible to which the excessively slow caused surfaces precrack W1 of blade feeding rate is avoided burr occur, and then influence newly
The problem of crack initiation；Also it can avoid occurring around the too fast caused precrack W1 in process of blade feeding rate
The problem of crackle.So that evaluation result is more accurate.
In the following, being described further to plastic pipe life assessment method provided in this embodiment：
(condition used in the present embodiment) if other conditions are the same is shown in table 1, is selected different pre-
If frequency f executes the case where plastic pipe life assessment method.
Table 1
Predeterminated frequency f 3Hz4Hz5Hz10Hz 15Hz 16Hz 17Hz
The new crackle 73 of the new crackle germinating in 85 hours of the new crackle germinating in 110 hours of implementing result germinating in 121 hours
Hour germinate 70 hours new 50 hours sample W0 of crackle of germinating of new crackle large area occur and pull 47 hours sample W0 to go out
Existing large area is pulled
As can be seen from Table 1：When f is less than 5Hz, evaluation cycle is long；As 5Hz≤f≤15Hz, evaluation cycle is big
Amplitude shortens；Cause sample W0 large area occur when f is more than 15Hz, in the short time to pull, lead to not to plastic pipe
Service life is evaluated.
(condition used in the present embodiment) if other conditions are the same is shown in table 2, selects different numerical value
R execute plastic pipe life assessment method the case where.
Table 2
R 0.05 0.08 0.10.50.60.70.95
The new crackle 73 of the new crackle germinating in 87 hours of the new crackle germinating in 141 hours of implementing result germinating in 152 hours
Hour germinates the new crackle of the new crackle germinating in 140 hours of the new crackle germinating in 110 hours of new crackle germinating in 78 hours
As can be seen from Table 2：When R is less than 0.1, since the default stress Fmin of minimum is too small, lead to not to sample
W0 applies sufficiently large load, so that new crack initiation time lengthening, increases evaluation cycle；When 0.1≤R≤0.6
When, since the default stress Fmin of minimum increases so that the new crack initiation time shortens, and then is played after the evaluation shortened；Work as R
When more than 0.6, since minimum default difference between stress Fmin and maximum preset stress Fmax becomes smaller, sample W0 is caused to bear
Alternating load reduce, but also new crack initiation time lengthening, increases evaluation cycle.
The present embodiment use embodiment plastic pipe life assessment method above-mentioned, respectively to PE100-1, PE100-2,
Tetra- kinds of different materials of PE100RC-3 and PE100RC-4 are tested, and by above-mentioned four kinds of materials expression T and △ σ relationships line
Item is plotted in the same double logarithmic chart.Fig. 7 is the double logarithmic chart in the present embodiment.By Fig. 7, can compare
Four kinds of materials are stated at identical range of stress △ σ, the difference of stretching time T.At identical range of stress △ σ, when stretching
Between the bigger materials of T, the service life of manufactured plastic pipe is longer.In this way, can be to plastic tube made of different materials
The service life of material carries out comparative evaluation, to which the research and development resin dedicated to plastic pipe provide reference.
Obviously, above-described embodiment of the utility model is used for the purpose of clearly illustrating the utility model example, and
It is not the restriction to the embodiment of the utility model.For those of ordinary skill in the art, in above description
On the basis of can also make other variations or changes in different ways.There is no need and unable to give all embodiments
It is exhaustive.All any modification, equivalent and improvement made within the spirit and principle of the present invention etc., should be included in
Within the protection domain of the utility model claims.
Claims (10)
1. a kind of plastic pipe service life evaluating apparatus, for determining plastic pipe by way of back and forth being stretched to sample
In the service life, the sample is the cylinder being made of material identical as plastic pipe to be measured, and the circumferential surface of the sample is with vertical
Directly in the precrack of its axis, it is characterised in that：
The plastic pipe service life evaluating apparatus includes：
Electronic tensile machine；The electronic tensile machine includes the lower folder for being supported on its pedestal and being used to that the sample lower end to be clamped
Head, and the upper grip for sample upper end to be clamped；The upper grip is sequentially connected in driving device, and can be filled in the driving
Under the drive set the sample is stretched along axial reciprocating；
The stretched operation portion of temperature control box, the electronic tensile machine is located in the temperature controlled compartment of the temperature control box；
Mounting bracket is set on the pedestal, and has at least one mounting head；
At least one electron microscope, the electron microscope are installed in the mounting head of the mounting bracket, and the electricity
The direction of the microscopical camera lens of son is perpendicular to the sample axis, and precrack described in face；The number of the electron microscope
It is electrically connected to a display according to interface, the display is for showing that the precrack of the sample is in the electron microscope
Amplified figure.
