Controllable energy-absorbing ch-type corrugated column and aircraft fuselage structure

Abstract

The application discloses a controllable energy-absorbing CH-type corrugated stand column and an aircraft fuselage structure, and belongs to the technical field of aircraft structures. A H-type corrugated section is arranged in the middle section of the CH-type corrugated stand column, and upper and lower ends are C-type connecting sections, which are connected with a floor beam and a fuselage frame through corner pieces, respectively. The aircraft fuselage structure comprises the CH-type corrugated stand column and the fuselage frame, and a plurality of induction openings are arranged at the upper edge strips of the fuselage frame. Through the combined action of the CH-type corrugated stand column and the fuselage frame, a plurality of plastic hinges are generated at the induction openings, so that stable progressive failure of the CH-type corrugated stand column under pressure is ensured, controllable failure and energy absorption stability of the aircraft fuselage frame section are realized, the energy absorption efficiency of the structure and the landing performance are greatly improved, and the problems of uncontrollable deformation of the thin-walled structure of the aircraft fuselage lower opening section and low energy absorption efficiency are solved.

Description

Technical Field

[0001] This invention relates to the field of aircraft structure technology, specifically to a controllable energy-absorbing CH-type corrugated column and an aircraft fuselage structure. Background Technology

[0002] Aircraft crashworthiness, as a key indicator of its safety performance, forms a core design criterion along with structural strength and stiffness. Its core objective is to maximize the safety of the occupants and reduce impact overload during an aircraft crash or emergency landing through controlled structural deformation and energy absorption mechanisms. The subfloor support structure and the main fuselage frame serve as critical energy-absorbing components, and their energy absorption performance has a decisive impact on the overall aircraft crashworthiness. However, current aircraft fuselages often employ open-section thin-walled structural designs. Compared to closed-section tubular components, their asymmetry makes them prone to buckling, bending, and torsion failure modes under impact loads, resulting in significantly insufficient structural energy absorption capacity and failing to effectively dissipate energy, becoming a prominent weakness in improving aircraft crashworthiness.

[0003] Furthermore, aircraft fuselage frame structures often exhibit multi-level, competitive failure characteristics during crashes. Achieving controllable progressive failure and stable energy absorption in open-section structures remains a weak point in domestic and international research. Specifically, two core challenges need to be addressed: first, guiding the open-section fuselage structure to exhibit controllable progressive failure behavior during a crash, avoiding sudden overall destruction; second, guiding the fuselage frame to achieve efficient and stable energy dissipation in a controllable manner by controlling the reasonable failure sequence of open-section column compression failure and open-section fuselage bulkhead bending failure, thereby improving overall energy absorption efficiency. Breakthroughs in these technical challenges are crucial for upgrading aircraft fuselage structure crashworthiness design from passive protection to active, controllable energy absorption.

[0004] Based on this, the present invention proposes a controllable energy-absorbing CH-type corrugated column and an aircraft fuselage structure. Through configuration innovation and collaborative design of failure paths, it overcomes the defects of low energy absorption efficiency and uncontrollable deformation mode of traditional open-section thin-walled structures, and provides an effective technical solution for improving aircraft crash safety. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a controllable energy-absorbing CH-type corrugated column and fuselage structure. By cooperating with the progressive crushing of the CH-type corrugated column and the plastic hinge formed by the induction port of the fuselage frame, the failure mode of the fuselage frame segment is controllable and the energy absorption process is stable.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] The present invention provides a first solution: a controllable energy-absorbing CH-type corrugated column, wherein the middle section of the CH-type corrugated column is provided with an H-shaped corrugated section, the corrugation of the corrugated section extends along its length, and at both ends of the corrugated section are respectively provided a C-shaped crossbeam connecting section and a fuselage frame connecting section, the crossbeam connecting section is connected to the floor crossbeam through corner pieces, and the fuselage frame connecting section is connected to the fuselage frame through corner pieces.

