Multifunctional composite protective structure for polar equipment with low-temperature brittle fracture prevention

Abstract

The application provides a polar equipment with a multifunctional composite protection structure against low-temperature brittle fracture, which is a prefabricated modular plate component and is fixed on the outside of the base body of the polar equipment; the protection structure comprises an impact-resistant heating layer, a plurality of porous closed flow channels for circulating heating medium are formed in the impact-resistant heating layer, and a medium inlet and a medium outlet are arranged on the impact-resistant heating layer, so that a heat source pipeline can be connected to introduce the circulating heating medium; the circulating heating medium is high-temperature seawater waste heat source discharged by a ship generator set, waste heat can be recycled, the ship body parent material is in-situ heated through medium heat exchange to improve the service temperature, the temperature is actively controlled to avoid the low-temperature brittleness of the ship structure, and the impact energy is dissipated through the fluid damping effect when the porous closed flow channels are subjected to impact load. Through the synergistic effect of active heating and fluid damping, the application can eliminate the low-temperature brittleness inducement and effectively attenuate the impact load peak under the condition of not consuming additional energy from the service environment level; meanwhile, the prefabricated modular installation does not need to cut or weld the base body for modification, and can realize rapid installation and removal.

Description

Technical Field

[0001] This invention relates to the field of polar vessel protective structure technology, and more specifically, to a multifunctional composite protective structure for polar equipment that is designed to withstand low-temperature brittle fracture. Background Technology

[0002] With the in-depth development of polar scientific research, ocean shipping, and resource exploration industries, polar equipment such as icebreakers and polar transport ships are rapidly iterating towards larger size and higher performance. As the core structure directly facing the impact of floating ice and exposed to extreme marine environments in all weather conditions, the bow and waterline ice zone of polar vessels operate year-round under harsh conditions of low temperatures, dense floating ice, high salt spray, high humidity, and high dissolved oxygen. This unique environment has long presented three common technical challenges in this area: low-temperature brittle fracture, floating ice impact damage, and corrosion failure of the protective system, which seriously restrict the service safety and service life of polar equipment.

[0003] To address the aforementioned issues, existing technologies typically employ a piecemeal approach. For example, patent application number 202211565096.7 discloses an anti-icing system for the deck of polar vessels utilizing waste heat from chimneys. This system prevents deck icing by recovering waste heat from main engine exhaust. However, this system primarily addresses surface icing and does not address the low-temperature brittleness protection and ice impact resistance of the ship's structure itself. Another example is patent application number 200910073071.3, which discloses a combined marine impact-resistant structure. This structure uses a combination of semi-circular tube sandwich panels and trapezoidal longitudinal reinforcement, utilizing the plastic deformation of thin-walled components to absorb impact energy. While it possesses good impact resistance, it is a passive protection method and cannot address the fundamental problem of material performance degradation in low-temperature environments. It also lacks long-term corrosion protection and intelligent monitoring capabilities.

[0004] Therefore, there is an urgent need for a multifunctional composite protective structure that integrates active temperature control and embrittlement prevention, high-efficiency impact resistance, long-term corrosion protection, and intelligent sensing to comprehensively improve the protective effectiveness of critical areas of polar ships. Summary of the Invention

[0005] In view of this, the present invention aims to propose a multi-functional composite protective structure for polar equipment, which is a hanging type to prevent low-temperature brittle fracture, in order to solve three problems in the prior art: the inability to actively suppress low-temperature brittle fracture in the ice zone of polar ships, permanent structural deformation caused by ice floe impact, and easy peeling of anti-corrosion coatings that induce electrochemical corrosion of the base material; at the same time, it realizes in-situ self-monitoring of structural damage and resource utilization of ship waste heat.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0007] This invention provides a multi-functional composite protective structure for polar equipment, which is a prefabricated modular plate component that is attached and fixed to the outside of the polar equipment.

[0008] The protective structure includes an impact-resistant heating layer, which has a porous closed flow channel for circulating heating medium. The impact-resistant heating layer is provided with a medium inlet and a medium outlet that are connected to the porous closed flow channel for connecting an external heat source pipeline to introduce the circulating heating medium.

[0009] The circulating heating medium is used to conduct heat energy to the inner substrate to increase its service temperature; the circulating heating medium also dissipates impact energy through fluid damping effect when subjected to external impact loads in the porous closed flow channel.

[0010] In this invention, the substrate is the original main structure of polar equipment, specifically referring to the hull structure of polar equipment (such as icebreakers, polar transport ships, research stations, etc.).

