Manufacturing method of concrete-filled steel tube member with defects based on 3D printing and magnetic hot melting technology
The defect information of steel pipe concrete components is obtained through ultrasonic array non-destructive testing and three-dimensional reverse reconstruction technology, and the defects and cracks are manufactured in combination with 3D printing and magnetothermal melting technology, which solves the problem of difficulty in accurately simulating the defects and cracks of old and old steel pipe concrete components in the prior art, and achieves a more reliable evaluation of its mechanical properties.
Patent Information
- Application Number
- CN202510285331.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-11
- Publication Date
- 2025-04-29
AI Technical Summary
The prior art is difficult to accurately judge and simulate defects and cracks in old and old steel pipe concrete components, resulting in the inability to fully reflect their true mechanical properties.
Ultrasonic array non-destructive detection technology is used to obtain defect information, generate digital models through three-dimensional reverse reconstruction technology, and combine 3D printing and magnetothermal melting technology to manufacture steel pipe concrete components with defects and cracks.
The precise simulation of defects and cracks in steel pipe concrete components is achieved, providing a more reliable test basis, and can fully reflect the mechanical properties of the steel pipe concrete structure in actual service.
Smart Images
Figure CN119897945A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a manufacturing method of a defective steel tube concrete component based on 3D printing and magnetic hot melting technology, and belongs to the technical field of additive manufacturing. Background Art
[0002] Steel tube concrete structures have the advantages of light weight, high bearing capacity and good ductility. They have been widely used in the field of civil engineering and have become key load-bearing components in large-span bridges, wind power foundations, transmission towers and high-rise building structures.
[0003] During the preparation, construction and service of steel tube concrete components, various types of void defects will inevitably occur, hindering the effective transfer of stress at the steel-concrete interface. Void defects refer to the cavities or gaps inside the concrete structure. This defect is usually caused by problems during the pouring, maintenance or use of concrete. For example, during construction, due to the inability to vibrate the pumped concrete, segregation and pores will occur at the steel-concrete interface, forming interfacial spot voids; during the construction of steel tube concrete arch bridges, the concrete flows at the horizontal part of the arch, which is prone to crown voids; due to the limitations of concrete preparation technology, components built in the early years that did not use self-compacting micro-expansive concrete have been in service for a long time, and cracks are everywhere in the concrete, which are seriously developed, especially old and old large-diameter steel tube concrete components. Moreover, during the long-term service process, the above defects and cracks continue to develop and deteriorate, seriously reducing the bearing capacity, stiffness and ductility of the structure, increasing the risk of damage to the structure under dynamic loads, corrosion, high temperature and other conditions, and ultimately forming the determining factors for controlling the comfort and safety of the steel tube concrete structure system.
[0004] In the existing technology, in 2023, Qin Chengjin of Guangxi University published a master's thesis: Research on non-destructive detection of void defects at the interface of steel-concrete composite structures, using synthetic aperture focusing imaging technology (SAFT) and piezoelectric ceramic testing technology to perform non-destructive, quantitative and intuitive detection of void defects at the interface of steel-concrete composite structures (steel tube concrete structures and steel-concrete composite panels). Piezoelectric ceramic testing technology can roughly determine the length of the void defect, and SAFT can identify the thickness of the defect. Therefore, it is recommended that the two be combined for steel tube concrete to obtain the comprehensive characteristics of the void defect. At present, there are few studies on steel tube concrete with void defects and cracks. The test components used are also intact components made in the laboratory or components that briefly simulate some defects by setting partitions, filling foam and other measures. The test results cannot fully and carefully reflect the true performance of steel tube concrete structures currently in service.
[0005] How to quantitatively determine the location, range, and distribution of defects and cracks in components, invert and construct steel tube concrete components with the same defects and crack parameters as real components, and conduct bearing performance tests is an important condition for evaluating the service bearing performance of existing old and outdated steel-concrete composite structures. The traditional practice is to drill and coring existing steel tube concrete components in service to test their structural performance, but this practice will cause certain damage to the existing structure, and in order not to further reduce the performance of the service structure, only small-sized local sampling can be performed. Therefore, the test results cannot fully reflect the entire component or structure. Summary of the invention
[0006] The present invention provides a method for manufacturing defective steel tube concrete components based on 3D printing and magnetic hot melting technology, the purpose of which is to restore the internal hollowing defects and cracks of steel tube concrete components in actual service, and to produce components close to those in actual engineering. By conducting experimental research under different loading conditions, the real performance of steel tube concrete structures currently in service is fully and meticulously reflected.