[0008] In a preferred embodiment of the present invention, the cross-sections of the beam connecting section and the fuselage frame connecting section are both C-shaped, and the web and flange of the C-shaped section are both flat plate structures. Furthermore, multiple openings for connecting corner pieces are provided on the web and flange of the beam connecting section and the fuselage frame connecting section.

[0009] In a preferred embodiment of the present invention, along the height direction of the CH-shaped corrugated column, the flange width of the upper C-shaped crossbeam connecting section is greater than the flange width of the lower C-shaped fuselage frame connecting section.

[0010] In a preferred embodiment of the present invention, the web and flange of the corrugated section are both longitudinal corrugated structures, and the corrugation direction extends along the length direction of the CH-type corrugated column.

[0011] In a preferred embodiment of the present invention, the flange of the corrugated section has a gradually changing width structure, with the flange width near the end of the crossbeam connecting section being greater than the flange width near the end of the fuselage frame connecting section, forming a width decreasing feature from top to bottom.

[0012] The present invention provides a second solution: an aircraft fuselage structure, including CH-type corrugated columns.

[0013] In a preferred embodiment of the present invention, the aircraft fuselage structure further includes a skin, several stringers, a fuselage bulkhead, and a floor beam. Several stringers are equidistantly arranged on the lower side of the fuselage bulkhead, and the skin covers the outer surface of the stringers. The fuselage bulkhead is an arc-shaped structure and is connected to the horizontally arranged floor beam through CH-shaped corrugated columns to form a lower fuselage structural frame with controllable energy absorption function.

[0014] In a preferred embodiment of the present invention, the fuselage frame includes a fuselage frame body. A first induction port, a second induction port, a third induction port, and a fourth induction port are provided on the upper edge strip of the fuselage frame body. The first induction port is located at the bottom of the fuselage frame body. Two second induction ports are symmetrically distributed on both sides of the first induction port. Two third induction ports are symmetrically distributed on the outside of the second induction port. Two fourth induction ports are symmetrically distributed on the outside of the third induction port, forming an induction port distribution sequence from bottom to top or from center to both sides.

[0015] In a preferred embodiment of the present invention, the size of the first induction port is larger than the size of the second induction port; the size of the second induction port is larger than the size of the third induction port; and the size of the third induction port is larger than the size of the fourth induction port.

[0016] In a preferred embodiment of the present invention, the CH-type corrugated columns are evenly distributed and symmetrically distributed among the first induction port, the second induction port, the third induction port and the fourth induction port.

[0017] Compared with the prior art, the present invention provides a controllable energy-absorbing CH-type corrugated column and an aircraft fuselage structure, which has the following beneficial effects:

[0018] 1. Structural stability and energy absorption efficiency are significantly improved;

[0019] By combining the C-shaped sections at both ends of the CH-type corrugated column with the H-shaped corrugated area in the middle, the stability of the open-section column under axial compression is effectively improved. This structure can guide the column to produce controllable progressive failure behavior during the crushing process, achieving step-by-step collapse starting from the corrugated area, avoiding the sudden overall instability of traditional vertical columns, thereby significantly improving the efficiency and controllability of energy absorption.

[0020] 2. Enhanced buckling delay and plastic energy dissipation capacity;

[0021] The longitudinal corrugated structure and gradually widened flange design in the H-shaped corrugated area further optimize the mechanical properties of the column. The corrugated configuration delays the occurrence of local buckling, while the gradually widened flange effectively disperses stress concentration, making the crushing process smoother, extending the plateau period of the load-displacement curve, and improving the structure's plastic deformation capacity and energy dissipation uniformity.

[0022] 3. Improved controllability of failure paths and synergy between deformation modes;

[0023] The H-shaped corrugated area provides a clear buckling guidance path for the structure, ensuring that the columns collapse in stages according to a preset pattern under pressure. Combined with the induction port design at the upper edge of the fuselage bulkhead, multiple plastic hinges can be triggered sequentially under impact loads, forming a "soft-then-hard" response mechanism. This mechanism absorbs energy and reduces the peak acceleration of the cabin through local yielding in the early stages of impact, and maintains overall support through the remaining structure in the later stages, ensuring the survival space for the occupants.