[0011] It should be noted that the fluid damping effect refers to the fact that when an external impact load acts on the protective structure, the liquid medium in the porous closed flow channel cannot be discharged instantaneously due to inertia, forming a transient high-pressure zone inside the flow channel and generating viscous resistance, which converts the impact kinetic energy into internal energy and wall friction energy for dissipation, thereby inhibiting the transmission of the impact load to the substrate.

[0012] In this invention, the heating medium is high-temperature seawater discharged from the cooling system of the ship's generator set, which is introduced into the porous closed flow channel inside the impact-resistant heating layer through an external hose. When the high-temperature seawater circulates in the flow channel, it continuously exchanges heat with the inner substrate through the corrugated wall, and heats the hull material in situ by means of heat conduction, so that the service temperature of the steel rises above its ductile-brittle transition temperature, thereby actively eliminating the inducing conditions of low-temperature brittle fracture from the perspective of the service environment.

[0013] In this invention, the impact-resistant heating layer includes a corrugated metal plate with a continuous wave pattern. The crests and troughs of the corrugated plate are sealed by panels to form a horizontally extending, closed-loop flow channel within the impact-resistant heating layer. The impact-resistant heating layer is provided with a medium inlet and a medium outlet communicating with the porous, closed flow channel. The medium inlet and outlet are located on the sidewall or end of the impact-resistant heating layer and connected in series to the cooling seawater pipeline of the ship's generator set via an external flexible hose. The high-temperature seawater discharged after heat exchange by the generator set enters the corrugated cavity through the medium inlet, forming a closed loop.

[0014] On the one hand, the circulating high-temperature water continuously conducts heat to the inner substrate through the corrugated cavity, steadily increasing the service temperature of the substrate and eliminating the causes of low-temperature embrittlement of the steel from the perspective of the service environment. On the other hand, when the impact load of floating ice acts on the outside of the protective structure, the metal corrugated wall dissipates the impact energy through its own crushing deformation, while the circulating liquid inside the porous closed flow channel further dissipates the impact kinetic energy through the fluid damping effect, forming a dual impact-resistant energy absorption mechanism of structural plastic deformation + liquid viscosity energy dissipation. Compared with hollow corrugated plates and solid steel plates, the liquid-filled configuration of this invention can significantly reduce the plate surface indentation and structural buckling deformation caused by impact loads.

[0015] In this invention, the impact-resistant heating layer is processed into a continuous corrugated structure using a roll forming process, with a wall thickness of 2~3.5mm and a single corrugation height of 20~50mm.

[0016] Furthermore, the protective structure also includes a self-sensing functional layer disposed inside the impact-resistant heating layer;

[0017] The self-sensing functional layer includes a conductive network configured to change resistance with temperature, structural deformation, or damage, for in-situ monitoring of temperature, structural cracks, local stress, and deformation points.

[0018] It should be noted that the self-sensing functional layer is located on one side of the substrate that is in close contact with the polar equipment, serving as the innermost functional layer of the protective structure, so as to directly sense changes in the structural state of the substrate surface.

[0019] Furthermore, the conductive network includes two orthogonally stacked conductive films, which are arranged in the horizontal and vertical directions respectively and have independently led out coded wiring terminals to form a two-dimensional matrix sensing array.

[0020] The two conductive films are respectively connected to the signal acquisition module. The conductive network is used to sense the temperature distribution and structural state of the protective structure. When the temperature of the monitoring area changes, the resistance of the conductive network changes accordingly according to the thermal resistance effect to achieve temperature monitoring. When the structure is deformed or damaged, the conductive network at the corresponding position is stretched or broken, causing a sudden change in resistance. The deformation or damage coordinates are located by encoding changes.

[0021] In this invention, the self-sensing functional layer is a carbon nanotube composite conductive film. The film contains a uniformly dispersed three-dimensional porous carbon nanotube conductive network, giving the self-sensing functional layer both thermal and mechanical resistance effects: the resistance changes regularly with temperature variations, and changes abruptly with structural deformation or damage.

[0022] In this invention, the self-sensing functional layer is bonded to the impact-resistant heating layer with high-temperature resistant epoxy adhesive. This serves both as a sensing layer for in-situ monitoring and as a structural interface transition layer, preventing delamination and debonding between adjacent layers under extreme low temperatures and alternating load conditions. In this invention, the self-sensing functional layer is a carbon nanotube-modified epoxy resin-based conductive film with a thickness of 0.3~0.5 mm. The conductive network consists of two conductive substrate layers orthogonally stacked at 90° to form a two-dimensional matrix sensing array, with each line coding terminal extending from the edge of the film.