[0007] This method uses ultrasonic array nondestructive testing technology to detect defects and crack distribution of old and old steel tube concrete in actual projects, and realizes quantitative visualization of detection data through three-dimensional reverse reconstruction technology, obtains the physical and geometric characteristics of various void defects and types, scales, and distribution of cracks inside concrete, and uses magnetic hot melt adhesive to restore the above defects and cracks. 3D printing technology is used to print magnetic hot melt adhesive and concrete respectively, and corresponding scaled or prototype steel tube concrete test components are made, and component tests are carried out under corresponding load conditions, which is convenient for studying the mechanical properties of steel tube concrete structures with defects and cracks and guiding the evaluation of the service bearing performance of existing structures.
[0008] To achieve the above object, the present invention provides a method for manufacturing defective concrete-filled steel tube components based on 3D printing and magnetic hot melting technology, which specifically includes:
[0009] Step 1, extracting information on void defects and cracks of concrete-filled steel tube components during service life and generating images;
[0010] Step 2, converting the image into a three-dimensional digital model using three-dimensional inverse reconstruction technology;
[0011] Step 3, using 3D printing technology, using magnetic hot melt adhesive material to print out a solid main skeleton consistent with the shape of the crack and a hollow secondary body consistent with the shape of the hollow defect in the three-dimensional digital model;
[0012] Step 4, according to the distribution positions of cracks and void defects in the three-dimensional digital model, the solid main skeleton and the hollow auxiliary body are fixed at corresponding positions inside the steel pipe;
[0013] Step 5, using 3D printing technology to fill concrete into the gaps between the steel pipe, the solid main frame and the hollow auxiliary body;
[0014] Step 6: When the 3D printed concrete reaches a strength that is converted according to a similarity ratio with the concrete strength in the existing components, an alternating magnetic field is applied to the outer periphery of the steel tube to melt the solid main skeleton and the hollow secondary body, thereby obtaining a steel tube concrete component with void defects and cracks.
[0015] Furthermore, the method of extracting information on void defects and cracks of steel tube concrete components during their service life and generating images specifically comprises using an ultrasonic detector to perform ultrasonic nondestructive testing on steel tube concrete components in actual engineering structures, determining the wave velocity variation law of the most seriously defective area in the steel tube concrete components, and calibrating relevant information on the existence location and development degree of various defects in the steel tube concrete components under nondestructive conditions.
[0016] Furthermore, the ultrasonic detector utilizes ultrasonic array nondestructive testing technology to excite and receive stress wave pulses through a 4×12 dry-point transducer array and a control unit to collect data; the ultrasonic detector forms a 2D image of the interior of a concrete component with defects and cracks based on the collected data.
[0017] Furthermore, the 2D image data is converted into a 3D image model after being processed by 3D visualization software; using three-dimensional reverse reconstruction technology, the 3D ultrasonic image is converted into a digital model that can restore various defects in actual components and spatial distribution characteristics such as internal cracks in concrete.
[0018] Furthermore, noise reduction and binarization processing are required before converting the 2D image into a 3D image.
[0019] Furthermore, the hollow auxiliary body is bonded to the solid main frame or the inner wall of the steel pipe, and the solid main frame is fixed in the steel pipe by a positioning component.
[0020] Furthermore, the positioning assembly includes a bracket, a buckle base, a limit slider and an iron wire for binding the solid main frame. The limit slider is installed on the buckle base and can slide along the buckle base under the action of force. The bracket is provided with a threading hole. The bracket and the buckle base are radially spaced along the inner wall of the steel pipe. The iron wire is fixed on the limit slider after passing through the threading hole.
[0021] Furthermore, the buckle base includes a bottom plate and a top plate, the top plate is located on the bottom plate and is vertically arranged with the bottom plate, a plurality of grooves are provided in the middle of the top plate, and the limiting slider is provided with protrusions that are snap-fitted with the grooves.
