CN106706411A - Minitype centrifuge experimental apparatus oriented to three-dimensional printed geotechnical model and research method thereof - Google Patents
Minitype centrifuge experimental apparatus oriented to three-dimensional printed geotechnical model and research method thereof Download PDFInfo
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- CN106706411A CN106706411A CN201611016717.0A CN201611016717A CN106706411A CN 106706411 A CN106706411 A CN 106706411A CN 201611016717 A CN201611016717 A CN 201611016717A CN 106706411 A CN106706411 A CN 106706411A
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Abstract
The invention discloses a minitype centrifuge experimental apparatus oriented to a three-dimensional printed geotechnical model and a research method thereof. The minitype centrifuge experimental apparatus comprises a computer, a variable-frequency controller, an asynchronous motor and a centrifuge device, wherein the asynchronous motor is connected with the computer through the variable-frequency controller; the centrifuge device comprises a separate-type experiment cavity and a separate-type counterweight cavity which are formed on opposite inner walls of a rotating cylinder; the center of the rotating cylinder is provided with a rotating shaft; the rotating shaft is connected with a transmission shaft of the asynchronous motor through a conveying belt, so that the rotating shaft of the asynchronous motor drives the transmission shaft to rotate at a high speed, and a simulation experiment is performed on the simulated gravity field of the test model; the separate-type experiment cavity is internally provided with an image collection device. By virtue of a digital image correlation measurement technology, the minitype centrifuge experimental apparatus is capable of analyzing the collected images so as to obtain deformation damage data of the minitype centrifugal experiment model, furthermore verifying a numerical simulation method and realizing research on microstructure damage rules of geotechnical materials.
Description
Technical field
The present invention relates to simulating experiment technique field, more particularly to a kind of Minitype centrifugal towards 3 D-printing geotechnical model
Machine experimental provision and research method.
Background technology
In to the scientific research of Practical Project problem, it is often necessary to entered using the physical model for reducing according to a certain percentage
Row simulated test, therefrom discloses the inside essence and failure mechanism of research object, is desirably to obtain rational explanation, and engineering is made
It is correct to estimate judgement or select correct scheme.In Geotechnical Engineering, large-scale Rock And Soil destruction is mainly due to deadweight condition
What lower its internal stress field action was caused.If the bench model to Rock And Soil under normal gravity state carries out development test,
Because moulded dimension reduces the reduction for causing its internal stress, the precision and confidence level of experimental studies results can be substantially reduced.It is logical
Crossing artificial work increases the weight stress of test model, experimental model is reached the equal stress level of learning prototype as far as possible,
Geotechnical centrifuge application in test solves this problem well.According to centrifugal force field and gravitational field principle of equal value,
The experimental model for reducing n times is placed in ng times of centrifugal force field, promotes the ess-strain of model and prototype corresponding position to approach, become
Shape is similar, failure mechanism is identical, by reproducing the physical characteristic of prototype, for theoretical calculation and numerical simulation provide with a high credibility
Reference data.
When Frenchman E.phillips in 1869 is studied for the bridge across the English Channel, it is proposed that centrifuge
The General Principle of design, it is desirable to verified by centrifugal model test, but due to condition at that time, this is envisioned and is not carried out.Six
After more than ten years, compact centrifuge is applied to mine experiment and stability of slope problem by some scholars of the U.S. and the former Soviet Union respectively
Research in, so far centrifuge model test technique is gradually promoted in engineering research field.Later stage nineteen sixties,
The states such as Britain, the U.S., Japan, France, Germany, Denmark, Italy start to build geotechnical centrifuge, the promotion of high degree successively
Centrifuge modelling tests theory and technologies it is perfect.After the eighties, the state such as Japan, China, Singapore, India combines modern
Change manufacturing technology, built a collection of Novel centrifuge, a portion centrifuge starts gradually to develop to Large Copacity direction.