[0023] Furthermore, the protective structure also includes a porous skeleton insulation layer disposed on the outside of the impact-resistant heating layer;

[0024] The porous skeleton insulation layer includes a rigid porous skeleton and thermal insulation material filled in the pores of the rigid porous skeleton, which is used to suppress the heat dissipation of the impact-resistant heating layer to the outside.

[0025] Furthermore, the rigid porous skeleton is an aluminum honeycomb skeleton, and the thermal insulation material is aerogel.

[0026] In this invention, the aerogel densely fills the interior of all the individual cells of the aluminum honeycomb skeleton. The aerogel has extremely low thermal conductivity, simultaneously blocking three heat dissipation paths: heat conduction, air convection, and heat radiation. This effectively suppresses heat dissipation from the impact-resistant heating layer to the outside, ensuring the heating efficiency of the inner heat source on the substrate. Furthermore, the aluminum honeycomb skeleton not only serves as a container for the aerogel but also provides structural support for the insulation layer, preventing the outer layer from collapsing and deforming under ice pressure. Simultaneously, both the aluminum honeycomb skeleton and the aerogel themselves possess elastic compressibility, allowing them to act as a secondary buffer structure during ice floe scraping or impact, assisting in dissipating residual impact loads.

[0027] In this invention, in the porous skeleton insulation layer, the single cell pore size of the aluminum honeycomb skeleton is 3~5mm, the skeleton wall thickness is 1~2mm, the aerogel powder is densely filled inside all the honeycomb single cell cavities, and the overall thickness of the insulation layer is 10~15mm.

[0028] Furthermore, the protective structure also includes a composite fiber protective layer disposed on the outermost side;

[0029] The composite fiber protective layer is made of hybrid fiber reinforced composite material and is used to resist the puncture of outer ice spikes and the scraping load of ice layer, and to act as a sealed protective barrier to prevent corrosive environmental media from penetrating into the inner layer.

[0030] Furthermore, the hybrid fiber reinforced composite material comprises a hybrid braid of carbon fiber and Kevlar fiber.

[0031] In this invention, the composite fiber protective layer is integrally cured and formed by weaving together carbon fiber and Kevlar fiber. Carbon fiber provides in-plane stiffness and compressive strength, while Kevlar fiber provides tear resistance and ice puncture resistance; the two complement each other, avoiding the shortcomings of carbon fiber being brittle and prone to cracking, and Kevlar fiber being insufficient in stiffness.

[0032] This invention places the composite fiber protective layer on the outermost side of the protective structure, directly facing the polar ice, seawater, and ice spike environment. After the woven board is cured and molded as a whole, it forms a dense and airtight protective barrier. On the one hand, it utilizes the high strength and toughness of the hybrid fibers to resist ice spike penetration and ice layer abrasion. On the other hand, it prevents the high salt spray and high dissolved oxygen seawater from penetrating into the inner structure from the source, avoiding the electrochemical corrosion of the substrate caused by the cracking and peeling of conventional anti-corrosion coatings due to freezing heave and abrasion.

[0033] In this invention, the composite fiber protective layer is made by plain weaving carbon fiber and Kevlar fiber in a 1:1 mass ratio and then curing it, with a plate thickness of 12~20mm.

[0034] Furthermore, the protective structure includes a self-sensing functional layer, an impact-resistant heating layer, a porous skeleton insulation layer, and a composite fiber protective layer arranged sequentially. The self-sensing functional layer is located on the inner side, in close contact with the substrate surface of the polar equipment; the composite fiber protective layer is located on the outermost side, directly facing the external environment.

[0035] In this invention, the self-sensing functional layer, the impact-resistant heating layer, the porous skeleton insulation layer, and the composite fiber protective layer are stacked sequentially from the inside to the outside, and adjacent layers are fixedly connected by adhesive to form an integrated prefabricated module. The module is installed on the outside of the substrate by hanging, without the need to cut or weld the substrate.

[0036] This invention sets the protective structure in the form of modular components, which are attached to the outside of the original frame of polar equipment. It can be fixedly installed in key areas such as the waterline and ice zone of icebreakers and research vessels to achieve long-term protection, or it can be quickly disassembled and reassembled in emergency situations such as ships running aground in ice, and reused as temporary protective components.

