Explosion-proof wall for offshore platform honeycomb core

Abstract

The application discloses a kind of ocean platform honeycomb core layer blast wall, its basic structure includes: first wallboard, vertically sheltered in the first side of protected object;Second wallboard, vertical sheltering in the second side of protected object, the second side with the first side is adjacent side;Correspondingly, the first wallboard and the second wallboard are fixedly connected as a whole at the adjacent end portion between each other vertically;The first wallboard and the second wallboard include front panel located outside relative to protected object and rear panel located inside, and honeycomb core layer between front panel and rear panel. According to the ocean platform honeycomb core layer blast wall of the application, the protection performance is relatively better.

Description

TECHNICAL FIELD

[0001] The present application relates to a honeycomb core blast wall of an offshore platform. BACKGROUND

[0002] An offshore platform is an important facility for exploiting and storing oil and gas resources at sea. Since it serves in the marine environment, the electrical equipment, oil and gas processing equipment and oil and gas storage equipment on the platform must be compactly arranged in a limited space. Once an oil and gas leakage accident occurs, an explosion accident may occur on the jacket platform, which will seriously threaten the safety of the equipment and personnel on the platform. As an important protective facility of the offshore platform, the blast wall is widely used in resisting explosion.

[0003] Further, in the long-term operation of oil and gas exploration, the jacket platform at sea is often encountered with unexpected events such as accidental explosion caused by gas leakage and fire caused by hydrocarbons. Due to the great overpressure caused by explosion, the explosion accident may cause damage to the platform structure or oil and gas equipment, thereby causing huge losses and even endangering the safety of personnel. Therefore, various explosion-proof measures should be taken to protect the key equipment from the influence of explosion load. Among them, the blast wall can effectively absorb explosion energy and reflect explosion pressure wave, and has the advantages of low cost, quick installation and high strength, and is widely used in offshore platform structures to become a protective barrier to ensure the safety of platform structures and personnel.

[0004] The corrugated plate blast wall, as a commonly used explosion-proof barrier, has been widely used in marine structures. Scholars have studied the structural response and explosion resistance of the blast wall by numerical simulation and experimental methods. Kang et al. simulated the influence of different loads on the blast wall by CFD and compared the dynamic response of the blast wall. Syed et al. used nonlinear finite element analysis method to give the real response of various high-impact pressure loads generated by oil and gas explosion, and compared with the test. Su et al. simulated the propagation of explosion shock wave by using finite element software LS-DYNA and compared with the test, and obtained the propagation law of shock wave. However, some scholars pointed out that in the actual blast design process, the existing corrugated plate blast wall structure underestimated the real influence of explosion load, which would lead to a greater risk of damage to the protected structure.

[0005] At present, the honeycomb structure is widely used in various industries for safety protection due to its excellent energy absorption capacity. The honeycomb core structure combines the honeycomb core and two high-strength laminates together, so as to have the comprehensive advantages of the stiffness and strength of the two. Therefore, if a sandwich blast wall with different honeycomb cores is designed, a more superior explosion resistance performance can be obtained for explosion load.

[0006] The honeycomb structure is an internal organizational structure of the sandwich blast wall, so as to improve the rigidity and strength of the single blast wall. Typically, as disclosed in Chinese patent document CN112049321A, a honeycomb sandwich blast wall plate includes two layers of steel plates arranged in parallel and a honeycomb composite layer located between the two layers of steel plates, so as to form a three-layer structure, and the three-layer structure is connected by connecting components. In use, the wall plate is installed in a vertical manner. It is found through research that when the shock wave generated by the explosion point acts on the blast wall, the blast wall will deform, and the specific performance is that, for example, for a single-point explosion, the blast wall will produce an inward concave at a position approximately perpendicular to the explosion point, but the maximum deformation does not necessarily occur at this position. The inward concave is the result of the blast wall resisting deformation, and the remaining part will also be impacted. Since the shock wave first collides with the final inward concave, the remaining part is subjected to a combined impact due to the impact and pulling of the remaining part. In addition to the connecting part with the platform, the blast wall lacks other parts to suppress, so the impact resistance of the blast wall is relatively weak. SUMMARY

[0007] The purpose of the present application is to provide a marine platform honeycomb core blast wall with relatively better protection performance.

[0008] In an embodiment of the present application, a marine platform honeycomb core blast wall is provided, which has a basic structure including:

[0009] A first wall plate vertically shielding a first side of the protected object;

[0010] A second wall plate vertically shielding a second side of the protected object, which is an adjacent side to the first side. Correspondingly, the first wall plate and the second wall plate are fixedly connected at the adjacent end portions to form an integrated structure.

[0011] The first wall plate and the second wall plate each include a front panel located on the outer side relative to the protected object and a rear panel located on the inner side, and a honeycomb core layer located between the front panel and the rear panel.

[0012] Optionally, the first wall plate and the second wall plate are connected at a right angle or connected through a rounded corner transition.