[0022] The present invention discloses a method for manufacturing steel tube concrete components with defects and cracks based on 3D printing and magnetic hot melt technology. The beneficial effect is that compared with the prior art, it can more accurately obtain steel tube concrete components with defects and cracks close to those in actual engineering, providing a more reliable test basis for studying the real mechanical properties of steel tube concrete structures in actual service. Specifically, the present invention accurately obtains defect information through ultrasonic non-destructive testing to ensure the accuracy of the simulated 3D digital model; uses the precise molding of 3D printing technology and the characteristics of magnetic hot melt adhesive to restore the shape and position of defects and cracks to achieve real simulation, so that the physical parameters of the printed steel tube concrete components are closer to the real components. Under the action of the alternating magnetic field, the magnetic hot melt adhesive melts to obtain steel tube concrete components with hollow defects and cracks, providing a more reliable test basis for studying the mechanical properties of steel tube concrete structures in actual service, thereby achieving the effect of accurate simulation. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.
[0024] Figure 1 This is a schematic diagram of a two-dimensional image scanned by an ultrasound array in Example 1 of the present invention;
[0025] Figure 2 This is a schematic diagram of a three-dimensional image in Example 1 of the present invention;
[0026] Figure 3 A schematic diagram of a three-dimensional digital model generated by the three-dimensional reverse reconstruction technology in Example 1 of the present invention;
[0027] Figure 4 for Figure 3 Schematic diagram of the partial section;
[0028] Figure 5 This is a schematic diagram of a card holder in Example 1 of the present invention;
[0029] Figure 6 This is a schematic diagram of a buckle base in Example 1 of the present invention;
[0030] Figure 7 This is a schematic diagram of a limit slider in Embodiment 1 of the present invention;
[0031] Figure 8 This is a schematic diagram of the positioning assembly in Example 1 of the present invention being fixed in a steel pipe.
[0032] As shown in the figure: 1. Card holder; 2. Threading hole; 3. Bottom plate; 4. Top plate; 5. Groove; 6. Limit slider; 7. Bump; 8. Iron wire. DETAILED DESCRIPTION
[0033] In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0034] In order to further understand the content of the invention, this technical solution is further described below in conjunction with specific implementation methods.
[0035] Example 1: Figures 1 to 8 As shown, this embodiment provides a manufacturing method for steel tube concrete components with defects and cracks based on 3D printing and magnetic hot melting technology, which specifically includes: step 1, extracting the information of the hollow defects and cracks of the steel tube concrete components during the service life and generating an image; this embodiment uses an ultrasonic detector to perform ultrasonic non-destructive testing on the steel tube concrete components in the actual engineering structure, determine the wave velocity change law of the most and most serious defective areas in the steel tube concrete components, and calibrate the location of various defects in the steel tube concrete components under non-destructive conditions. The relevant key information of the development degree such as size, shape, depth, etc. The ultrasonic detector uses ultrasonic array non-destructive testing technology to excite and receive stress wave pulses through a 4×12 dry point transducer array and a control unit to collect data; the signal processing software of the ultrasonic detector forms a 2D image of the interior of the concrete component based on the collected data. For large-sized steel tube concrete components, due to the large number of internal defects and cracks, it is necessary to detect and image them section by section.
[0036] Step 2, use 3D reverse reconstruction technology to convert the image into a 3D digital model; specifically, the 2D image data is processed and "stitched" by 3D visualization software and converted into a 3D image model, such as using mimics software to convert the 2D image data collected by the ultrasonic detector into a 3D image model in STL format. Noise reduction and binarization processing are required before converting the 2D image into a 3D image. Using 3D reverse reconstruction technology, with the help of mimics software, the 3D ultrasonic image is converted into a 3D digital model that can restore the various defects in the actual component and the spatial distribution characteristics of the internal cracks of the concrete.
[0037] Step 3, using 3D printing technology, use magnetic hot melt adhesive material to print out a solid main skeleton consistent with the crack shape and a hollow auxiliary body consistent with the hollow defect shape in the three-dimensional digital model; according to the test component made according to the actual steel tube concrete component prototype, the corresponding solid main skeleton and hollow auxiliary body can be printed section by section.
