CN-122014010-A - Reinforced structure of open section steel wound by optimized structure filling blocks and FRP fibers based on additive manufacturing, construction method and application

CN122014010ACN 122014010 ACN122014010 ACN 122014010ACN-122014010-A

Abstract

The invention relates to the technical field of steel structure reinforcement, in particular to an open section steel reinforcement structure based on additive manufacturing and winding of an optimized structure filling block and FRP fibers, and a construction method and application thereof, and aims to solve the problems of poor FRP laminating performance and low reinforcement efficiency caused by geometric characteristic limitation of the open section steel. The reinforcing structure comprises an optimized structure filling block which is manufactured by additive manufacturing and is fixed at a concave surface of the section steel, wherein the optimized structure filling block has a geometric form optimized based on a preset performance target, such as an optimized internal section (such as a honeycomb or lattice structure) and/or an optimized longitudinal layout (such as a functional gradient or topological optimization), and FRP fiber winding layers which are continuously wound on the outer surfaces of the optimized structure filling block and the section steel. The optimized structure filling block converts the opening section into a closed section favorable for winding, and forms a cooperative stress system with the FRP fiber winding layer. The FRP fiber winding layer provides circumferential restraint to inhibit local buckling, and the FRP fiber winding layer jointly strengthen the mechanical property of the section. The method is particularly suitable for repairing and reinforcing the open section steel members bearing complex loads, such as power transmission towers, bridge supports and the like.

Inventors

YU TAO
XIA ZHIYU
XIANG YU
DENG JIE

Assignees

港理大（温州）技术创新研究院有限公司
香港理工大学

Dates

Publication Date: 20260512
Application Date: 20260115

Claims (10)

1. The open section steel reinforced structure based on the additive manufacturing and wound by the FRP fiber is characterized by comprising open section steel, the additive manufacturing optimized structure filling block and an FRP fiber wound layer; wherein the cross section form of the optimized structure filling block for additive manufacturing is a closed cross section; The optimized structure filling block manufactured by the additive is attached to the concave surface of the section steel with the opening, and the FRP fiber winding layer is continuously wound on the outer surfaces of the optimized structure filling block manufactured by the additive and the section steel with the opening.
2. The reinforced structure of the open section steel based on the additive manufacturing optimization structure filling block and the FRP fiber winding, as set forth in claim 1, wherein the section of the open section steel after the additive manufacturing optimization structure filling block is attached to the concave surface of the open section steel has a smooth outer contour.
3. The open section steel reinforced structure based on additive manufacturing optimized structure filling blocks and FRP fiber winding of claim 1, wherein the internal section shape of the optimized structure filling blocks manufactured by additive is honeycomb structure or lattice structure; the longitudinal layout of the optimized structure filling block for additive manufacturing is of a variable density structure, and the material distribution is matched with a stress field under a preset load working condition and is determined through functional gradient or topological optimization.
4. The open section steel reinforcing structure based on additive manufacturing optimization structure filling blocks and FRP fiber winding as claimed in claim 1, wherein the additive manufacturing optimization structure filling blocks are attached to the concave surfaces of the open section steel through cementing and/or mechanical connection; The FRP fiber winding layer is made of any one or combination of (1) wet winding fiber bundles, namely dry fiber bundles which are in-line impregnated by a resin groove in the winding process, and (2) thermoplastic prepreg tape, namely fiber tape which is impregnated by a thermoplastic resin matrix, and is in-situ heated, melted and solidified in the winding process.
5. The open section steel reinforcement structure based on optimized structural filler blocks for additive manufacturing and FRP fiber winding of claim 1, wherein the FRP fiber winding layer adopts a layered multi-angle configuration system, a near-circumferential winding layer is configured in a section needing to mainly inhibit local buckling or prevent circumferential cracking, the fiber winding angle is 75-90 degrees relative to the longitudinal axis of a component, an oblique cross winding layer is configured in a section needing to enhance bending-torsion coupling rigidity or shearing capacity, the fiber winding angle is +/-30- +/-60 degrees, and an inner layer is configured as a small-angle spiral layer in a section needing to cooperatively improve longitudinal bearing capacity, the winding angle is +/-10- +/-30 degrees, and an outer layer covers the near-circumferential winding layer to form closed constraint.
6. A method of constructing an open section steel reinforced structure wound with FRP fibers and optimized structure-filling blocks based on additive manufacturing as claimed in any one of claims 1 to 5, comprising: step one, preprocessing the section steel with the open section; step two, manufacturing an optimized structure filling block by additive; step three, attaching the optimized structure filling block manufactured by the additive to the concave surface of the pretreated open section profile steel through cementing and/or mechanical connection; Step four, finishing winding of the FRP fiber winding layer on the outer surface of the optimized structural filling block manufactured by the additive and the open section profile steel by adopting an automatic continuous fiber winding technology; and fifthly, curing and post-treating the FRP fiber winding layer to obtain the open section steel reinforced structure.
7. The construction method of the reinforced structure of the open section steel based on the additive manufacturing optimization structure filling blocks and the FRP fiber winding is characterized in that the first step specifically comprises the steps of firstly carrying out geometric correction on the open section steel and then carrying out surface decontamination and rust removal treatment on the open section steel.
8. The construction method of the open section steel reinforced structure based on additive manufacturing and wound by FRP fiber is characterized in that the second step specifically comprises the following steps: Acquiring surface three-dimensional point cloud data of the section to be reinforced of the open section steel by using non-contact three-dimensional scanning equipment; reconstructing a digital model reflecting the real geometric characteristics and deformation states of the open section profile steel based on the three-dimensional point cloud data; Constructing a virtual envelope body with a preset closed outline, and subtracting the digital model from the virtual envelope body through Boolean subtraction operation; Based on the preset thickness of the adhesive layer, carrying out normal bias compensation on the contact surface after Boolean operation to generate the outer contour of the manufacturing model of the optimized structure filling block; adopting finite element analysis, topology optimization or bionic design to generate a three-dimensional numerical model of the optimized structure filling block for additive manufacturing; inputting the three-dimensional numerical model into additive manufacturing equipment, and manufacturing the optimized structural filling block by additive.
9. The construction method of the reinforced structure of the open section steel wrapped by FRP fiber based on the optimized structure filling block manufactured by additive materials according to claim 6, wherein the fifth step comprises the steps of sealing the edges, joints and ends of the FRP fiber wrapped layer by epoxy resin paste after the FRP fiber wrapped layer is completely cured, and coating durable protective finishing paint on the exposed surface after curing.
10. Use of the optimized structure filling block based on additive manufacturing and the FRP fiber wound open section steel reinforced structure according to any one of claims 1 to 5 in power transmission towers, bridge supports, industrial factory building crane beams, ocean platform support members.

