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CN-121972761-A - Sequential collaborative manufacturing method for reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing

CN121972761ACN 121972761 ACN121972761 ACN 121972761ACN-121972761-A

Abstract

The invention discloses a sequential collaborative forming process method of a reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing, and belongs to the technical field of additive manufacturing. The method comprises the steps of carrying out space structure design and multi-head path planning of the steel bars according to bearing requirements, selecting a single-wire arc or double-heat source deposition mode according to the diameters of the steel bars, adaptively adjusting technological parameters according to space forming angles to achieve 0-90-degree full-angle unsupported forming, implementing thermal field coupling control and safe distance avoidance strategies during multi-arc parallel manufacturing, determining concrete manufacturing time sequence windows (80-200 ℃) after the steel bars are cooled based on a transient temperature field evolution model, achieving layer-by-layer alternate forming of the steel bars and the concrete through the zonal time sequence strategies, and implementing quality monitoring and closed-loop control in the whole process.

Inventors

  • Chen Binling
  • Shi Kaifan
  • JING CHENCHEN

Assignees

  • 北京理工大学

Dates

Publication Date
20260505
Application Date
20260320

Claims (10)

  1. 1. The sequential collaborative forming process method of the reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing is characterized by comprising the following steps of: Step S1, a three-dimensional model of a reinforced bar space layout is established according to the bearing requirement of a target reinforced concrete structure, the established three-dimensional model is subjected to path decomposition, the motion trail of each arc additive manufacturing head is generated, and the generated motion trail is distributed to N arc additive manufacturing heads according to the reinforced bar space layout; S2, determining arc additive manufacturing process parameters; s3, determining technological parameters by adopting the step S2 to perform multi-arc parallel reinforcement additive manufacturing; And S4, performing time sequence cooperative control on the reinforced concrete to finish a time sequence cooperative forming process of the reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing.
  2. 2. The sequential co-forming process method for the reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing of claim 1, wherein the sequential co-forming process method is characterized by comprising the following steps of: in the step S1, the three-dimensional model of the spatial layout of the reinforcement bar includes spatial coordinate information, diameter information and forming angle information of longitudinal bars, stirrups and nodes.
  3. 3. The sequential co-forming process method for the reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing of claim 1, wherein the sequential co-forming process method is characterized by comprising the following steps of: In the step S1, path decomposition follows the principle that a single steel bar is continuously formed along the axial direction of the single steel bar, a cross lap joint or surrounding cladding strategy is adopted at a node, and the forming time interval between adjacent steel bars is not smaller than a preset minimum cooling interval Tmin.
  4. 4. The sequential co-forming process method for the reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing of claim 1, wherein the sequential co-forming process method is characterized by comprising the following steps of: in step S1, the allocation principle is to minimize the spatial interference of each manufacturing head while balancing the workload of each manufacturing head.
  5. 5. The sequential co-forming process method for the reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing of claim 1, wherein the sequential co-forming process method is characterized by comprising the following steps of: in the step S2, the method for determining the arc additive manufacturing process parameters includes: S2.1, determining basic technological parameters of arc additive manufacturing according to a target steel bar diameter d, wherein the basic technological parameters comprise welding current I_w, wire feeding speed V_f, traveling speed V_t and pulse frequency f_p; s2.2, a dual heat source deposition mode of combining pulse arc with a hot wire power supply is adopted for manufacturing the steel bar, wherein the hot wire preheating temperature T_h is set to 300-500 ℃; S2.3, adaptively adjusting basic process parameters according to the space forming angle theta of the reinforcing steel bars: When θ=0 to 30 degrees, the welding current is reduced to 70 to 85 percent of I_w, the pulse frequency is increased to 120 to 150 percent of f_p, and the pulse peak time is shortened to 60 to 80 percent of the basic value; When θ=30 to 60 °, the welding current is adjusted to 85 to 95% of i_w, and the pulse frequency is adjusted to 105 to 120% of f_p; When θ=60° -90 °, the basic process parameters i_w and f_p are used.