[0024] 4. Overall optimization of system-level energy absorption and fall adaptability;

[0025] The progressive crushing of the CH-shaped corrugated columns and the orderly bending deformation of the fuselage bulkhead work together to form a multi-stage energy dissipation path. This integrated design achieves matching between the failure sequence and spatial deformation of the columns and bulkhead, enabling the lower fuselage structure to exhibit higher energy absorption stability and overall crashworthiness under crash conditions, thereby comprehensively improving the aircraft's crashworthiness. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the aircraft fuselage of the present invention.

[0027] Figure 2 This is a schematic diagram of the CH-type corrugated column of the present invention.

[0028] Figure 3 This is a structural diagram of the CH-type corrugated column of the present invention.

[0029] Figure 4 This is a schematic diagram of the corner piece of the present invention.

[0030] Figure 5 This is a schematic diagram of the main body of the fuselage frame of the present invention.

[0031] Figure 6 This is a schematic diagram of the guide port of the main body frame of the present invention.

[0032] Figure 7 This is a diagram illustrating the failure process of the CH-type column of the present invention under axial compression conditions.

[0033] Figure 8 This is a schematic diagram of the straight C-column structure compared to the present invention.

[0034] Figure 9 This is a diagram illustrating the crushing failure process of a straight C-column as compared in this invention.

[0035] Figure 10 The load-displacement curves of the CH-type corrugated column and the straight C-type column of this invention are shown.

[0036] In the diagram: 1. Skin; 2. Truss; 3. Corrugated column; 31. H-shaped corrugated area; 32. Crossbeam connection section; 33. Fuselage frame connection section; 4. Corner plate; 41. Corner plate web; 411. Bolt hole one; 42. Corner plate flange; 421. Bolt hole two; 5. Fuselage frame; 51. Fuselage frame main body; 52. First guide port; 53. Second guide port; 54. Third guide port; 55. Fourth guide port; 6. Floor crossbeam. Detailed Implementation

[0037] This invention provides a controllable energy-absorbing CH-type corrugated column and an aircraft fuselage structure. The specific embodiments of this invention are described below with reference to the accompanying drawings.

[0038] Aircraft crashworthiness, as a key indicator of its safety performance, is considered a core design criterion alongside structural strength and stiffness. Its core objective is to maximize occupant safety during crashes or emergency landings by reducing impact loads to minimize casualties. Key energy-absorbing components, such as the subfloor pillars and fuselage bulkheads, absorb impact energy to buffer loads and are crucial for improving crashworthiness. However, current aircraft fuselage structures often employ open-section, thin-walled designs. Compared to closed-section tubular components, their asymmetry makes them susceptible to overall failure modes such as buckling, bending, torsion, or sudden fracture under impact loads. This results in significantly insufficient energy absorption capacity, failing to effectively dissipate energy and becoming a prominent weakness in improving crashworthiness.

[0039] Especially under complex operating conditions where aircraft fuselages exhibit multiple competing failure paths such as column compression and bulkhead bending, achieving controllable progressive failure of open-section structures and coordinating the failure sequence among different components to form an efficient and collaborative energy absorption mechanism remains a critical technical challenge in the field of crashworthiness design. Specifically, two key issues need to be addressed: first, guiding the open-section columns to form a stable progressive crushing mode to avoid sudden overall instability; and second, coordinating the temporal relationship between column compression failure and bulkhead bending failure to achieve orderly energy dissipation of the fuselage frame segments.

[0040] To address the aforementioned problems, this invention provides a controllable energy-absorbing CH-type corrugated column and an aircraft fuselage structure. This structure, through the progressive crushing characteristics of the CH-type corrugated column combined with the induction port design of the fuselage bulkhead, allows multiple plastic hinges to form sequentially at the induction ports on the fuselage bulkhead under impact loads. Simultaneously, the CH-type corrugated column undergoes stable progressive crushing. The synergistic action of both achieves controllable failure modes and stable energy absorption processes for the entire fuselage frame segment. Compared to traditional metal or composite material fuselage frame structures, this significantly improves energy absorption efficiency and crashworthiness.