With the development of geotechnical centrifuge, the field of geotechnical centrifugal model test application covers underground retaining structure, soft soil foundation, soil
Geosynthetics reinforced retaining wall, offshore platform, tunnel excavation, frozen soil engineering, environment soil mechanics, blast analogue, earthquake and
All many-sides such as liquefaction simulation.
Because centrifugal acceleration changes with radius is centrifuged, the stress distribution of test model can be produced necessarily with prototype
Error, but this error can be gradually reduced with the increase of centrifugal basket arm lengths.On the other hand, the contracting of test model
Small scale n is smaller, i.e. the size of experimental model is bigger, closer to learning prototype, and the accuracy and confidence of experimental result is higher.
Large geotechnical centrifuge because be provided simultaneously with 2 points of the above, the stress state of reduction learning prototype that can be more complete and destruction
Mechanism and be subject to domestic and foreign scholars to favor, the current domestic upsurge Fang Xinwei Chinese mugworts for developing large geotechnical centrifuge.But, large-scale soil
The construction of work centrifuge, using and later maintenance need the input in a steady stream of fund and large quantities of experimenters to participate in, this and reality
Test required precision general small research not high to test and mismatch, cause the significant wastage of resource.At the same time, make with
The large scale model that large geotechnical centrifuge matches needs the more personnel of input and material, experimental model single use but
It is that fabrication cycle is long, cost is high.Therefore, the micro centrifuge matched with small test is built, lab space, pole can be saved
The reduction experimental cost of degree, shortening modelling and centrifugal test time, reduction experimental study personnel and material resources put into greatly.
Three-dimensional printing technology be it is a kind of by with can jointing material successively print and construct the rapid shaping of three-dimensional body
Technology, due to the advantage of the product of its repeatable multiple identical proterties of manufacture, is gradually paid attention to, at present by scientific experiment personnel
Apply in industrial design, military engineering, therapeutic treatment, scientific research, food manufacturing, mobile communication, building, Aero-Space etc.
Multiple fields.
Three-dimensional printing technology has great advantage compared to the manufacture of traditional experiment model：First, 3 D-printing conduct
A kind of rapid shaping technique shortens the model manufacturing cycle, and experimental model can be printed disposably in batch, high degree
Save personnel input；Secondly, printed by computer controls, modelling high precision, the reality complicated for contour structures
Testing model, internal structure needs to set the model of (such as precrack inside model), 3 D-printing model and traditional mould
Type manufacture is compared to the advantage having in essential technique；Thirdly, the model for being made by three-dimensional printing technology has good equal
One property, it is possible to reduce influence of other irrelevant factors to experimental result.Three-dimensional printing technology can be in rock by unique advantage
There is broader prospect in the future development of mechanics field.But, three-dimensional printing technology is because its defect also limit itself
Quick development.For rock mechanics, instrument, the cost of material cause that modelling is costly, it is difficult to beat three-dimensional
Print technology is widely used in rock mechanics field.Further, since moulded dimension is limited by printer size, is printed material
Material high cost, 3 D-printing is difficult to break through the bottleneck of itself in terms of large-scale model making.Therefore, by small-sized rock mechanics experiment
It is combined with three-dimensional printing technology, is the main expansion direction of country ground field scholar at present.
The content of the invention
It is applied to small-sized rock mechanics experiment it is an object of the invention to provide one kind and accurately can effectively obtains ground material
The micro centrifuge experimental provision towards 3 D-printing geotechnical model of material destruction characteristic and related data.
Rule are destroyed it is a further object of the present invention to provide a kind of model realized using above-mentioned micro centrifuge experimental provision
Rule research method.
Therefore, technical solution of the present invention is as follows：
A kind of micro centrifuge experimental provision towards 3 D-printing geotechnical model, including it is computer, frequency-variable controller, different
Step motor and centrifugal device；The centrifugal device and the asynchronous machine are arranged on a cushion cap；The asynchronous machine passes through institute
Frequency-variable controller is stated to be connected with the computer.