[0037] Therefore, the present invention achieves active prevention of low-temperature embrittlement by relying on the resource utilization of ship waste heat through the above technical solution. At the same time, it relies on the gradient composite structure of impact-resistant heating layer, self-sensing functional layer, porous skeleton insulation layer and composite fiber protective layer to achieve integrated anti-ice impact, long-term corrosion protection, structural health monitoring and waste heat recovery. One set of components simultaneously solves the three major structural pain points of polar equipment: low-temperature brittle fracture, floating ice impact damage and corrosion failure.

[0038] Furthermore, the protective structure is attached to the outside of the base body by fastening components, which include buckles and fastening bolts. The protective structure is locked and fixed to the frame or prefabricated fixing points of the base body by the buckles and fastening bolts, without the need to cut or weld the base body.

[0039] This invention uses rigid locking buckles and fastening bolts to lock the device to the base frame or prefabricated fixing points. When disassembling, tools are needed to loosen the bolts, making it suitable for long-term fixed installation.

[0040] Furthermore, the protective structure is temporarily secured to the outside of the base body by flexible straps and buckles. After the emergency is resolved, the protective structure can be completely removed, stored, and reused.

[0041] This invention uses a buckle and flexible strapping to wrap around and bind the outer side of the base, allowing for locking and unlocking by hand pressing or pulling, making it suitable for emergency temporary scenarios. The division of labor between these two fastening methods allows the protective structure to flexibly switch installation modes according to working conditions.

[0042] Furthermore, any two adjacent layers among the self-sensing functional layer, the impact-resistant heating layer, the porous skeleton insulation layer, and the composite fiber protective layer are fixed together by adhesive bonding.

[0043] In this invention, the self-sensing functional layer and the impact-resistant heating layer are bonded together with a high-temperature resistant adhesive; the impact-resistant heating layer and the porous skeleton insulation layer are bonded together with a seawater resistant adhesive; and the porous skeleton insulation layer and the composite fiber protective layer are bonded together with an anti-corrosion adhesive.

[0044] Furthermore, when there are multiple protective structures, adjacent protective modules are fixed to each other by connectors, and a sealing structure is provided at the splicing gap to block heat loss and prevent corrosive media from penetrating.

[0045] Compared with existing technologies, the multifunctional composite protective structure for polar equipment with a draped design to prevent low-temperature brittle fracture described in this invention has the following advantages:

[0046] This invention integrates active protection against low-temperature embrittlement, resistance to ice load impact, long-term corrosion protection, structural self-sensing, and waste heat recovery into a single set of hanging modular components. Waste seawater from the generator set is used as a circulating heating medium, flowing into the impact-resistant heating layer channel to continuously conduct heat energy to the substrate, thereby increasing the service temperature and directly eliminating the causes of low-temperature embrittlement from the service environment perspective. A dual energy dissipation mechanism of "solid-liquid coupling" is formed by the plastic crushing of the metal wall and the fluid damping within the porous, sealed channel, effectively attenuating the peak impact load. A composite material layer of carbon fiber and Kevlar hybrid weave serves as the outermost sealed barrier, providing complementary rigidity and toughness to isolate corrosive media at the source. Simultaneously, an internal orthogonal carbon nanotube conductive network acts as a self-sensing functional layer, enabling real-time in-situ monitoring of structural damage and temperature without the need for external sensors. The entire set of components adopts a modular hanging design and is connected to the hull by detachable fasteners. Without fire or cutting, it can be fixedly installed in ice zones for long-term protection, and can also be quickly disassembled and reused in emergency situations such as ice stranding, deck icing, etc., taking into account both conventional protection and emergency rescue needs. Attached Figure Description

[0047] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0048] Figure 1 This is a schematic diagram of the layered structure of the protective structure described in this invention;

[0049] Figure 2 This is a schematic diagram of the protective structure described in this invention installed on the outside of the polar equipment base. Detailed Implementation

[0050] The present invention will be further described below with reference to specific embodiments. First, it should be noted that the data in the following experimental examples were obtained by the inventors through numerous experiments. Due to space limitations, only a portion of these data is shown in the specification, and those skilled in the art can understand and implement the present invention based on this data. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the contents of this invention, those skilled in the art can make various modifications or alterations to the invention, and these modifications or alterations also fall within the scope of protection of this application.