[0038] Step 4, according to the distribution positions of cracks and hollow defects in the three-dimensional digital model, fix the entity main frame and the hollow auxiliary body at the corresponding positions inside the steel pipe respectively; specifically, the hollow auxiliary body is bonded to the entity main frame or the inner wall of the steel pipe, and the entity main frame is fixed in the steel pipe through a positioning component. The positioning component includes a bracket 1, a buckle base, a limit slider 6 and an iron wire 8 for binding the entity main frame. The limit slider 6 is installed on the buckle base and can slide along the buckle base under the action of force. The bracket 1 is provided with a threading hole 2, and the threading hole 2 is elliptical. The bracket 1 and the buckle base are radially spaced along the inner wall of the steel pipe. The iron wire 8 is fixed on the limit slider 6 after passing through the threading hole 2.
[0039] The buckle base includes a bottom plate 3 and a top plate 4, the top plate 4 is located on the bottom plate 3 and is vertically arranged with the bottom plate 3, the middle part of the top plate 4 is provided with a plurality of grooves 5, and the limit slider 6 is provided with a protrusion 7 that is engaged with the grooves 5. After the iron wire 8 is passed through the threading holes 2 on each of the clips 1 at the same height position one by one, the two ends of the iron wire 8 are respectively bound to the two limit sliders 6. In the process of binding the main skeleton of the entity with the iron wire 8 inside the steel pipe, according to the size of the entity skeleton, by adjusting the position of the limit slider 6 on the buckle base, the diameter of the annular ring surrounded by the iron wire 8 is adjusted accordingly, so as to achieve the purpose of matching the size of the entity skeleton and conveniently fixing it. After the main skeleton of the entity is fixed inside the steel pipe, according to the actual distribution of each type of defect, thin wooden strips of different lengths, 502 glue and other auxiliary materials are used to fix the hollow sub-bodies representing different types of defects at the corresponding positions of the entity skeleton and the inner wall of the steel pipe.
[0040] Step 5: After all the solid main frames and hollow auxiliary bodies are fixed, use 3D printing technology to print concrete and fill the entire steel pipe.
[0041] Step 6, when the 3D printed concrete reaches a strength matching that of the concrete in the existing components, the concrete strength conversion similarity ratio is 1:1, and an alternating magnetic field is applied to the outer periphery of the steel tube. In this embodiment, the alternating magnetic field strength is in the range of 5-15 kA / m, the alternating heating current is in the range of 10-100 A, and the magnetic field frequency is in the range of 100-180 kHz. The solid skeleton and each hollow sub-body buried in the concrete are melted, and then real cracks and corresponding types of defects are formed inside the component, thereby obtaining a steel tube concrete component with void defects and cracks.
[0042] Embodiment 2: Different from Embodiment 1, the ultrasonic detector directly scans and collects 3D images, and the 3D image data collected by the ultrasonic detector is converted into a 3D image model in STL format using mimics software. In addition, the test components are scaled according to the actual steel tube concrete components. The concrete strength conversion similarity ratio between the 3D printed concrete and the concrete in the existing components in the scaled test is 1:n, where the value of n is determined according to the scale ratio, and the corresponding solid main skeleton and hollow secondary body are printed section by section.
[0043] The present invention collects relevant data of actual steel tube concrete components by means of an ultrasonic detector under non-destructive conditions, and prints out a 3D solid model using 3D printing technology. In the process, a magnetic hot melt adhesive with magnetic hot melt properties is selected to print and restore a solid main skeleton that can simulate hollow sub-bodies of various types of hollow defects and various cracks. According to the 3D digital model information, the solid main skeleton and the hollow sub-bodies are fixed inside the steel tube to simulate the distribution of actual defects and cracks; under the action of an alternating magnetic field, the solid main skeleton and each hollow sub-body buried inside the concrete are melted, and then real cracks and corresponding types of defects are formed inside the component, and finally a steel tube concrete component with hollow defects and cracks is obtained. Under the premise of avoiding damage to existing steel tube concrete structural components, the present invention can more realistically simulate the hollow defects and cracks existing in steel tube concrete structures in actual engineering, facilitate the study of the mechanical properties of steel tube concrete structures in service, and guide the evaluation of the service bearing performance of existing structures.