The centrifugal device includes separate type experiment cavity, separate type counterweight cavity and rotating cylinder；The rotating cylinder center
Rotary shaft is provided with, the rotary shaft is connected with the power transmission shaft of the asynchronous machine by conveyer belt, makes turning for the asynchronous machine
Moving axis drives the power transmission shaft high-speed rotation and drives rotating cylinder high-speed rotation in the horizontal direction.
The separate type experiment cavity and the separate type counterweight cavity are respectively provided with and are fixed on the interior of the rotating cylinder
On wall and offside set.
The separate type experiment cavity includes digital observation analysis room and the model locellus for housing experimental model, described
Model locellus is sleeved on the digital observation analysis room inner side and leads between the model locellus and the digital observation analysis room
Cross the rotating shaft set parallel to the rotating cylinder rotation direction to be flexibly connected, make the model locellus in the high speed of the rotating cylinder
Along 90 ° of axis of rotation under rotation；A dismountable digital observation analysis chamber cap is provided with the top of the digital observation analysis room
Body, digital observation analysis room lid inner side is provided with microcam and LED lamp source.
The separate type counterweight cavity includes counterweight cavity；The counterweight cavity outer shape and size and the experiment chamber
The outer shape of body (i.e. digital observation analysis room) and in the same size, and top is configured with opening the counterweight chamber lid for unloading；It is described
Multiple tracks interval and draw-in groove arranged in parallel are offered in counterweight cavity, several can be on demand placed in draw-in groove described in per pass and be matched somebody with somebody
Weight piece.
It is preferred that, one tubular protective cover is housed in the rotating cylinder outer sheath, it is equipped with the protective cover top side detachable lid
One lucite cover plate；The protective cover is fixed on the cushion cap.
It is preferred that, the microcam is arranged on digital observation analysis room lid inner side plate face center；The LED
Source is four, is separately positioned at four drift angles of digital observation analysis room lid inner side plate face.
It is preferred that, the vertical range of the microcam to the model locellus is 75mm.
It is preferred that, the image resolution ratio 720p of the microcam, its is per second can to gather 25 two field pictures；Described in each
The brightness of LED is 4w.
It is a kind of to realize that geotechnical model is destroyed using the micro centrifuge experimental provision towards 3 D-printing geotechnical model
Law study method, comprises the following steps：
The photo that S1, microcam will be collected is sent to computer；Wherein, microcam is per second can gather 25
Two field picture, i.e., carry out an IMAQ every 0.04s, multiple experimental models is got in experimentation and is deformed into destruction
Photo；
S2, all photos to collecting carry out image procossing with two photos of every continuous acquisition as one group：With previous
Photo is opened as benchmark, the identical monitoring point on continuous two photos is checked by pixel, is compared and tracing computation corresponding points
Correlation, determine the displacement of measurement position；
S3, by the change in displacement of the multiple monitoring points to being laid on experimental model carry out calculate obtain model destroy
Point, model deformation to the time cycle, each monitoring point of model of broken ring destruction sequentially, so as to obtain the change figurate number of whole model
According to.
It is preferred that, when 3 D-printing is carried out to experimental model, by the theoretical breakdown point and/or random set point of experimental model
Model monitoring point is classified as, and different colours mark is carried out to different monitoring points by three dimension color printing, be easy at successive image
During reason to different photos in identical monitoring point determination.
Compared with prior art, should be towards micro centrifuge experimental provision small volume, the quality of 3 D-printing geotechnical model
Gently, low cost, significantly reduces the input of fund, experimenter and material and mobile carrying, low to experimental site requirement；Profit
Geotechnical Engineering model is printed with three-dimensional printing technology can carry out reasonable scaled down by size, be applicable not only to all kinds of tools
There is the model of complicated inside and outside structure, effectively shorten the modelling cycle, simultaneously because the characteristics of its " miniature ", in learning prototype
During stress state under gravity, micro centrifuge rotating speed is higher than traditional geotechnical centrifuge, and model is convex by centripetal force
Aobvious, the comparatively speaking influence to experimental result such as model gravity, frictional force is more weakened, and reduces experimental error, and engineering is done
Go out and correctly estimate judgement, select correct processing scheme；It is compared with same experiments, micro centrifuge experimental model has
Good homogeneity, can avoid other irrelevant factors (such as crackle, hole, particle size) from tying experiment in experimentation
The influence of fruit；Collection picture is analyzed additionally by Digital-image correlation method technology obtains Minitype centrifugal experimental model
Deformation failure data, and be used to verify method for numerical simulation, the research to the microscopical structure failure law of rock-soil material is realized,
Notional result anticipation is given to damage -form of the learning prototype in body stress loading procedure.