[0051] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0052] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0053] Low-temperature brittle fracture is the most critical of the three challenges. Polar marine environments reach temperatures as low as -30°C to -40°C. These low temperatures significantly degrade the low-temperature toughness and plasticity of marine steel. Even with external loads below the nominal yield strength of the steel, minor compression or instantaneous impact from floating ice can induce brittle cracks in the hull plates. These cracks continue to propagate under alternating ice loads, potentially leading to breaches in the hull plates and water ingress, posing a critical safety hazard for ships navigating in polar regions. Furthermore, the bow and waterline ice zones experience continuous hard impacts and localized compression from bulky ice floes and ice fragments during icebreaking operations. Traditional solid steel reinforced plate structures have limited energy absorption capacity, making them highly susceptible to irreversible structural damage such as hull plate denting and reinforcement buckling under long-term alternating ice loads. Meanwhile, existing ship hulls rely on surface protective coatings for corrosion protection and isolation. However, under the combined effects of alternating high and low temperatures and freezing heave in polar regions, as well as the scraping effect of floating ice, the coating is prone to cracking, powdering, and peeling. The exposed metal substrate undergoes rapid electrochemical corrosion in salty and oxygen-rich seawater, accelerating structural wear.

[0054] like Figures 1-2 As shown, this embodiment provides a multi-functional composite protective structure for polar equipment that is draped to prevent low-temperature brittle fracture. The protective structure is a prefabricated modular plate component that is draped and fixed to the outside of the polar equipment's base.

[0055] The protective structure includes an impact-resistant heating layer, which has a porous closed flow channel for circulating heating medium. The impact-resistant heating layer is provided with a medium inlet and a medium outlet that are connected to the porous closed flow channel for connecting an external heat source pipeline to introduce the circulating heating medium.

[0056] The circulating heating medium is used to conduct heat energy to the inner substrate to increase its service temperature; the circulating heating medium also dissipates impact energy through fluid damping effect when subjected to external impact loads in the porous closed flow channel.

[0057] It should be noted that the polar equipment includes, but is not limited to, polar icebreakers, polar transport ships, marine scientific research drifting stations, small polar workboats, and offshore floating exploration platforms. In theory, this embodiment does not impose strict limitations on the dimensions of the protective structure, and can be customized according to the base area, curvature characteristics, and protection requirements of different equipment. However, considering production efficiency, transportation and installation convenience, and the impact of splicing gaps on insulation and sealing performance, the individual dimensions of the protective structure are: length 1.0m–2.0m, width 0.5m–1.5m, and overall thickness 30mm–60mm.

[0058] In this embodiment, the protective structure further includes a self-sensing functional layer disposed inside the impact-resistant heating layer, the self-sensing functional layer being in close contact with the substrate surface; the self-sensing functional layer includes a conductive network configured to change resistance with temperature changes, structural deformation, or damage, for in-situ monitoring of temperature, structural cracks, local stress, and deformation points; it also includes a porous skeleton insulation layer disposed outside the impact-resistant heating layer, the porous skeleton insulation layer including a rigid porous skeleton and thermal insulation material filling the pores of the rigid porous skeleton, for suppressing heat dissipation of the impact-resistant heating layer to the outside; and it also includes a composite fiber protective layer disposed on the outermost side, the composite fiber protective layer being made of hybrid fiber reinforced composite material, for resisting external ice puncture and ice layer abrasion loads, and acting as a sealed protective barrier to prevent corrosive environmental media from penetrating into the inner layer; the self-sensing functional layer, the impact-resistant heating layer, the porous skeleton insulation layer, and the composite fiber protective layer are arranged sequentially from the inside to the outside.

[0059] It should be noted that this embodiment integrates functions such as active prevention of low-temperature embrittlement, resistance to ice load impact, long-term corrosion protection, structural self-sensing, and waste heat recovery and utilization through the above technical solution, as detailed below:

[0060] (i) Using waste heat to actively heat and eliminate the risk of low-temperature brittleness

[0061] The root cause of cryogenic brittle fracture in polar equipment lies in the sharp decline in the toughness and ductility of metallic materials in frigid environments. Current technologies largely rely on using high-toughness alloys or composite steel plates to passively adapt to low temperatures, but the risk of cryogenic brittle fracture always exists. This embodiment introduces waste heat seawater, which was originally directly discharged into the sea by the generator set, into the internal flow channel of the impact-resistant heating layer. This allows the heat carried by the circulating medium to be continuously conducted to the substrate, transforming passive low-temperature resistance into active temperature regulation. At the same time, the aerogel honeycomb structure in the outer porous skeleton insulation layer utilizes its extremely low thermal conductivity to effectively prevent heat dissipation to the external environment, thereby directly eliminating the embrittlement-inducing factors from the service environment perspective. Furthermore, this solution does not consume additional energy, realizing the resource utilization of waste heat.