[0041] Example 1:

[0042] Please see Figures 1-4 As shown, this embodiment provides a controllable energy-absorbing CH-type corrugated column 3. The CH-type corrugated column 3 is configured between the aircraft fuselage frame 5 and the floor beam 6. An H-shaped corrugated section 31 is provided in the middle section of the CH-type corrugated column 3. The corrugation of the corrugated section 31 extends along its length. A beam connecting section 32 and a fuselage frame connecting section 33 are respectively provided at both ends of the corrugated section 31. The beam connecting section 32 is detachably connected to the floor beam 6 through corner pieces 4. The fuselage frame connecting section 33 is detachably connected to the fuselage frame 5 through corner pieces 4. Both the beam connecting section 32 and the fuselage frame connecting section 33 are C-shaped structures.

[0043] In this embodiment, the combined design of the C-shaped cross-sections at both ends and the H-shaped cross-section in the middle of the CH-type corrugated column 3 significantly improves the axial compressive stability of the CH-type corrugated column 3, enabling it to undergo controllable progressive crushing during the crush failure process, thereby efficiently absorbing impact kinetic energy and ensuring energy absorption efficiency. The corrugated section 31 in the middle provides a guiding path for initial buckling, causing the corrugated section 31 to collapse step by step along a preset path when the column is compressed, effectively avoiding the problem of sudden overall breakage caused by local strong buckling of traditional vertical columns, and achieving a stable and controllable energy absorption effect.

[0044] As a further optimization, in the embodiments of this disclosure, such as Figure 2 and Figure 3 As shown, the web and flange of the beam connecting section 32 and the fuselage frame connecting section 33 are both flat plate structures, and multiple openings for connecting corner pieces 4 are provided on the web and flange of the beam connecting section 32 and the fuselage frame connecting section 33, so as to facilitate the installation and fixing of the CH-type corrugated column 3 through the openings on the web and flange of the beam connecting section 32 and the fuselage frame connecting section 33.

[0045] In this embodiment, the aforementioned crossbeam connection section 32 and fuselage frame connection section 33 adopt a flat plate structure web and flange design, which can fit well with the surface of the C-shaped corner piece 4, effectively improving the fit and load-bearing stability of the connection parts; at the same time, the openings on the web and flange provide precise positioning for the connection of the corner piece 4, reducing the installation difficulty, and further ensuring the connection reliability of the CH-shaped corrugated column 3 during the impact process, thereby assisting in achieving controllable progressive failure and stable energy absorption functions.

[0046] As a further optimization, in this embodiment, along the height direction of the CH-shaped corrugated column 3, the width of the flange of the upper beam connecting section 32 is greater than the width of the flange of the lower fuselage frame connecting section 33; wherein, the beam connecting section 32 is detachably connected to the floor beam 6 through corner pieces 4, and the fuselage frame connecting section 33 is detachably connected to the fuselage frame 5 through corner pieces 4, and both of their webs and flanges are flat structures with connection openings.

[0047] In this embodiment, the aforementioned crossbeam connection section 32 adopts a wider flange design, which can effectively improve its connection strength and load-bearing stability with the floor crossbeam 6, meeting the requirement of greater load dispersion at the upper connection part during a crash. Meanwhile, the relatively narrow flange width of the fuselage frame connection section 33 helps to guide the area to undergo controllable deformation according to a preset pattern during the crash, avoiding sudden failure caused by local stress concentration. This, in conjunction with the gradual collapse of the central corrugated section 31, works together to achieve the goal of controllable progressive failure of the fuselage structure and stable energy absorption.

[0048] As a further optimization, in the embodiments of this disclosure, such as Figure 2 and Figure 3 As shown, the web and flange of the corrugated section 31 are both longitudinal corrugated structures, and the corrugation direction extends along the length direction of the CH-shaped corrugated column 3. At the same time, the flange of the corrugated section 31 has a gradually changing width design. The flange width near the end of the crossbeam connecting section 32 is greater than the flange width near the end of the fuselage frame connecting section 33, forming a width decreasing feature from top to bottom.