Brief description of the drawings
Fig. 1 is the structural representation of the micro centrifuge experimental provision towards 3 D-printing geotechnical model of the invention；
Fig. 2 is that the structure of the rotating cylinder of the micro centrifuge experimental provision towards 3 D-printing geotechnical model of the invention is shown
It is intended to；
Fig. 3 is the separate type experiment cavity of the micro centrifuge experimental provision towards 3 D-printing geotechnical model of the invention
Structural representation；
Fig. 4 is the structure of the experiment cavity of the micro centrifuge experimental provision towards 3 D-printing geotechnical model of the invention
Schematic diagram；
Fig. 5 is the number of the experiment cavity of the micro centrifuge experimental provision towards 3 D-printing geotechnical model of the invention
The inside structure schematic diagram of observation analysis chamber cap body；
Fig. 6 is the vertical view of the experiment cavity of the micro centrifuge experimental provision towards 3 D-printing geotechnical model of the invention
Structural representation；
Fig. 7 is the separate type counterweight cavity of the micro centrifuge experimental provision towards 3 D-printing geotechnical model of the invention
Structural representation；
Fig. 8 is the vertical view of the counterweight cavity of the micro centrifuge experimental provision towards 3 D-printing geotechnical model of the invention
Structural representation.
Specific embodiment
Below in conjunction with the accompanying drawings and specific embodiment the present invention is described further, but following embodiments are absolutely not to this hair
It is bright to have any limitation.
As shown in figure 1, computer 1, frequency conversion should be included towards the micro centrifuge experimental provision of 3 D-printing geotechnical model
Controller 2, asynchronous machine 6 and centrifugal device；
The centrifugal device and the asynchronous machine 6 are arranged on a cushion cap 3；
The cushion cap 3 include horizontally disposed supporting plate and be distributed on the supporting plate bottom surface for supporting the branch
The bearing 4 of fagging；
The asynchronous machine 6 is used to provide the rotational energy of centrifuge；A power transmission shaft is provided with the asynchronous machine 6
601, the bottom of the power transmission shaft 601 is stretched out from the bottom surface of the asynchronous machine 6 and is opened up on relevant position through in the supporting plate
Through hole, the bottom of the power transmission shaft 601 is extend out to the lower section of the supporting plate；
The asynchronous machine 6 is connected by the frequency-variable controller 2 with the computer 1, and this is due to the asynchronous electricity
The rotating speed of machine 6 is influenceed by supply and AC frequency.The alternating current of such as China is 50Hz, to control the rotating speed of centrifuge to be accomplished by
Use frequency-variable controller.Frequency-variable controller can reach the effective regulation to rotating speed, improve the accuracy of experiment.By frequency conversion
The frequency of the alternating current of controller regulation input asynchronous machine, it is final to realize so as to reach the purpose of control Rotational Speed of Asynchronous Motor
The control of the centrifugal force being applied to centrifuge on sample.
The centrifugal device includes separate type experiment cavity 7, separate type counterweight cavity 8, lucite cover plate 9, protective cover
10 and rotating cylinder 11；Wherein：
The protective cover 10 is the tube structure of a both ends open, and it is fixed in the supporting plate；The lucite
The lid of cover plate 9 closes the top open part of the protective cover 10 on the top surface of the protective cover 10；
As shown in Fig. 2 the rotating cylinder 11 is an open-topped tubular construction, a rotation is provided with its bottom centre
Axle 12, the through hole on the bottom surface of the rotating cylinder 11 and the supporting plate relevant position of the rotary shaft 12, makes the rotary shaft
12 bottoms extend out to the lower section of the supporting plate；The power transmission shaft 601 and the rotary shaft 12 are by being fixed on the transmission of bottom
Band 5 is connected, and the rotary shaft 12 is driven the high-speed rotation of the power transmission shaft 601 and is driven the rotating cylinder 11 high in the horizontal direction
Speed is rotated；The vertical tremor that the tubular rotating cylinder can reduce cavity in experiment rocks, and reduces dynamic error, improves the steady of device
It is qualitative.