[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for manufacturing defective steel tube concrete components based on 3D printing and magnetic hot melting technology, characterized in that: Specifically include: Step 1, extracting information on void defects and cracks of concrete-filled steel tube components during service life and generating images; Step 2, converting the image into a three-dimensional digital model using three-dimensional inverse reconstruction technology; Step 3, using 3D printing technology, using magnetic hot melt adhesive material to print out a solid main skeleton consistent with the shape of the crack and a hollow secondary body consistent with the shape of the hollow defect in the three-dimensional digital model; Step 4, according to the distribution positions of cracks and void defects in the three-dimensional digital model, the solid main skeleton and the hollow auxiliary body are fixed at corresponding positions inside the steel pipe; Step 5, using 3D printing technology to fill concrete into the gaps between the steel pipe, the solid main frame and the hollow auxiliary body; Step 6, when the concrete reaches a strength that is converted according to a similarity ratio with the strength of concrete in existing components, an alternating magnetic field is applied to the outer periphery of the steel tube to melt the solid main skeleton and the hollow secondary body, thereby obtaining a steel tube concrete component with void defects and cracks.
2. The method for manufacturing defective steel tube concrete components based on 3D printing and magnetic hot melting technology according to claim 1 is characterized in that: The information of void defects and cracks of steel tube concrete components during service life is extracted and images are generated. Specifically, an ultrasonic detector is used to perform ultrasonic non-destructive testing on steel tube concrete components in actual engineering structures, the wave velocity variation law of the most seriously defective area in the steel tube concrete components is determined, and the relevant information of the existence location and development degree of various defects in the steel tube concrete components is calibrated under non-destructive conditions.
3. The method for manufacturing defective concrete-filled steel tube components based on 3D printing and magnetic hot melting technology according to claim 2 is characterized in that: The ultrasonic detector uses ultrasonic array nondestructive testing technology to excite and receive stress wave pulses through a 4×12 dry-point transducer array and a control unit to collect data; the ultrasonic detector forms a 2D image of the interior of concrete components with defects and cracks based on the collected data.
4. The method for manufacturing defective steel tube concrete components based on 3D printing and magnetic hot melting technology according to claim 3 is characterized in that: The 2D image data is converted into a 3D image model after being processed by 3D visualization software; using 3D reverse reconstruction technology, the 3D ultrasonic image is converted into a 3D digital model that can restore various defects in the actual components and cracks inside the concrete.
5. The method for manufacturing defective steel tube concrete components based on 3D printing and magnetic hot melting technology according to claim 4 is characterized in that: Before converting 2D images into 3D images, noise reduction and binarization processing are required.
6. The method for manufacturing defective steel tube concrete components based on 3D printing and magnetic hot melting technology according to claim 1 is characterized in that: The hollow auxiliary body is bonded to the solid main frame or the inner wall of the steel pipe, and the solid main frame is fixed in the steel pipe through a positioning component.
7. The method for manufacturing defective concrete-filled steel tube components based on 3D printing and magnetic hot melting technology according to claim 6 is characterized in that: The positioning assembly comprises a card holder (1), a buckle base, a limit slider (6) and an iron wire (8) for binding a solid main frame. The limit slider (6) is installed on the buckle base and can slide along the buckle base under the action of force. The card holder (1) is provided with a threading hole (2). The card holder (1) and the buckle base are radially spaced along the inner wall of the steel pipe. The iron wire (8) is fixed on the limit slider (6) after passing through the threading hole (2).
8. The method for manufacturing defective concrete-filled steel tube components based on 3D printing and magnetic hot melting technology according to claim 1, characterized in that: The buckle base comprises a bottom plate (3) and a top plate (4), wherein the top plate (4) is located on the bottom plate (3) and is vertically arranged with the bottom plate (3), a plurality of grooves (5) are provided in the middle of the top plate (4), and a protrusion (7) which is snap-fitted with the grooves (5) is provided on the limit slider (6).