[0049] In this embodiment, the aforementioned longitudinal corrugated web structure provides a guiding path for the initial buckling of the corrugated section 31, enabling it to undergo controllable, stepwise compression along the corrugation direction under pressure, thus avoiding sudden overall buckling. The gradually changing width design of the flange further optimizes the load distribution—the wider flange near the crossbeam connection section 32 enhances the upper connection strength, meeting the large load transfer requirements in the initial stage of the impact; the narrower flange near the fuselage frame connection section 33 guides this area to deform preferentially, working in synergy with the compression of the central corrugated web to ensure that the CH-type corrugated column 3 absorbs the impact kinetic energy in a gradual and stable manner, thereby effectively improving the crashworthiness of the fuselage structure.

[0050] As a further optimization, in the embodiments of this disclosure, such as Figure 4 As shown, the corner pieces 4 are symmetrically arranged at both ends of the CH-shaped corrugated column 3, including the corner piece web 41 and the corner piece flanges 42 symmetrically connected on both sides, forming a C-shaped cross-section structure; wherein, the corner piece web 41 is provided with multiple bolt holes 411, and the two corner piece flanges 42 are provided with multiple bolt holes 421 respectively. The distribution positions of the bolt holes 411 and bolt holes 421 correspond completely to the connection openings (such as the aforementioned web and flange openings) on the crossbeam connection section 32 and the fuselage frame connection section 33 of the CH-shaped corrugated column 3.

[0051] In this embodiment, the corner piece 4 is aligned with the connection opening of the CH-type corrugated column 3 through bolt hole 411 and bolt hole 421, and a detachable connection is achieved by bolts. The crossbeam connection section 32 is firmly fixed to the floor crossbeam 6, and the fuselage frame connection section 33 is firmly fixed to the fuselage frame 5. Its C-shaped cross-section structure is closely fitted with the C-shaped connection section surface at both ends of the CH-type corrugated column 3, which effectively improves the load-bearing stability and load transfer efficiency of the connection part, ensures that the large load can be evenly distributed during the impact, avoids local stress concentration, and thus provides a reliable connection guarantee for the CH-type corrugated column 3 to achieve controllable progressive failure and stable energy absorption.

[0052] As a further optimization, in the embodiments of this disclosure, such as Figure 1 , Figure 2 and Figure 3As shown, the CH-type corrugated column 3 is made of metal or metal-composite materials and is manufactured by an integral molding process (such as integral machining, hot pressing, etc.).

[0053] In this embodiment, the one-piece molding process can effectively ensure the material continuity and structural integrity of the CH-type corrugated column 3, avoiding local stress concentration and weak points caused by welding or mechanical connection; especially for the C-type connection sections at both ends (the crossbeam connection section 32 and the fuselage frame connection section 33), the one-piece molding process can significantly improve its fracture resistance, ensuring that this area will not experience sudden fracture failure or delamination failure due to large load impact during the impact, thereby providing structural reliability guarantee for the column to achieve controllable progressive crushing and stable energy absorption.

[0054] Example 2:

[0055] Please see Figures 1-5 As shown, unlike Embodiment 1 above, this embodiment provides an aircraft fuselage structure, which is the lower structure of the aircraft. In addition to the CH-type corrugated columns 3 and corner pieces 4 as described in Embodiment 1, it also includes a skin 1, several stringers 2, a fuselage frame 5, and a floor beam 6. The stringers 2 are equidistantly arranged on the lower side of the fuselage frame 5 and are fixedly connected to the fuselage frame 5. They are used to fix the skin 1 and transfer the load. The skin 1 covers the outer surface of the stringers 2 and, together with the stringers 2, bears the initial impact load and transfers it to the fuselage frame 5. The fuselage frame 5 is an arc-shaped structure and is connected to the horizontally arranged floor beam 6 through the CH-type corrugated columns 3 to form a lower fuselage structure frame with controllable energy absorption function.