The rotating cylinder 11 is arranged in the protective cover 10, and the protective cover 10 and the rotating cylinder 11 axis
On same axis；Four uniform mounting holes 1001, four institutes are respectively offered on the offside side wall of the rotating cylinder 11
Line constitutes a rhombus successively to state mounting hole 1001；
As shown in figure 3, the separate type experiment cavity 7 fixes tile 701 and experiment cavity 702 by integrally formed first
Constitute；The first fixation tile 701 is one piece of radian arc adaptable with the inwall radian of the rotating cylinder 11, and
Offered on the arc with one-to-one four connecting holes on the side wall of the rotating cylinder 11, make it is described first fix tile
701 are fixed on the inwall of the rotating cylinder 11 by the screw being inserted into the connecting hole and the mounting hole 1001；
As shown in Figure 4, Figure 5 and Figure 6, the experiment cavity 702 includes digital observation analysis room 7021 and is sleeved on described
Model locellus 7022 inside digital observation analysis room 7021；One is each provided with the offside side wall of the model locellus 7022
Rotating shaft 7026, makes to be flexibly connected by rotating shaft 7026 between the digital observation analysis room 7021 and the model locellus 7022,
And two rotating shafts 7026 positioned at offside are located on the same line, axial direction and the rotating cylinder of the rotating shaft 7026 turn
Dynamic direction is parallel；Specifically, the digital observation analysis room 7021 and the model locellus 7022 are open-topped hollow
Square framed-tube structure, the height of the height of the model locellus 7022 less than the digital observation analysis room 7021；Such as Fig. 5 institutes
Show, the top of the digital observation analysis room 7021 is provided with a digital observation analysis room lid 7023, the digital observation
The inner side plate face center of analysis room's lid 7023 sets and is fixed with the microcam 7024 that an inside is provided with battery, in institute
Four self-powered LEDs are set and are fixed with four drift angles for stating the inner side plate face of digital observation analysis room lid 7023
7025；Digital observation analysis room lid 7023 is by being fixed on the screw on four drift angles with the digital observation analysis room
7021 detachably connected fixations；
Wherein, the microcam 7024 is using the permanent minisize pick-up head X9 (wifi editions) for thinking peace (HOSION) production
32g cards, video camera size is 62 × 35 × 15mm, per second to gather 25 two field pictures, image resolution ratio 720p；Described in each
The brightness 4w of LED 7025；The microcam 7024 to the vertical range of the model locellus 7022 is 50~90mm；
The model locellus 7022 is used to house the experimental model of 3 D-printing, wherein, the four of the model locellus 7022
Side wall neighbouring with the inwall of the rotating cylinder 11 and positioned at offside is made of lucite in individual side wall；When the rotating cylinder 11
During high-speed rotation, with the gradually increase of centrifugal force field, the digital observation analysis room 7021 of the experiment cavity 702 turns therewith
Dynamic, the model locellus 7022 drives experimental model to rotate 90 °, the side wall being made of lucite under the effect of rotating shaft 7026
Turned to positioned at the medial surface offside of digital observation analysis room lid 7023 by 90 °, both met microcam shooting
Need, model is prevented from again and is thrown away to image mechanism into destruction；
The separate type experiment cavity 7 and the separate type counterweight cavity 8 are located on the offside inwall of the rotating cylinder 11；
The separate type counterweight cavity 8 is used to balance the out-of-balance force that the separate type experiment cavity 7 brings；
As shown in fig. 7, the separate type counterweight cavity 8 includes that integrally formed second fixes tile 801 and counterweight cavity
802；The second fixation tile 801 is one piece of radian arc adaptable with the inwall radian of the rotating cylinder 11, and
Offered on the arc with one-to-one four connecting holes on the side wall of the rotating cylinder 11, make it is described second fix tile
801 are fixed on the inwall of the rotating cylinder 11 by the screw being inserted into the connecting hole and the mounting hole 1001；
As shown in figure 8, the outer shape and size of the counterweight cavity 802 and experiment cavity 702 (the i.e. digital observation
Analysis room) 7021 outer shape and in the same size, the top cover of counterweight cavity 802 is equipped with counterweight chamber lid, the counterweight
Chamber lid is opened with the counterweight cavity 802 by the screw being fixed on four drift angles and is releasably connected；The counterweight chamber
Multiple tracks interval and draw-in groove 803 arranged in parallel are offered in body 802, can on demand place some in draw-in groove 803 described in per pass
Individual weight stack 804, by increasing and decreasing the mechanical balance that combined counterbalance piece realizes centrifuge in draw-in groove 803.
