阅读说明：本技术 一种基于3d打印制备光纤光栅模型土工格栅的装置及方法 (Device and method for preparing fiber grating model geogrid based on 3D printing ) 是由 李从安 胡波 李波 童军 宋诚 甘旭东 谢学伦 于 2021-04-08 设计创作，主要内容包括：本发明提供一种基于3D打印制备光纤光栅模型土工格栅的装置及方法,该装置包括计算机系统和模型土工格栅打印设备,所述模型土工格栅打印设备包括打印机机架、安装于打印机机架的土工格栅原料供应组件、喷头移动组件、设于土工格栅原料供应组件端头的喷头、设于喷头下方的打印平台、喷头移动组件。本发明通过3D打印技术将光纤光栅封装于模型土工格栅内部,解决了加筋土结构模型试验中筋材应力的测量问题,实现了模型土工材料的变形及内力精确测量。(The invention provides a device and a method for preparing a fiber grating model geogrid based on 3D printing. According to the invention, the fiber bragg grating is packaged in the model geogrid by a 3D printing technology, so that the problem of measurement of the stress of the reinforced material in a reinforced soil structure model test is solved, and the accurate measurement of the deformation and the internal force of the model geogrid is realized.)

1. The utility model provides a device based on 3D prints preparation fiber grating model geogrid which characterized in that: the model geogrid printing equipment comprises a printer frame, a geogrid raw material supply assembly, a spray head moving assembly, a spray head, a printing platform and a spray head moving assembly, wherein the geogrid raw material supply assembly is installed on the printer frame;

the geogrid raw material supply assembly is used for providing model geogrid raw materials;

the spray head is used for spraying the geogrid raw material provided by the geogrid raw material supply assembly;

the printing platform is used for receiving geogrid raw materials sprayed by the spray head to form a model geogrid;

the spray head moving assembly is used for driving the spray head to move in the X-axis direction and the Z-axis direction under the control of a computer system;

the printing platform moving assembly is used for driving the printing platform to move in the Y-axis direction under the control of a computer system;

and the computer system is used for designing a three-dimensional model of the model geogrid in advance, and controlling the spray head moving assembly and the spray head moving assembly to adjust the relative height and position of the spray head and the printing platform according to the three-dimensional model.

2. The apparatus for preparing a fiber grating model geogrid based on 3D printing according to claim 1, wherein: the geogrid raw material supply assembly comprises a storage tank, a conveying pipe and a slurry pump, wherein the storage tank is fixed on the printer frame and used for containing the geogrid raw materials of the model; the outlet of the stock chest is connected with a slurry pump through a delivery pipe, and a spray head is connected below the slurry pump.

3. The apparatus for preparing a fiber grating model geogrid based on 3D printing according to claim 2, wherein: the slurry pump is provided with a heating device, and the heating device is used for outputting the heated geogrid raw materials.

4. The apparatus for preparing a fiber grating model geogrid based on 3D printing according to claim 1, wherein: the sprayer moving assembly comprises an X-axis motor, an X-axis sliding rail, a Z-axis motor and a Z-axis sliding rail, the upper end and the lower end of each Z-axis sliding rail are respectively fixed on the printer frame, the two ends of each X-axis sliding rail are fixed on the Z-axis moving part of each Z-axis sliding rail, the Z-axis motor drives the Z-axis moving part to move up and down along the Z-axis sliding rails, and the X-axis sliding rails move along with the Z-axis moving part moving up and down on the Z-axis sliding rails.

5. The apparatus for preparing a fiber grating model geogrid based on 3D printing according to claim 4, wherein: the printing platform moving assembly comprises a Y-axis motor and a Y-axis sliding rail, the Y-axis sliding rail is fixed at the lower part of the printer frame, the printing platform is fixed on a support of the Y-axis sliding rail, the support is driven by the Y-axis motor to move back and forth along the Y-axis sliding rail, and then the printing platform is driven to move back and forth along the Y-axis sliding rail.

6. The apparatus for preparing a fiber grating model geogrid based on 3D printing according to claim 5, wherein: the nozzle is fixed on the X-axis sliding rail, is controlled by the X-axis motor to move left and right along the X-axis sliding rail and moves up and down along with the control of the Z-axis motor, and the printing platform is controlled by the printing platform moving assembly to move back and forth along the Y axis so as to realize a 3D printing effect.