  6. 6. The sequential co-forming process method for the reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing of claim 1, wherein the sequential co-forming process method is characterized by comprising the following steps of: in the step S3, the method for manufacturing the multi-arc parallel reinforcing steel bar additive comprises the following steps: s3.1, synchronously starting N arc additive manufacturing heads according to the distributed paths, wherein each manufacturing head independently operates respective technological parameters; s3.2, implementing a thermal field coupling control strategy in a multi-arc parallel process, wherein when the spatial distance between any two manufacturing heads is smaller than the safety distance D_s, the manufacturing heads started later pause or switch to an alternative path segment, and continue to execute the original path after the distance is restored to be larger than the safety distance D_s; S3.3, monitoring the shape of each arc molten pool in real time by adopting a CCD camera, and reducing the welding current by 5% -15% in real time until the shape of the molten pool is recovered to be normal when the width of the molten pool is monitored to be more than 130% of the diameter of a target reinforcing steel bar or the aspect ratio of the molten pool is monitored to be more than 2.5:1; S3.4, when the steel bar node is formed, adopting a surrounding coating deposition strategy, wherein the first manufacturing head pauses at the node position after finishing the main steel bar deposition, and the second manufacturing head performs 2-4 layers of coating deposition along the circumferential direction at the node to form a node reinforcing area, and the temperature between coating deposition layers is controlled to be 200-350 ℃.
  7. 7. The sequential co-forming process method for the reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing of claim 1, wherein the sequential co-forming process method is characterized by comprising the following steps of: In the step S4, the method for cooperatively controlling the time sequence of the reinforced concrete is as follows: S4.1, establishing a transient temperature field evolution model of reinforcement arc additive manufacturing, and calculating a cooling curve T_s (T) of each section of reinforcement after the deposition is completed, wherein T is the time after the deposition is completed; s4.2, determining a starting time sequence window of concrete additive manufacturing, namely after the steel bar section is deposited, starting the concrete additive manufacturing of the area when the temperature T_s of the steel bar surface is reduced to 80-200 ℃; s4.3, the concrete additive manufacturing adopts a lamination forming mode or a spray forming mode, wherein the single layer height of the lamination forming mode is 8-15 mm, the waiting time between layers is 30-120S, the spray distance of the spray forming mode is 200-400 mm, and the spray pressure is 0.3-0.8 MPa; S4.4, in the reinforced bar-concrete composite area, the concrete additive path is carried out around the reinforced bars, so that the concrete is ensured to completely wrap the reinforced bars, and the thickness of a reinforced bar protection layer is not less than 15mm; s4.5, implementing a partition time-sequence manufacturing strategy, namely dividing the reinforcing steel bar into a plurality of forming layers in the height direction, wherein the manufacturing process of each forming layer is that firstly, the arc additive manufacturing head finishes the forming of the reinforcing steel bar of the layer, and after cooling to a time sequence window, the concrete additive manufacturing head finishes the forming of the concrete of the layer, and the cycle is repeated until the integral forming is finished.
  8. 8. The sequential co-forming process method for the reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing of claim 5, wherein the sequential co-forming process method is characterized by comprising the following steps of: In the step S2.1, for the steel bars with the diameter of 8mm, basic technological parameter combinations are that welding current I_w=90A-130A, wire feeding speed V_f=3.0 m/min-5.5 m/min, running speed V_t=0.3 m/min-0.6 m/min, pulse frequency f_p=40 Hz-120 Hz, shielding gas is 95% Ar+5% CO2 mixed gas, and gas flow is 15L/min-25L/min; in the step S2.2, the power of a hot wire power supply in a double heat source deposition mode is 1.5 kW-3.0 kW, a hot wire mechanism is connected to a wire feeding nozzle, and preheating of welding wires is completed in the wire feeding process.
  9. 9. The sequential co-forming process method for the reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing of claim 6, wherein the sequential co-forming process method is characterized by comprising the following steps of: In the step S3.2, the safety distance D_s is dynamically adjusted according to the simultaneous working quantity of N arc manufacturing heads, wherein when the simultaneous working quantity of the manufacturing heads is less than or equal to 4, D_s=150 mm, when the simultaneous working quantity of the manufacturing heads is 5-8, D_s=200 mm, and when the simultaneous working quantity of the manufacturing heads is 9-16, D_s=300 mm; in the step S3.4, a variable pitch strategy is adopted for surrounding cladding deposition of the node reinforcing region, the spacing between cladding layers close to the center of the node is 1.5 mm-2.0 mm, and the spacing between cladding layers far from the center of the node is 2.5 mm-3.5 mm.
  10. 10. The sequential co-forming process of a reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing of claim 7, wherein the process comprises the following steps: In the step S4.2, the temperature range of the time sequence window is adjusted according to the concrete mixing proportion, wherein the time sequence window is 80-150 ℃ for ordinary silicate cement concrete, 80-120 ℃ for high-alumina cement concrete, and 80-200 ℃ for geopolymer-based concrete; In the step S4.5, the single-layer height H_layer of the partitioned time-ordered manufacturing strategy is determined according to the overall type, wherein H_layer=30 mm-60 mm for a column structure, H_layer=20 mm-40 mm for a beam structure, and H_layer=15 mm-30 mm for a plate structure.