[0062] (II) Breaking through the weight increase dilemma of traditional impact-resistant design

[0063] For ice-load impacts, the conventional approach is to increase plate thickness and reinforce the ribs to increase the cross-sectional dimensions and achieve higher load-bearing capacity, but this comes at the cost of a significant increase in the ship's weight. This embodiment utilizes both the plastic crushing of the metal wall and the fluid damping effect of the liquid within the porous, closed flow channels in the impact-resistant heating layer to dissipate impact energy, forming a synergistic mechanism of solid deformation energy absorption + liquid viscosity energy dissipation. Upon impact, the corrugated wall absorbs some energy through its own buckling deformation, while the liquid within the flow channels further weakens the remaining kinetic energy due to inertia-induced damping. The combined effect of these two factors significantly reduces the peak load transmitted to the substrate, with almost no increase in structural weight.

[0064] (III) Integral Fiber Composite Material External Protection

[0065] The challenge of corrosion protection for polar equipment lies in the fact that traditional coatings are easily damaged by the combined effects of low-temperature freeze-thaw cycles and ice abrasion. Once the coating cracks, high-salinity seawater rapidly erodes the base material, quickly eliminating the anti-corrosion effect, resulting in short repair cycles and high costs. This embodiment uses a composite material layer, a woven and integrally cured blend of carbon fiber and Kevlar fiber, as the outermost barrier. Carbon fiber provides in-plane stiffness and compressive strength, while Kevlar fiber provides tear and puncture resistance. The two complement each other to form a dense protective layer that combines rigidity and toughness. This layer serves as both a mechanical protective layer and a physical barrier, preventing corrosive media from contacting the substrate at the source, resulting in a service life far exceeding that of traditional coating systems.

[0066] (iv) Breaking through the traditional external monitoring model

[0067] Health monitoring of ship hull structures typically relies on externally attached strain gauges or periodic manual flaw detection. The former involves a large workload for deployment and maintenance, while the latter is difficult to achieve real-time continuous monitoring. This embodiment integrates an orthogonally arranged carbon nanotube conductive network within the self-sensing functional layer, forming a sensing matrix integrated with the structure. This network is sensitive to both temperature and deformation: temperature changes cause regular shifts in resistance, and structural damage leads to irreversible abrupt changes in local resistance; abnormal locations can be pinpointed through cross-hatching. The structure itself possesses sensing capabilities, enabling real-time online monitoring of temperature, cracks, stress, and deformation without the need for external sensing devices.

[0068] (v) Modular design for quick assembly and disassembly, balancing long-term effectiveness and emergency response.

[0069] Traditional ship hull protection often uses welding for fixing, which is permanent once installed. This method cannot flexibly adjust the coverage area according to the actual damage to the ice zone, nor can it respond quickly in emergency rescue. This embodiment adopts a prefabricated modular design, which is connected to the hull by detachable fasteners such as clips, bolts, or straps. The installation process does not involve open flames or cutting. Under normal working conditions, the module can be fixed in the ice zone for a long time to provide continuous protection; when the ship is ice-stuck and grounded or the deck is covered with ice, it can be quickly attached, disassembled after use, and reused after maintenance. One set of components covers multiple application needs.

[0070] Example 1

[0071] A type of locally fixed protective structure for ice belts along the waterline of polar icebreakers.

[0072] In this embodiment, an integrated protective structure with a single-piece external dimension of 1.0m × 2.0m is prepared. The entire structure is prepared by continuously composite molding of four layers from the inside out.

[0073] The innermost self-sensing functional layer uses a carbon nanotube-modified epoxy resin-based conductive film with a thickness controlled at 0.3 mm. In the processing stage, two sets of independent transverse and longitudinal carbon fiber-based conductive substrates are first prepared. Then, the two substrates are orthogonally stacked at 90° to form a two-dimensional matrix sensing network. The circuit coding terminals are led out at the edge of the film. Subsequently, a heat-resistant epoxy adhesive is used to bond the sensing film as a whole to the inner surface of the subsequent metal corrugated structure, ensuring a tight interface bond without delamination gaps.

[0074] Adjacent to the self-sensing functional layer is an impact-resistant heating layer. The structural base material is marine-grade steel, processed using a roll forming process to create a continuous corrugated structure. The steel plate wall thickness is set at 3mm, and the height of each corrugation after forming is uniformly 30mm. The module is sealed around its perimeter to form a closed, interconnected flow channel within the internal corrugated cavity. Medium inlet and outlet connectors are reserved at the corners of the cavity. During assembly, it is connected to the cooling and drainage pipelines of the ship's engine room diesel generator set via corrosion-resistant hoses, enabling continuous closed-loop circulation of high-temperature seawater within the corrugated cavity after heat exchange by the generator set.