7. A method for preparing a fiber grating model geogrid based on 3D printing is characterized by comprising the following steps: which is carried out with the device according to any one of claims 1 to 6, the method comprising the steps of:

(1) designing a three-dimensional model of a model geogrid and a laying mode in a soil body by utilizing three-dimensional drawing software installed in a computer system;

(2) loading raw materials of the geogrid into a storage tank in a raw material supply assembly of the worker grid, opening a material conveying pump, conveying the raw materials of the geogrid to a spray head through a material conveying pipe, adjusting the discharging speed of the storage tank, opening a heating device in the material conveying pump of the raw material supply assembly of the worker grid, and adjusting the melting temperature of the raw materials;

(3) controlling a nozzle moving assembly and a nozzle moving assembly to adjust the relative height and position of a nozzle and a printing platform according to a preset three-dimensional model of a model geogrid in a computer system, and starting to print the model geogrid by using model geogrid printing equipment;

(4) embedding a grid: in the process of printing the model geogrid, the geogrid is divided into an upper layer and a lower layer to be printed, the lower layer of the model geogrid is printed, a groove is reserved during printing, a fiber grating sensor is implanted into the reserved groove when the temperature of the lower layer of the model geogrid is reduced to 40-80 ℃, after the lower layer of the model geogrid is buried and finished, the upper layer of the model geogrid is printed, after the printing is finished, the pressure of the upper layer of the model geogrid is applied to the mold geogrid which is subjected to encapsulation and is 2-35 kpa, the model geogrid is fully bonded with the fiber grating sensor, and the internal embedding process of the fiber grating is finished.

8. The method for preparing a fiber grating model geogrid based on 3D printing according to claim 7, wherein the method comprises the following steps: in the step (2), the discharging speed of the storage tank is adjusted to be 360-720 r/min, and the melting temperature of the raw material is adjusted to be 220-480 ℃.

9. The method for preparing a fiber grating model geogrid based on 3D printing according to claim 7, wherein the method comprises the following steps: the raw material of the geogrid is one or a mixture of Polyethylene (PE), Polyester (PET), Polyamide (PER), polypropylene (PP), polyvinyl chloride (PVC), Chlorinated Polyethylene (CPE) and polystyrene (EPS).

10. The method for preparing a fiber grating model geogrid based on 3D printing according to claim 7, wherein the method comprises the following steps: further comprising the steps of:

(5) and (3) model test: after the model geogrid is printed, the model geogrid is embedded in soil or a gravel layer, the model geogrid is horizontally paved up and down according to a certain distance, the fiber grating sensor is connected to the fiber grating acquisition system, relevant model tests are carried out, and the internal force and the strain of the model geogrid under the action of external load are monitored.

Technical Field

The invention relates to the field of geotechnical engineering model tests, in particular to a device and a method for preparing a fiber grating model geogrid based on 3D printing.

Background

Geosynthetics are widely used in geotechnical engineering because of their advantages of high tensile strength, strong adaptability to deformation, low cost, etc. The reinforced earth structure is formed by embedding geosynthetic materials, such as geomembrane, geogrid, geocell and the like, into a soil body, and the mode of reinforcing the earth body is performed, so that the overall stability of the reinforced structure is improved, and the deformation effect is reduced.

In the design process of the existing reinforced soil structure, theoretical research usually lags behind engineering practice, so that engineering design is easy to be conserved, a great number of cases of failure and failure exist, the reason for analyzing and summarizing after the fact is different, and an engineering designer is more conservative. The essential reason is that the mechanism of the reinforced earth is not known. Because the reinforcement belongs to flexible materials, the monitoring difficulty is high when the reinforcement acts on the soil body, and the stress distribution of the reinforcement in the soil body is an important basis for recognizing the reinforcement mechanism.