[0056] In this embodiment, through the aforementioned aircraft fuselage structure design, in the event of a survivable crash, the impact load is first transmitted to the structural system from the bottom skin 1. The skin 1 and stringer 2 jointly bear the initial load and transfer it to the fuselage bulkhead 5, which is then further applied to the CH-shaped corrugated column 3 connected to it. Because the two ends of the CH-shaped corrugated column 3 are firmly fixed to the floor beam 6 and fuselage bulkhead 5 via the crossbeam connection section 32 and the fuselage bulkhead connection section 33, the overall structure forms a double-end constraint under axial load, causing the corrugated section 31 in the middle of the column to preferentially buckle locally. Guided by the corrugated design and the gradually changing flange width structure design, the CH-shaped corrugated column 3 undergoes multi-stage progressive collapse along the axial direction, gradually releasing the impact energy and significantly reducing the instantaneous overload peak value.

[0057] As a further optimization, in the embodiments of this disclosure, such as Figure 5 and Figure 6As shown, the fuselage frame 5 includes a fuselage frame body 51, which has a Z-shaped, C-shaped or other cross-section and participates in the connection of the lower fuselage structure. The fuselage frame body 51 is also provided with a first guide port 52, a second guide port 53, a third guide port 54 and a fourth guide port 55. The first guide port 52 is located at the bottom of the fuselage frame body 51. The two second guide ports 53 are symmetrically distributed on both sides of the first guide port 52. The two third guide ports 54 are symmetrically distributed on the outside of the second guide ports 53. The two fourth guide ports 55 are symmetrically distributed on the outside of the third guide ports 54 (along the circumferential extension direction of the fuselage frame body 51), forming a guide port distribution sequence from bottom to top or from center to both sides.

[0058] In this embodiment, in the above structure, through the optimized design of the induction port position, when the fuselage bulkhead 5 is subjected to impact load, it can form plastic hinges at the induction port position in sequence according to a preset path: initially, the first induction port 52 and the adjacent area preferentially undergo yielding or plastic deformation, absorbing part of the impact energy and reducing the peak acceleration transmitted to the cabin; as the load increases, the second induction port 53, the third induction port 54, and the fourth induction port 55 successively enter the plastic deformation stage, realizing a "soft first, hard later" response mechanism—efficiently dissipating energy through local plastic deformation in the early stage, and strengthening the overall support through the remaining structural strength in the later stage, thus delaying the overall failure process, thereby effectively protecting the integrity of the occupant space and improving the crashworthiness performance of the fuselage structure.

[0059] As a further optimization, in this embodiment, the size and area of ​​the first induction port 52 are greater than the size and area of ​​the second induction port 53; the size and area of ​​the second induction port 53 are greater than the size and area of ​​the third induction port 54; and the size and area of ​​the third induction port 54 are greater than the size and area of ​​the fourth induction port 55. The size and area of ​​the first induction port 52, the second induction port 53, the third induction port 54, and the fourth induction port 55 decrease sequentially, while the bending stiffness and strength increase sequentially.

[0060] In this embodiment, the aforementioned design of decreasing size and increasing stiffness enables the fuselage bulkhead 5 to form a "soft-then-hard" response mechanism under impact load: initially, the largest first induction port 52 and its adjacent area undergo plastic deformation due to their lower stiffness, absorbing impact energy and reducing the peak acceleration transmitted to the cabin; as the load increases, the smaller second induction port 53, third induction port 54, and fourth induction port 55 successively enter the plastic deformation stage. At this time, the areas with higher stiffness begin to bear the load, enhancing the overall support capacity, delaying the overall structural failure process, thereby effectively protecting the integrity of the occupant space, and achieving a controllable bending failure sequence and efficient energy dissipation.