[0075] The outer side of the impact-resistant heating layer is a composite porous skeleton insulation layer. A pre-processed aluminum honeycomb blank with a unit cell diameter of 5mm and a skeleton wall thickness of 1mm is used to densely fill all the honeycomb unit cell cavities, ensuring that there is no missing material in the cavities. The overall thickness of the insulation layer is 12mm, and it is completely composited with the corrugated metal outer plate surface by relying on seawater resistant adhesive.

[0076] The outermost composite fiber protective layer is made of carbon fiber and Kevlar fiber in a 1:1 ratio, woven in a plain weave and cured. After molding, the board is 15mm thick and is then bonded to the outer surface of the honeycomb insulation layer with an anti-corrosion adhesive. After the four layers are bonded, the edges are trimmed to form a neat modular component.

[0077] The on-site assembly process does not require cutting or welding modifications to the original hull side longitudinals, strong ribs, and outer plates. By using matching stainless steel clips and fastening bolts, the draping and locking can be completed along the hull frame points, achieving long-term installation in ice zones.

[0078] The aforementioned protective modules were applied to the waterline ice zone of a polar icebreaker. The vessel continuously broke ice at 3 knots for 4 hours in an ambient temperature of -35°C. The surface temperature of the substrate steadily increased from -33°C (before the modules were applied) to 2°C–5°C, eliminating the risk of low-temperature brittle fracture. Compared to the unapplied area, the peak load on the applied area under the same ice load impact decreased by approximately 45%–55%, and no significant dents or deformations were observed on the substrate surface. After 240 hours of continuous navigation, inspection revealed no signs of corrosion on the substrate surface of the applied area, and the composite fiber protective layer remained intact without any ice puncture damage.

[0079] Example 2

[0080] A temporary emergency protective structure for polar cargo ships stranded due to ice.

[0081] This embodiment is a small emergency protection structure with a size of 0.5m × 1.0m, which is fabricated as an integrated four-layer composite structure.

[0082] The inner self-sensing functional layer uses a 0.5mm thick carbon nanotube composite conductive film. During the molding process, the horizontal and vertical bidirectional sensing circuit matrix is ​​laid out, and after molding, it is bonded to the inner side of the corrugated structure.

[0083] The impact-resistant heating layer is made of marine-grade steel plate with a wall thickness reduced to 2mm. After roll forming, the height of a single corrugation is 20mm, and the cavity is sealed around the perimeter with a pre-reserved medium interface. In the event of ice entrapment, the interface is connected to the ship's auxiliary engine cooling pipeline via a temporary hose, allowing waste seawater from the generator unit to circulate and provide heating within the corrugated cavity.

[0084] The pore size of the honeycomb unit cell in the porous skeleton insulation layer is adjusted to 4mm, and the honeycomb cavity is filled with silica aerogel of the same specification. The insulation layer is tightly bonded to the corrugated structure.

[0085] The outermost composite fiber protective layer uses a 1:1 twill weave process of carbon fiber and Kevlar fiber. After curing and molding, the board thickness is 10mm. It is then bonded to the outer surface of the insulation layer to complete the overall module preparation.

[0086] The on-site emergency assembly method abandons the permanent fastening solution and uses flexible strapping with buckles to temporarily bind the module to the outside of the damaged outer plate of the ship. After the emergency is dealt with, the module can be completely removed and stored. After cleaning and maintenance, the module can be put back into use for subsequent emergency rescue.

[0087] The aforementioned emergency protective structure was attached to the outside of the damaged outer plating of the ice-stuck vessel, and heated by circulating seawater heated by waste heat from the auxiliary engines. Installation took approximately 30 minutes and was easy to assemble and disassemble. After attachment, the temperature of the base material in the damaged area rose from -30°C to above 0°C, thawing the ice layer and providing valuable time for subsequent extrication operations. After the mission was completed, the module was completely removed. After inspection, the structure remained intact, its sealing performance was good, and it was ready for reuse.

[0088] Example 3

[0089] A protective cloak for preventing ice buildup on the deck of a polar scientific research drift station

[0090] In this embodiment, a standardized square protective module with a side length of 1.0m is processed and formed by layering four functional structures.

[0091] The thickness of the inner self-sensing functional layer is set at 0.5mm. The orthogonally arranged carbon nanotube conductive network is integrally formed in the thin film molding process and bonded to the inner surface of the corrugated metal.