Limited by the size of a prototype, the development of a full-scale model is long in construction period, large in construction investment and multiple in uncontrollable factors of a project. In this respect, model testing highlights its unique advantages. Compared with the prototype test, the model test has short test period and low cost, and different test parameters can be researched by adopting a single variable method. Therefore, the model test is an important means for researching the reinforcement mechanism, and the measurement of the reinforcement stress of the model test becomes the key point for the success of the model test.

The Chinese invention patent 'method for measuring deformation and stress of geogrid by using fiber grating' (application number: 201010237688.7) adopts structural adhesive and bundling mode to connect strain sensing optical fiber with warp grating or weft grating of the geogrid to be measured to measure deformation and internal force of reinforcement;

the invention relates to a geogrid strain gauge auxiliary pasting device and an operation method thereof (application number: 201710396946.8). The invention provides a convenient strain gauge pasting device, which measures the deformation of a rib material by pasting a strain gauge on the surface of a geogrid;

the invention relates to a geogrid strain measuring device and a geogrid strain measuring method in a model test (application number: 201510627033.3), which are characterized in that stainless steel strings are bound with a model geogrid, and strain of the geogrid is measured by a displacement meter connected with the stainless steel strings;

the invention patent of China 'a geogrid strain testing device and a testing method thereof' (application number: 201010124517.3) tests the geogrid strain by utilizing the tension sensitivity of a conductive rubber composite material, and the strain of the geogrid can be obtained by testing the resistance change;

the Chinese invention patent 'a sensing type geogrid material and a structure thereof' (application number: 201510814524.9) provides a manufacturing method of a sensing type geogrid with high strength and high friction resistance, wherein the resistance change of the grid is detected by utilizing the tension sensitive effect of a conductive polymer composite material to obtain the deformation of the grid and a reinforcing body;

according to the invention patent of China, namely the fiber bragg grating composite polyester geogrid and the preparation method thereof (application number: 201310434187.1), the fiber bragg grating, the composite reinforced identification yarns, the warp yarns and the weft yarns form a stable composite structure between layers, and the fiber bragg grating composite polyester geogrid is prepared through polymer coating treatment to measure the deformation of the geogrid.

The existing technical scheme mainly aims at the original geogrid, and the grating, the strain gauge or the steel string are mostly fixed on the surface of the geogrid at the same time, the binding type error is large, and the error is large due to the influence of the interaction of the rib-soil interface.

The inventor of the present application has found through research in the process of implementing the present invention that: with the gradual maturity of the optical fiber conduction technology and the 3D printing technology, the prototype grid material is adopted, the 3D printer is used for printing the model grid, and the fiber bragg grating is packaged in the model grid, so that not only can the interaction between the ribs and the soil in the prototype reinforced soil structure be correctly simulated, but also the internal force of the model ribs can be accurately measured, and an important promoting effect is provided for optimizing the design of the reinforced soil structure. Therefore, aiming at the defects and shortcomings of the existing measurement technology for strain of the rib material of the geosynthetic material of the model, the technology for efficiently printing, completely packaging and accurately measuring deformation and internal force of the geogrid of the model is developed by utilizing the 3D printing technology, and the method has important theoretical and application values.

Disclosure of Invention

The invention aims to overcome the defects and shortcomings and provides a device and a method for preparing a fiber grating model geogrid based on 3D printing.

In order to achieve the purpose, the invention provides a device for preparing a fiber grating model geogrid based on 3D printing, which comprises a computer system and model geogrid printing equipment, wherein the model geogrid printing equipment comprises a printer frame, a geogrid raw material supply assembly, a spray head moving assembly, a spray head arranged at the end of the geogrid raw material supply assembly, a printing platform arranged below the spray head and a spray head moving assembly, wherein the geogrid raw material supply assembly is arranged on the printer frame;

the geogrid raw material supply assembly is used for providing model geogrid raw materials;

the spray head is used for spraying the geogrid raw material provided by the geogrid raw material supply assembly;

the printing platform is used for receiving geogrid raw materials sprayed by the spray head to form a model geogrid;

the spray head moving assembly is used for driving the spray head to move in the X-axis direction and the Z-axis direction under the control of a computer system;

the printing platform moving assembly is used for driving the printing platform to move in the Y-axis direction under the control of a computer system;

and the computer system is used for designing a three-dimensional model of the model geogrid in advance, and controlling the spray head moving assembly and the spray head moving assembly to adjust the relative height and position of the spray head and the printing platform according to the three-dimensional model.