Description

Sequential collaborative manufacturing method for reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing Technical Field The invention relates to the technical field of additive manufacturing, in particular to a sequential collaborative forming process method of a reinforced concrete composite structure based on multi-arc parallel arc additive manufacturing, which is suitable for integrated additive manufacturing of the reinforced concrete composite structure in road and bridge construction and infrastructure engineering. Background The reinforced concrete structure is the most widely used structural form in road and bridge construction and infrastructure engineering due to its excellent bearing performance. The traditional construction method needs to undergo a plurality of independent procedures such as reinforcement bar binding, template construction, concrete pouring, vibration maintenance and the like, has long construction period, high labor intensity and serious template material waste, and is difficult to realize efficient manufacturing of complex abnormal structures. In recent years, a concrete 3D printing technology (also called concrete additive manufacturing) is rapidly developed, template-free layer-by-layer stacking forming can be realized, and great potential is shown in the field of construction. However, current concrete additive manufacturing techniques face a core bottleneck, the reinforcement difficulty. The prior art mainly depends on the mode of presetting a traditional reinforcement cage or post-implantation reinforcement, and has the following problems that (1) the preset reinforcement cage needs manual binding, so that the preset reinforcement cage has the obvious defects of high labor intensity of workers, inconsistent manual binding quality and low efficiency, (2) the post-implantation reinforcement cannot realize reinforcement arrangement in any direction in space, the degree of freedom of structural design is limited, and (3) the interface bonding quality between the reinforcement and additive manufacturing concrete is difficult to ensure, so that the integral bearing performance of the structure is influenced. The arc additive Manufacturing (WAAM) technology uses an arc as a heat source, takes metal wires as raw materials, realizes near-net forming of metal components through layer-by-layer cladding, and has the advantages of high deposition efficiency, low equipment cost, capability of Manufacturing large-size components and the like. The arc additive manufacturing technology is applied to space arbitrary forming of the reinforced bar and is compounded with concrete additive manufacturing, so that full-automatic integrated forming of the reinforced concrete structure is hopeful to be realized. However, the composite process of steel bar electric arc additive manufacturing and concrete additive manufacturing faces a plurality of technical challenges, namely firstly, the problem of suspension forming stability of the steel bar manufactured by electric arc additive manufacturing, accurate control of thermodynamic behavior of a molten pool is needed to realize accurate forming of steel bars at any angle in space under an unsupported condition, secondly, the difference of thermal physical characteristics of two materials of the steel bar and the concrete is obvious, a huge temperature difference exists between high temperature (more than 1500 ℃ C.) of the steel bar for electric arc additive manufacturing and the hydration solidification process (normal temperature to about 80 ℃ C.) of the concrete, and how to realize effective time sequence coordination of the two is a core difficult problem, thirdly, in order to meet the requirements of engineering application on efficiency and cost, a multi-arc parallel efficient manufacturing strategy needs to be developed, and the problem of thermal field coupling and interference when multiple arcs work simultaneously is to be solved. In the prior art, chinese patent CN115198810A discloses a 3D printing method of a metal-concrete composite material, but the method only relates to simple compounding of a single arc head, and cannot realize multi-arc parallel high-efficiency manufacturing, and CN116833538A discloses a method for manufacturing reinforcing steel bars by arc additive, but does not relate to compounding manufacturing time sequence control of the reinforcing steel bars and concrete. At present, a reinforced bar-concrete composite additive manufacturing process method with multi-arc parallel high-efficiency manufacturing and space arbitrary forming and time sequence cooperative control is not available. Disclosure of Invention Aiming at the problems of low manufacturing efficiency, limited space forming capability, uncontrollable interface bonding quality and the like of the reinforced bar-concrete composite additive in the prior art, the invention provides a sequential collaborative forming pro