3 D-printing shortens the modelling time as a kind of rapid shaping technique, and experimental model can be disposable
Print in batch, so the micro centrifuge experimental period towards 3 D-printing geotechnical model is far smaller than conventional centrifuge model
Experiment.Therefore, learning prototype can be passed through three towards the micro centrifuge experimental provision of 3 D-printing geotechnical model using this
Dimension printing technique is printed as being contracted to a certain proportion of miniature Geotechnical Engineering model, then is entered by the experimental provision simulated gravity
Row simulated experiment, is that engineering construction does so as to obtain the inside essence and failure mechanism of the medium-and-large-sized Rock And Soil destruction of Geotechnical Engineering
Go out correct estimating to judge or Scheme Choice.
Using three-dimensional printer print experimental model when, it is necessary first to computer three-dimensional drawing software (such as
AutoCAD experimental model is drawn in), generation three-dimensional printer identified documentation (such as stl files) is then transferred the file to
In the subsidiary software of printer.The ratio of powder and glue is set in a computer, and printer is started working.Below with Tianjin
It is introduced as a example by the three-dimensional printer that university's ground is configured：Printer cavity size is 254 × 381 × 203mm, model examination
Sample can be printed disposably in the range of cavity size.In order to reduce the time-write interval, setting experimental model is arranged in cavity
Bottom position, the direction of printing is from bottom to top.Printing starting stage, printer first lays several layers of powder the bottom of as in cavity bottom
Plate, in print procedure, printer is incremented by until printing terminates upwards with every layer of thickness of laying 0.1mm powder.Although three-dimensional is beaten
During print, multiple experimental models are printed in batch and expends the time than individually one model of printing, but compared to by multiple models
Print respectively and still saved the plenty of time.After the completion of printing, it is small that experimental model needs to stay in printer cavity at least one half
Shi Jinhang dries.After model takes out, the powder of its attachment can be cleared up by air cannon, not utilized in printer cavity
Powder can be used the retracting device that carries of printer to be reclaimed.After the cleaning of model surface powder, then by special liquid
Infiltration solidification, can be used as preferable Rock Mechanics Test research material after drying.
Compared with traditional experiment model, computer control three-dimensional printer printer model is crossed, it is multiple for outward appearance and internal structure
Miscellaneous model is easy to can be achieved with, and is adapted to the learning prototype of different structure；Additionally, using three-dimensional printer impression block
Type, modelling high precision, parameter is accurate, can reach the requirement of theoretical calculation, engineering is made and correctly estimate judgement, choosing
Select correct processing scheme.Wherein, during concrete practice, additionally it is possible to right using the colour print function of three-dimensional printer
The monitoring point of experimental model is marked.A printer model sample is such as given, printer can be in its surface monitoring point periphery
Circle of the printing with conspicuous color.This function is for the data acquisition of experimental model that deforms and destroy very just
Profit.