Further, the geogrid raw material supply assembly comprises a storage tank, a conveying pipe and a slurry pump, wherein the storage tank is fixed on the printer frame and used for containing the geogrid raw materials of the model; the outlet of the stock chest is connected with a slurry pump through a delivery pipe, and a spray head is connected below the slurry pump.

Further, the slurry pump is provided with a heating device, and the heating device is used for outputting the heated geogrid raw materials.

Furthermore, the sprayer moving assembly comprises an X-axis motor, an X-axis sliding rail, a Z-axis motor and a Z-axis sliding rail, the upper end and the lower end of each Z-axis sliding rail are respectively fixed on the printer frame, the two ends of each X-axis sliding rail are fixed on the Z-axis moving part of each Z-axis sliding rail, the Z-axis motor drives the Z-axis moving part to move up and down along the Z-axis sliding rails, and the X-axis sliding rails move along with the up and down movement of the Z-axis moving parts on the Z-axis sliding rails.

Furthermore, the printing platform moving assembly comprises a Y-axis motor and a Y-axis sliding rail, the Y-axis sliding rail is fixed at the lower part of the printer frame, the printing platform is fixed on a support of the Y-axis sliding rail, and the Y-axis motor drives the support to move back and forth along the Y-axis sliding rail so as to drive the printing platform to move back and forth along the Y-axis sliding rail.

Furthermore, the nozzle is fixed on the X-axis sliding rail, is controlled by the X-axis motor to move left and right along the X-axis sliding rail and moves up and down along with the control of the Z-axis motor, and the printing platform is controlled by the printing platform moving assembly to move back and forth along the Y axis so as to realize a 3D printing effect.

A method for preparing a fiber grating model geogrid based on 3D printing is carried out by adopting the device, and the method comprises the following steps:

(1) designing a three-dimensional model of a model geogrid and a laying mode in a soil body by utilizing three-dimensional drawing software installed in a computer system;

(2) loading raw materials of the geogrid into a storage tank in a raw material supply assembly of the worker grid, opening a material conveying pump, conveying the raw materials of the geogrid to a spray head through a material conveying pipe, adjusting the discharging speed of the storage tank, opening a heating device in the material conveying pump of the raw material supply assembly of the worker grid, and adjusting the melting temperature of the raw materials;

(3) controlling a nozzle moving assembly and a nozzle moving assembly to adjust the relative height and position of a nozzle and a printing platform according to a preset three-dimensional model of a model geogrid in a computer system, and starting to print the model geogrid by using model geogrid printing equipment;

(4) embedding a grid: in the process of printing the model geogrid, the geogrid is divided into an upper layer and a lower layer to be printed, the lower layer of the model geogrid is printed, a groove is reserved during printing, a fiber grating sensor is implanted into the reserved groove when the temperature of the lower layer of the model geogrid is reduced to 40-80 ℃, after the lower layer of the model geogrid is buried and finished, the upper layer of the model geogrid is printed, after the printing is finished, the pressure of the upper layer of the model geogrid is applied to the mold geogrid which is subjected to encapsulation and is 2-35 kpa, the model geogrid is fully bonded with the fiber grating sensor, and the internal embedding process of the fiber grating is finished.

Further, in the step (2), the discharging speed of the storage tank is adjusted to be 360-720 r/min, and the melting temperature of the raw material is adjusted to be 220-480 ℃.

Further, the raw material of the geogrid is one or a mixture of Polyethylene (PE), Polyester (PET), Polyamide (PER), polypropylene (PP), polyvinyl chloride (PVC), Chlorinated Polyethylene (CPE) and polystyrene (EPS).

Further, the method also comprises the following steps:

(5) and (3) model test: after the model geogrid is printed, the model geogrid is embedded in soil or a gravel layer, the model geogrid is horizontally paved up and down according to a certain distance, the fiber grating sensor is connected to the fiber grating acquisition system, relevant model tests are carried out, and the internal force and the strain of the model geogrid under the action of external load are monitored.