2. plastic pipe service life evaluating apparatus according to claim 1, it is characterised in that：
There are four the electron microscope is total；
Four electron microscopes are circumferentially uniformly distributed around the sample axis, and the camera lens of each electron microscope
It is respectively perpendicular alignment precrack.
3. plastic pipe service life evaluating apparatus according to claim 1, it is characterised in that：
Specimen surface 5-10mm described in the camera lens interval of the electron microscope.
4. plastic pipe service life evaluating apparatus according to claim 2, it is characterised in that：
The pedestal is box structure, and the display is embedded at the side of the pedestal of the electronic tensile machine, and display surface court
Outside.
5. plastic pipe service life evaluating apparatus according to claim 4, it is characterised in that：
The mounting bracket includes that the mounting base being fixed on the pedestal and multiple one end are connected to the mounting base other end
Universal pipe for connecting the mounting head；
The camera lens of the electron microscope is installed on the mounting head, and the lead of the electron microscope passes through in the Universal pipe
Chamber, and the data connector of end passes through the top plate of the pedestal and is electrically connected the display.
6. plastic pipe service life evaluating apparatus according to claim 1, it is characterised in that：
The electronic tensile machine uses mesa structure comprising the pedestal, two vertical intervals are connected to leading for the pedestal
Bar, the crossbeam for being fixedly connected on two guide rods, the driving device for being fixedly connected on the crossbeam, the driving device
Telescopic end be sequentially connected the upper grip, for driving the upper grip to drive the reciprocal tension test of sample.
7. plastic pipe service life evaluating apparatus according to claim 6, it is characterised in that：
The temperature control box covers in the top of institute's electronic tensile machine from top to bottom, and the lower end of the temperature control box is fixed on the electricity
The pedestal of sub- stretching-machine.
8. plastic pipe service life evaluating apparatus according to claim 1, it is characterised in that：
The switch for starting and stopping for controlling the electronic tensile machine is additionally provided on the pedestal；Described in the switch electrical connection
Driving device, startup and stopping for controlling the driving device.
9. plastic pipe service life evaluating apparatus according to claim 1, it is characterised in that：
The temperature-control range of the temperature control box includes 20-26 DEG C.
10. plastic pipe service life evaluating apparatus according to claim 1, it is characterised in that：
The upper grip includes fixed part and rotation section；Fixed part upper end is connected to the output end of the driving device, described solid
Determine portion lower end be equipped with ship and resell on another market, the cup-like structure that the rotation section is the downwardly facing opening being made of roof and side enclosure wall, the top
Wall is rotatably connected at shipping and reselling on another market for the fixed part, and can be rotated relative to the fixed part；The side enclosure wall lower end is equipped with
Internal thread, the internal thread are configured for the external screw thread of sample upper end peripheral surface described in screw-thread fit；
The lower collet is opening up cup-like structure, and the lower collet is fixedly connected with the pedestal, and the lower collet
Aperture position is equipped with internal thread, the external screw thread of the peripheral surface of the lower end for sample described in screw-thread fit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721675476.0U CN207650042U (en) | 2017-12-04 | 2017-12-04 | Plastic pipe service life evaluating apparatus |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721675476.0U CN207650042U (en) | 2017-12-04 | 2017-12-04 | Plastic pipe service life evaluating apparatus |
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| CN207650042U true CN207650042U (en) | 2018-07-24 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107764671A (en) * | 2017-12-04 | 2018-03-06 | 广州特种承压设备检测研究院 | Plastic pipe life-span evaluating apparatus |
-
2017
- 2017-12-04 CN CN201721675476.0U patent/CN207650042U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107764671A (en) * | 2017-12-04 | 2018-03-06 | 广州特种承压设备检测研究院 | Plastic pipe life-span evaluating apparatus |
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