[0061] As a further optimization, in this embodiment, the CH-shaped corrugated columns 3 are evenly and symmetrically distributed among the first guide port 52, the second guide port 53, the third guide port 54, and the fourth guide port 55. Simultaneously, they are connected to the fuselage frame 51 and the floor beam 6 via corner pieces 4 and bolts, forming a column layout that coordinates with the distribution of the guide ports. The bolts do not fail during the impact.

[0062] In this embodiment, during connection, the crossbeam connection section 32 of the CH-type corrugated column 3 is detachably connected to the floor crossbeam 6 via corner pieces 4, and the fuselage frame connection section 33 is detachably connected to the fuselage frame 51 via corner pieces 4. The connection uses high-strength bolts and optimizes the bolt specifications and preload to ensure that the bolts do not break or fail during the impact process, thereby ensuring the connection reliability of the overall structure under load and providing a stable connection guarantee for the CH-type corrugated column 3 to achieve controllable progressive crushing and efficient energy absorption.

[0063] Example 3:

[0064] Please see Figures 6-10 As shown, unlike the above embodiments, this embodiment verifies the compressive stability and energy absorption effect of the CH-type corrugated column 3 described in Embodiment 1 and the aircraft fuselage structure described in Embodiment 2 through axial compression simulation.

[0065] This embodiment first performs an axial compression simulation of the CH-type corrugated column under a loading rate of 1 m / s. The simulation results are as follows: Figure 7 , Figure 9 and Figure 10 As shown. Wherein:

[0066] (1) The failure process of CH-type corrugated column 3 (material is aluminum alloy) under axial compression is as follows Figure 7 As shown, with the increase of compressive displacement, the CH-type corrugated column 3 buckles sequentially from the bottom corrugation, gradually extending upwards, exhibiting a complete failure process from initial local buckling to progressive collapse of the corrugated area. In the 10mm to 40mm stage, buckling is mainly concentrated in the corrugated area, manifested as local bulging and collapse; in the 60mm to 80mm stage, local instability continues to expand and propagate to other parts of the structure; at 125mm, the structure undergoes significant twisting and folding, with the corrugated sections squeezing each other, and the internal voids of the structure being compacted, resulting in a typical densification effect.

[0067] (2) In contrast, Figure 9The crush failure process of a conventional straight C-column under the same working conditions is demonstrated. When the crush displacement of the straight C-column is 10 mm, the C-column undergoes slight deformation, mainly manifested as local bending. Subsequently, at a displacement of 20 mm, cracks appear at the bending point of the C-column. After a crush displacement of 40 mm, the deformation becomes more severe, leading to local failure and eventually complete structural failure. Compared to the straight C-column, the CH-type corrugated column 3 exhibits progressive crush failure, thus absorbing more energy.

[0068] (3) Figure 10 The load-displacement curves for the CH-type corrugated column 3 and the straight C-type column are shown. The initial peak loads of the CH-type corrugated column and the straight C-type column are 31.47 kN and 51.75 kN, respectively, and the average crushing loads are 64.24 kN and 8.09 kN, respectively. The comparison reveals that the CH-type corrugated column 3 not only reduces the initial peak load but also increases the average load, demonstrating its superior mechanical response during axial compression. The load-displacement curve of the CH-type corrugated column exhibits a multi-peak fluctuating upward pattern, reflecting its good progressive energy absorption characteristics. In the initial stage (0-20 mm), the load slowly rises to 30 kN, then decreases slightly, indicating initial local instability. In the subsequent displacement range of 20-110 mm, the curve shows multiple peak-valley fluctuations, with local peaks appearing at 26 mm, 57 mm, and 90 mm, corresponding to the sequential buckling and collapse of each corrugation, demonstrating the good deformation coordination and stability of the structure during crushing. Finally, after 110mm, the curve shows a significant upward trend (exceeding 220kN), reflecting that the internal structure has become compacted and the corrugated structure has been completely compressed.