[0092] The impact-resistant heating layer is made of marine steel plate with a wall thickness of 3mm, roll-formed into a closed corrugated channel. The cavity is connected to a pipeline to circulate waste heat hot water from the generator set, relying on continuous heat exchange with the water to raise the temperature of the deck substrate.

[0093] The porous skeleton insulation layer has a single cell pore size of 6mm, and the entire honeycomb interior is densely filled with aerogel material. The insulation layer and the corrugated component are integrated into one unit.

[0094] The outermost composite fiber protective layer uses a 1:1 fiber ratio, and after weaving and curing, the board thickness is 10mm. It is bonded to the honeycomb insulation layer to form a complete single module.

[0095] The modules are laid flat on the deck surface of the scientific research rafting station and assembled by using clips along the prefabricated fixing points on the deck, without damaging the original deck base structure.

[0096] The aforementioned protective modules were laid flat and draped over the deck surface of the scientific research rafting station. After circulating hot water from the waste heat of the generator set, the surface temperature of the deck substrate increased from -35℃ (before draping) to 1℃~3℃. After 72 hours of continuous observation, no icing occurred on the deck surface in the draped area; the cumulative ice thickness in the undraped area reached 15mm. The installation and removal process did not require cutting or welding the deck, and the disassembly and assembly time for a single structure did not exceed 30 minutes.

[0097] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A multi-functional composite protective structure for polar equipment, characterized by its draped design to prevent low-temperature brittle fracture, wherein... The protective structure is a prefabricated modular panel component, which is attached and fixed to the outside of the polar equipment base. The protective structure includes an impact-resistant heating layer, which has a porous closed flow channel for circulating heating medium. The impact-resistant heating layer is provided with a medium inlet and a medium outlet that are connected to the porous closed flow channel for connecting an external heat source pipeline to introduce the circulating heating medium. The circulating heating medium is used to conduct heat energy to the inner substrate to increase its service temperature; The circulating heating medium also dissipates impact energy through fluid damping effect when subjected to external impact loads within the porous closed flow channel.

2. The protective structure according to claim 1, characterized in that, The protective structure also includes a self-sensing functional layer disposed inside the impact-resistant heating layer; The self-sensing functional layer includes a conductive network configured to change resistance with temperature, structural deformation, or damage, for in-situ monitoring of temperature, structural cracks, local stress, and deformation points.

3. The protective structure according to claim 2, characterized in that, The conductive network comprises two orthogonally stacked conductive films, which are arranged in the horizontal and vertical directions respectively and have independently led out coded terminals to form a two-dimensional matrix sensing array. The two conductive films are respectively connected to the signal acquisition module. The conductive network is used to sense the temperature distribution and structural state of the protective structure. When the temperature of the monitoring area changes, the resistance of the conductive network changes accordingly according to the thermal resistance effect to achieve temperature monitoring. When the structure is deformed or damaged, the conductive network at the corresponding position is stretched or broken, causing a sudden change in resistance. The deformation or damage coordinates are located by encoding changes.

4. The protective structure according to claim 1, characterized in that, The protective structure also includes a porous skeleton insulation layer disposed on the outside of the impact-resistant heating layer; The porous skeleton insulation layer includes a rigid porous skeleton and thermal insulation material filled in the pores of the rigid porous skeleton, which is used to suppress the heat dissipation of the impact-resistant heating layer to the outside.

5. The protective structure according to claim 4, characterized in that, The rigid porous skeleton is an aluminum honeycomb skeleton, and the thermal insulation material is aerogel.

6. The protective structure according to claim 1, characterized in that, The protective structure also includes a composite fiber protective layer disposed on the outermost side; The composite fiber protective layer is made of hybrid fiber reinforced composite material and is used to resist the puncture of outer ice spikes and the scraping load of ice layer, and to act as a sealed protective barrier to prevent corrosive environmental media from penetrating into the inner layer.

7. The protective structure according to claim 6, characterized in that, The hybrid fiber reinforced composite material comprises a hybrid braid of carbon fiber and Kevlar fiber.

8. The protective structure according to claim 1, characterized in that, The protective structure is attached to the outside of the base body by fastening components, which include buckles and fastening bolts. The protective structure is locked and fixed to the frame or prefabricated fixing points of the base body by the buckles and fastening bolts.

9. The protective structure according to claim 1, characterized in that, The protective structure is temporarily secured to the outside of the base material by flexible straps and buckles.

10. The protective structure according to any one of claims 1 to 9, characterized in that, The self-sensing functional layer, the impact-resistant heating layer, the porous skeleton insulation layer, and the composite fiber protective layer are fixed together by adhesive bonding between any two adjacent layers.

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