In experimentation, experimental model is placed in model locellus 7022, when model locellus 7022 is in the rotating cylinder
When under 11 rotation drive along axis of rotation to horizontal direction, experimental model is in a centrifugal force field, former with analog study
Type suffered stress in gravitational field.Due to the likelihood ratio principle in centrifuge test according to centrifugal model, n times of size reduction
Experimental model is placed in ng times of centrifugal force field, and the stress that model is subject to because of centrifugal force field is with learning prototype in gravitational field
Suffered stress is equivalent.Although experimental model is also by the Action of Gravity Field of 1 × g, because moulded dimension is smaller, its gravity institute band
The ess-strain for coming can be ignored substantially.
Now, model can be reduced to by acceleration：
A=ng=w2r
In formula, w is centrifuge angular velocity of rotation, and r is the effective radius of turn of experimental model.
Gravity acceleration g is definite value；In micro centrifuge, effective radius of turn r is definite value；When the diminution of experimental model
When ratio n determines, equation ng=w is made by the rotational angular velocity w for adjusting centrifuge2R sets up.It is real i.e. under this angular velocity of rotation
The stress for testing generation of stress of the model because of centrifugal force field generation with prototype in gravitational field is equivalent.
Because experimental model size is small, in order to reach learning prototype stress state under gravity, micro centrifuge
Rotating speed is higher than traditional geotechnical centrifuge, and model is highlighted by centripetal force, and comparatively speaking model gravity, frictional force etc. are to experiment
The influence of result is more weakened, and reduces experimental error；Construction use and later maintenance relative to super-magnum centrifuge need source
Source is constantly injected capital into and personnel, micro centrifuge experimental provision small volume, light weight, the low cost, is significantly reduced
The input of fund, experimenter and material.
During simulated experiment, microcam carries out whole sequential image acquisition to experimental model, obtains experiment mould
The type process that gradually model deformation is destroyed in whole experiment process, to provide data, and by " digital picture correlative measurement
Amount technology " (DIC) is analyzed for the data of deformation failure.Because image collecting device and experimental model do centrifugation fortune together
Dynamic, geo-stationary, compares with traditional data acquisition mode, effectively reduces in data transmission procedure because centrifugal motion logarithm
According to the interference of transmission.
The specific method of later image treatment, comprises the following steps：
The photo that S1, microcam 7024 will be collected is sent to computer 1；Wherein, microcam 7024 is per second
25 two field pictures can be gathered, i.e., carries out an IMAQ every 0.04s, the change of multiple experimental models is got in experimentation
The photo that shape is extremely destroyed；
S2, all photos to collecting carry out image procossing with two photos of every continuous acquisition as one group：With previous
Photo is opened as benchmark, the identical monitoring point on continuous two photos is checked by pixel, is compared and tracing computation corresponding points
Correlation, determine the displacement of measurement position；
S3, by the change in displacement of the multiple monitoring points to being laid on experimental model carry out calculate obtain model destroy
Point, model deformation to the time cycle, each monitoring point of model of broken ring destruction sequentially, so as to obtain the change figurate number of whole model
According to.
Wherein, before centrefuge experiment, when 3 D-printing is carried out to experimental model, by the theoretical breakdown point of experimental model and/
Or random set point is classified as model monitoring point, and different colours mark is carried out to different monitoring points by three dimension color printing, just
In successive image processing procedure to different photos in identical monitoring point determination.