[0069] The results above show that the CH-type corrugated column 3, through the introduction of longitudinal corrugated webs and the H-shaped middle section design with gradually changing flanges, can effectively delay local buckling under compressive loads and guide the structure to produce multi-stage collapse. The load-displacement curve shows a multi-peak fluctuating upward trend, which is significantly different from the single-peak instability characteristics of traditional straight C-columns. Compared to the straight C-column (which exhibits significant fracture at a crush stroke of 20 mm, rapid instability leading to overall failure after 40 mm, lacks a transition buffer stage, and has low structural energy absorption efficiency), the CH-type corrugated column 3 exhibits multiple buckling modes in the axial compression simulation failure morphology, with a smooth overall deformation process and no sudden fracture; the average crush load is 64.24 kN, far exceeding that of the straight C-column (8.09 kN); the straight C-column absorbs 1012.94 J of energy, while the CH-type corrugated column absorbs 8025.65 J, demonstrating a significant improvement in energy absorption capacity (area under the load-displacement curve); the initial peak load is reduced by 39.2% (from 51.75 kN to 31.47 kN), which helps mitigate the initial impact injury to occupants; the overall load-displacement curve shows an upward fluctuation, reflecting the structure's excellent progressive crush performance.

[0070] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An aircraft fuselage structure, characterized in that, Including CH-type corrugated columns (3); The middle section of the CH-type corrugated column (3) is provided with an H-type corrugated section (31). The corrugation of the corrugated section (31) extends along its length. At both ends of the corrugated section (31), there are C-type crossbeam connecting sections (32) and fuselage frame connecting sections (33). The crossbeam connecting section (32) is connected to the floor crossbeam (6) through corner pieces (4). The fuselage frame connecting section (33) is connected to the fuselage frame (5) through corner pieces (4). The web and flange of the corrugated section (31) are both longitudinal corrugated structures, and the corrugation direction extends along the length direction of the CH-type corrugated column (3). The flange of the corrugated section (31) has a gradually changing width structure. The flange width at the end near the crossbeam connecting section (32) is greater than the flange width at the end near the fuselage frame connecting section (33), forming a width decreasing feature from top to bottom. It also includes a skin (1), several long trusses (2), a fuselage frame (5) and a floor beam (6). Several of the long trusses (2) are equidistantly arranged on the lower side of the fuselage frame (5), and the skin (1) covers the outer surface of the long trusses (2). The fuselage frame (5) is an arc-shaped structure and is connected to the horizontally arranged floor beam (6) through CH-type corrugated columns (3) to form a lower fuselage structure with controllable deformation and stable energy absorption function. The fuselage frame (5) includes a fuselage frame body (51). The upper edge of the fuselage frame body (51) is provided with a first induction port (52), a second induction port (53), a third induction port (54) and a fourth induction port (55). The first induction port (52) is located at the bottom of the fuselage frame body (51). The two second induction ports (53) are symmetrically distributed on both sides of the first induction port (52). The two third induction ports (54) are symmetrically distributed on the outside of the second induction ports (53). The two fourth induction ports (55) are symmetrically distributed on the outside of the third induction ports (54), forming an induction port distribution sequence from bottom to top or from center to both sides. The size of the first induction port (52) is larger than the size of the second induction port (53); the size of the second induction port (53) is larger than the size of the third induction port (54); the size of the third induction port (54) is larger than the size of the fourth induction port (55).

2. The aircraft fuselage structure as described in claim 1, characterized in that, The CH-type corrugated columns (3) are evenly distributed and symmetrically distributed among the first induction port (52), the second induction port (53), the third induction port (54), and the fourth induction port (55).

3. The aircraft fuselage structure as described in claim 1, characterized in that, The cross-sections of the beam connecting section (32) and the fuselage frame connecting section (33) are both C-shaped, and the web and flange of the C-shaped section are both flat structures. Multiple openings for connecting corner pieces (4) are provided on the web and flange of the beam connecting section (32) and the fuselage frame connecting section (33).

4. An aircraft fuselage structure as described in claim 3, characterized in that, Along the height direction of the CH-type corrugated column (3), the width of the flange of the upper C-type crossbeam connecting section (32) is greater than the width of the flange of the lower C-type fuselage frame connecting section (33).

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