The invention has the following advantages:

1. the 3D printing technology is adopted, the limitation of the shape of the model geogrid is avoided, geogrid raw materials are adopted, and the printed model geogrid is highly similar to the tensile strength, the elongation and the reinforced soil interface friction coefficient of a prototype geogrid;

2. the fiber bragg grating can be completely packaged in the grating in the printing process of the model grating by adopting a 3D printing technology, the bonding performance of the grating and the fiber bragg grating is excellent, and meanwhile, the contact characteristic of the reinforced soil interface is not influenced;

3. the fiber bragg grating packaged in the geogrid of the model is used for measuring the deformation and the internal force of the rib in the test process, so that the measurement precision is high and the error is small.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of an apparatus for manufacturing a fiber grating model geogrid based on 3D printing according to the present invention;

FIG. 2 is a schematic structural diagram of a fiber grating collection system according to the present invention;

fig. 3 is a schematic view of a bi-directional geogrid printed using the present invention;

fig. 4 is a schematic view of a three-way geogrid printed using the present invention;

fig. 5 is a schematic view of a unidirectional geogrid printed using the present invention.

In the figure: 1-printer frame, 2-print platform, 3-stock chest, 4-conveying pipeline, 5-X axle motor, 6-Z axle slide rail, 7-Y axle motor, 8-Y axle slide rail, 9-Z axle motor, 10-X axle slide rail, 11-stuff pump, 12-shower nozzle, 13-model geogrid, 14-fiber grating sensor, 15-computer system, 16-fiber data line, 17-fiber grating collection system, 18-two-way grid, 19-three-way grid, 20-one-way grid.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Referring to fig. 1, one embodiment of the apparatus for manufacturing a fiber grating model geogrid based on 3D printing according to the present invention includes a computer system 15 and a model geogrid printing device,

the model geogrid printing equipment comprises a printer frame 1, a geogrid raw material supply assembly, a spray head moving assembly, a spray head 12, a printing platform 2 and a spray head moving assembly, wherein the geogrid raw material supply assembly is installed on the printer frame 1;

the geogrid raw material supply assembly is used for providing a model geogrid raw material, the model geogrid raw material is geosynthetic polymer powder or microparticles, and mainly comprises Polyethylene (PE), Polyester (PET), Polyamide (PER), polypropylene (PP), polyvinyl chloride (PVC), Chlorinated Polyethylene (CPE), polystyrene (EPS) and the like;

the spray head 12 is used for spraying the geogrid raw material provided by the geogrid raw material supply assembly;

the printing platform 2 is used for receiving geogrid raw materials sprayed by the spray head 12 to form a model geogrid 13;

the spray head moving assembly is used for driving the spray head 12 to move in the X-axis direction and the Z-axis direction under the control of the computer system 15;

the printing platform moving component is used for driving the printing platform 2 to move in the Y-axis direction under the control of the computer system 15;

and the computer system 15 is used for designing a three-dimensional model of the model geogrid in advance, and controlling the spray head moving assembly and the spray head moving assembly to adjust the relative height and position of the spray head 12 and the printing platform 2 according to the three-dimensional model.

Geogrid raw materials supply subassembly, including stock chest 3, conveying pipeline 4, slurry pump 11, stock chest 3 is fixed in 1 rear of printer frame, and the upper portion opening of stock chest 3, sealed all around, the bottom can be sealed and also can be opened for hold model geogrid raw materials. The outlet of the stock chest 3 is connected with a slurry pump 11 through a material conveying pipe 4, the slurry pump 11 is provided with a heating device, a spray head 12 is connected below the slurry pump, and the heating device is used for outputting the heated geogrid raw material.

The spray head moving assembly comprises an X-axis motor 5, an X-axis slide rail 10, a Z-axis motor 9 and a Z-axis slide rail 6, wherein the upper end and the lower end of each Z-axis slide rail 6 are respectively fixed on the printer frame 1, the two ends of each X-axis slide rail 10 are fixed on a Z-axis moving part of each Z-axis slide rail 6, the Z-axis motor 9 drives the Z-axis moving part to move up and down along the Z-axis slide rail 6, and the X-axis slide rail 10 moves along with the up-and-down movement of the Z-axis moving part on the Z-axis slide rail 6;

the printing platform moving assembly comprises a Y-axis motor 7 and a Y-axis sliding rail 8, the Y-axis sliding rail 8 is fixed at the lower part of the printer frame 1, the printing platform 2 is fixed on a support of the Y-axis sliding rail 8, the Y-axis motor 7 drives the support to move back and forth along the Y-axis sliding rail 8, and then the printing platform 2 is driven to move back and forth along the Y-axis sliding rail 8.