Claims (7)
1. a kind of micro centrifuge experimental provision towards 3 D-printing geotechnical model, it is characterised in that including computer (1),
Frequency-variable controller (2), asynchronous machine (6) and centrifugal device；The centrifugal device and the asynchronous machine (6) are arranged on a cushion cap
(3) on；The asynchronous machine (6) is connected by the frequency-variable controller (2) with the computer (1)；
The centrifugal device includes that separate type tests cavity (7), separate type counterweight cavity (8) and rotating cylinder (11)；The rotation
Cylinder (11) center is provided with rotary shaft (12), and the power transmission shaft (601) of the rotary shaft (12) and the asynchronous machine (6) is by transmission
Band (5) connection, makes the rotary shaft (12) of the asynchronous machine (6) drive power transmission shaft (601) high-speed rotation and drive described
Rotating cylinder (11) high-speed rotation in the horizontal direction；
The separate type tests cavity (7) and the separate type counterweight cavity (8) is respectively provided with and is fixed on the rotating cylinder
(11) on inwall and offside set；
The separate type tests model locellus of the cavity (7) including digital observation analysis room (7021) and for housing experimental model
(7022), the model locellus (7022) is sleeved on digital observation analysis room (7021) inner side and the model locellus
(7022) by turning for being set parallel to the rotating cylinder (11) rotation direction and the digital observation analysis room (7021) between
Axle (7026) is flexibly connected, and makes the model locellus (7022) under the high-speed rotation of the rotating cylinder (11) along axis of rotation
90°；Dismountable digital observation analysis room lid (7023), institute are provided with the top of the digital observation analysis room (7021)
State digital observation analysis room lid (7023) inner side and be provided with microcam (7024) and LED lamp source (7025)；
The separate type counterweight cavity (8) includes counterweight cavity (802)；Counterweight cavity (802) appearance and size and the number
Code observation analysis room (7021) is consistent, and top is configured with opening the counterweight chamber lid for unloading；Opened up in the counterweight cavity (802)
There is multiple tracks to be spaced and draw-in groove (803) arranged in parallel, several weight stacks can be on demand placed in draw-in groove (803) described in per pass
(804)。
2. the micro centrifuge experimental provision towards 3 D-printing geotechnical model according to claim 1, it is characterised in that
One tubular protective cover (10) is housed in the rotating cylinder (11) outer sheath, one is equipped with the protective cover (10) top side detachable lid
Lucite cover plate (9)；The protective cover (10) is fixed on the cushion cap (3).
3. the micro centrifuge experimental provision towards 3 D-printing geotechnical model according to claim 1, it is characterised in that
The microcam (7024) is arranged on digital observation analysis room lid (7023) inner side plate face center；The LED
Source (7025) is four, is separately positioned at four drift angles of digital observation analysis room lid (7023) inner side plate face.
4. the micro centrifuge experimental provision towards 3 D-printing geotechnical model according to claim 3, it is characterised in that
The microcam (7024) to the vertical range of the model locellus (7022) is 75mm.
5. the micro centrifuge experimental provision towards 3 D-printing geotechnical model according to claim 3, it is characterised in that
The image resolution ratio 720p of the microcam (7024), its is per second can to gather 25 two field pictures；Each described LED
(7025) brightness is 4w.
6. it is a kind of using according to any one of Claims 1 to 5 claim towards 3 D-printing geotechnical model micro-
Type centrifuge experiment device realizes geotechnical model failure law research method, it is characterised in that comprise the following steps：
The photo that S1, microcam (7024) will be collected is sent to computer (1)；Wherein, microcam (7024) is every
Second can gather 25 two field pictures, i.e., carry out an IMAQ every 0.04s, and multiple experimental models are got in experimentation
It is deformed into the photo of destruction；
S2, all photos to collecting carry out image procossing with two photos of every continuous acquisition as one group：With previous Zhang Zhao
Piece is used as benchmark, the phase for passing through pixel check, comparison and tracing computation corresponding points to the identical monitoring point on continuous two photos
Guan Xing, determines the displacement of measurement position；
S3, by the change in displacement of the multiple monitoring points to being laid on experimental model carry out calculate obtain model destroy starting point,
Model deformation to the time cycle, each monitoring point of model of broken ring destruction sequentially, so as to obtain the deformation data of whole model.
7. geotechnical model failure law research method according to claim 6, it is characterised in that carried out to experimental model
During 3 D-printing, the theoretical breakdown point and/or random set point of experimental model are classified as model monitoring point, and by three-dimensional colour
Printing carries out different colours mark to different monitoring points, the identical monitoring in being easy in successive image processing procedure to different photos
The determination of point.
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