Description

Reinforced structure of open section steel wound by optimized structure filling blocks and FRP fibers based on additive manufacturing, construction method and application Technical Field The invention belongs to the technical field of steel structure reinforcement, and particularly relates to an open section steel reinforcement structure based on continuous winding of an optimized structure filling block and a fiber reinforced polymer (Fiber Reinforced Polymer, FRP) in additive manufacturing (Additive Manufacturing, 3D printing for short), and a construction method and application thereof. Background The open section steel (such as angle steel, channel steel, I-steel and the like) is widely applied to engineering structures such as power transmission towers, bridge supports and the like due to the advantages of simple manufacturing process, high stress efficiency and the like. However, the inherent open cross section and asymmetric geometry thereof result in greater reinforcement difficulty and difficulty in securing reinforcement reliability, thereby affecting structural safety. Although the traditional welding steel plate reinforcing method can improve the structural strength, the construction is complex, the additional self weight is great, and the welding residual stress can bring hidden danger, thereby being unfavorable for the light weight and the durability requirement. In recent years, fiber Reinforced Polymer (FRP) has become an important research direction in the field of steel structure reinforcement due to the remarkable advantages of high strength, light weight, corrosion resistance, flexible construction and the like. In the prior art, the typical practice of FRP reinforcing open section steel is to paste FRP cloth or FRP sheet material directly along the outer surface of the member. For example, a plurality of layers of unidirectional FRP cloth are generally used for wrapping the outer surface of the angle steel so as to improve the bending bearing capacity, but the geometrical characteristics of the concave surface of the section steel are not fully considered in the method, so that the FRP is not tightly attached to the concave surface, and the phenomena of stress concentration and interfacial peeling are easily caused. In addition, the reinforcing mode generally depends on manual pasting construction, is difficult to form a standardized and automatic process, and is low in efficiency and high in labor cost. Whereas FRP materials have anisotropy, most FRP cloths and plates are unidirectional fiber products, and when buckling occurs in a reinforced steel member, the adhesive layer is liable to interfacial peeling. It has been shown that although the flexural resistance of the component can be improved by increasing the number of longitudinal FRP layers, local buckling of the fibrous layers is easily induced in the absence of lateral restraint, while the improvement in torsional stiffness is limited. In addition, the unidirectional fiber reinforcement fails to fundamentally solve the problem of low torsional rigidity of the open section steel, so that the reinforced structure is still easy to laterally unstably under the action of large lateral load or dynamic wind load. The limitation of the technology is mainly characterized in that firstly, the FRP is difficult to uniformly attach on the concave surface due to the concave geometric characteristic of the section steel with the opening section, and a weak area of an interface is easily formed by stress concentration, and secondly, the performance improvement of the section steel with the opening section is mainly dependent on the wrapping of the FRP in a single direction, and buckling and torsion are difficult to inhibit. Therefore, development of an efficient reinforcing method for geometric characteristics of the open section steel is needed to improve the adhesion strength and the construction efficiency of the FRP on the concave surface of the open section and improve the comprehensive mechanical properties of the reinforcing structure. Disclosure of Invention Aiming at the problems of poor concave surface laminating property and low construction efficiency when FRP reinforcement is adopted in the open section profile steel in the prior art, the invention provides a reinforcing structure based on additive manufacturing and formed by winding optimized structure filling blocks and FRP fibers, and a construction method and application thereof. The technical scheme of the invention is as follows: the invention provides an open section steel reinforced structure based on additive manufacturing and wound by optimized structure filling blocks and FRP fibers, which comprises open section steel, the optimized structure filling blocks and an FRP fiber wound layer; wherein the cross section form of the optimized structure filling block for additive manufacturing is a closed cross section; The optimized structure filling block manufactured by the ad