The slurry pump 11 and the spray head 12 are fixed on the X-axis slide rail 10, can be controlled by the X-axis motor 5 to move left and right along the X-axis slide rail 10, and move up and down along with the control of the Z-axis motor 9, and the printing platform 2 is controlled by the printing platform moving assembly to move back and forth along the Y axis so as to realize a 3D printing effect.

The heating devices in the X-axis motor 5, the Y-axis motor 7, the Z-axis motor 9, the slurry pump 11 and the slurry pump 11 are all connected with a computer system 15.

In this embodiment, the X-axis slide rail 6, the Y-axis slide rail 8 and the Z-axis slide rail 10 are made of steel or aluminum alloy, and have a length of 0.3-1.5 m and a diameter of 3-5 mm.

The embodiment of the invention also provides a method for preparing the fiber grating model geogrid based on 3D printing, which adopts the device for printing construction, and the method comprises the following steps:

(1) designing a three-dimensional model (shape, size and the like) of the geogrid model and a laying mode in a soil body by using three-dimensional drawing software installed in a computer system 15; the three-dimensional drawing software comprises 3Dmax, AutoCAD, UG, ProE or Solidworks and the like; the shape of the model geogrid can be the style shown in figures 3-5, and can also be various polygons, and the length of the geogrid can be designed to be 100-1000 mm;

(2) loading a geogrid raw material into a material storage tank 3 in a geogrid raw material supply assembly, opening a material conveying pump 11, conveying the geogrid raw material to a spray head 12 through a material conveying pipe 4, adjusting the discharging speed of the material storage tank to be 360-720 r/min, opening a heating device in the material conveying pump 11 of the geogrid raw material supply assembly, and adjusting the melting temperature of the raw material to be 220-480 ℃; the raw material of the geogrid is one or a mixture of Polyethylene (PE), Polyester (PET), Polyamide (PER), polypropylene (PP), polyvinyl chloride (PVC), Chlorinated Polyethylene (CPE) and polystyrene (EPS); the covering soil of the model grating can be broken stone, sand, clay and other materials, and the grading is good or bad;

(3) according to a preset three-dimensional model of the model geogrid in the computer system 15, controlling the spray head moving assembly and the spray head moving assembly to adjust the relative height and position of the spray head 12 and the printing platform 2, adjusting the position of the spray head 12 to a position (0.05 m in the embodiment) 0.01-0.2 m higher than the printing platform 2, adjusting the speed to a required speed through a valve, and starting to print the model geogrid by the model geogrid printing equipment;

(4) embedding a grid: in the process of printing the model geogrid, the geogrid is printed in an upper layer and a lower layer, the lower layer of the model geogrid is printed, a groove with the diameter of 0.5-5 mm is reserved during printing, an optical fiber grating sensor 14 (the diameter is 0.5-5 mm) is implanted into the reserved groove when the temperature of the lower layer of the model geogrid is reduced to 40-80 ℃, after embedding is completed, the upper layer of the model geogrid is printed, after printing is completed, an overlying pressure with the pressure of 2-35 kpa is applied to the encapsulated model geogrid, the model geogrid is fully bonded with the optical fiber grating sensor 14, and the internal embedding process of the optical fiber grating is completed;

(5) and (3) model test: after the model geogrid is printed, the model geogrid is embedded in soil or a gravel layer, the model geogrid is horizontally laid up and down according to a certain distance, the fiber grating sensor 14 is connected to the fiber grating acquisition system 17 (shown in figure 2), relevant model tests are carried out, the internal force and the strain of the model geogrid under the action of external load are monitored, and the external load comprises concentrated load, surface load, centrifugal force, earthquake action and the like.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.