[0013] Optionally, if the first wall plate and the second wall plate are connected at a right angle, the first wall plate and the second wall plate have:

[0014] A first connection mode in which one end portion of the second wall plate abuts against a corresponding end side surface of the first wall plate, and the front and rear panels of the second wall plate are welded or connected by angle bars or flanged rivets or bolts with the rear panel of the first wall plate;

[0015] The second connecting mode is that the second wall plate and the front wall plates of the first wall plate are integrally bent plates or fixed connections, and the rear wall plates are integrally bent plates or fixed connections; the fixed connection mode is welding or riveting or bolt connection through angle bars or flanges;

[0016] If the first wall plate and the second wall plate are connected through a circular arc transition, and at least the corresponding two front wall plates are connected through a circular arc transition, the first wall plate and the second wall plate have:

[0017] The third connecting mode is that the corresponding two front wall plates are integrally bent to form a front circular arc transition part; if the rear wall plates are also connected through a circular arc transition, the corresponding two rear wall plates are integrally bent to form a rear circular arc transition part.

[0018] The fourth connecting mode is that the corresponding two front wall plates are fixedly connected through front circular arc transition pieces; if the rear wall plates are also connected through a circular arc transition, the corresponding two rear wall plates are fixedly connected through rear circular arc transition pieces.

[0019] Optionally, the radius of the outer circular arc transition part or the outer circular arc transition piece is 0.9-1.5 times the thickness of the honeycomb core layer.

[0020] Optionally, in the second to fourth connecting modes, the two honeycomb core layers are continuous honeycomb core layers.

[0021] Optionally, the honeycomb core layer is an inner concave arc-shaped honeycomb core layer.

[0022] Optionally, the number of layers of the honeycomb core layer is 4-7, and the thickness is 0.16-0.28 m.

[0023] Optionally, the honeycomb cells in the inner concave arc-shaped honeycomb core layer are inner concave honeycomb cells, the inner concave angle of the inner concave honeycomb cell is 40-50 degrees, and the width-height ratio is 0.9-1.3.

[0024] Optionally, the inner concave angle is 45 degrees, and the width-height ratio is 1.1.

[0025] Optionally, the width-height ratios of the honeycomb cells between the layers of the honeycomb core layer are different and change in a gradient from front to back.

[0026] Compared with the traditional single wall plate, the main structure of the explosion-proof wall provided in the embodiments of the present application includes the first wall plate and the second wall plate perpendicular to each other, and the whole is in an L shape. It has been verified that, compared with the single wall plate, the L-shaped explosion-proof wall has better impact resistance and thus better protection performance. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is an embodiment of the arrow-shaped honeycomb cell structure schematic diagram

[0028] Figure 2Figure 1 is a schematic diagram of a hexagonal honeycomb cell structure in an embodiment.

[0029] Figure 3 Figure 2 is a schematic diagram of an arc-shaped honeycomb cell structure in an embodiment.

[0030] Figure 4 Figure 3 is a schematic diagram of a honeycomb core structure in an embodiment.

[0031] Figure 5 Figure 4 is a schematic diagram of a partial blast wall structure in an embodiment, with the honeycomb cell being an arc-shaped cell.

[0032] Figure 6 Figure 5 is a schematic diagram of a partial blast wall structure in an embodiment, with the honeycomb cell being an arrow-shaped cell.

[0033] Figure 7 Figure 6 is a schematic diagram of a partial blast wall structure in an embodiment, with the honeycomb cell being a hexagonal cell.

[0034] Figure 8 Figure 7 is a schematic diagram of an arc-shaped honeycomb core structure with different concave angles in an embodiment. θ

[0035] Figure 9 Figure 8 is a schematic diagram of an arc-shaped honeycomb core blast wall structure with different width-height ratios in an embodiment. l / h

[0036] Figure 10 Figure 9 is a schematic diagram of an L-shaped blast wall layout on a platform (top view) in an embodiment.

[0037] Figure 11 Figure 10 is a schematic diagram of a right-angled corner L-shaped blast wall structure in an embodiment.

[0038] Figure 12 Figure 11 is a schematic diagram of an arc-angled corner L-shaped blast wall structure in an embodiment.

[0039] Figure 13 Figure 12 is a schematic diagram of a right-angled corner L-shaped blast wall verification model structure in an embodiment.

[0040] Figure 14 Figure 13 is a schematic diagram of an arc-angled corner L-shaped blast wall verification model structure in an embodiment.

[0041] Figure 15 Figure 14 is a schematic diagram of the size of the air domain and the position of the blast wall in a verification model.

[0042] Figure 16 Figure 15 is an explosion finite element model, in which a is a two-point explosion finite element model; b is a single-point explosion finite element model equivalent to the two-point explosion.

[0043] ​​Figure 17 For the explosive finite element model, where c is a single-point explosive model, d is a two-point explosive model, and c is a three-point explosive model.

[0044] Figure 18 For the anti-explosive performance column chart of configurations I-III in the embodiments of the present application.

[0045] Figure 19 For the concave arc-shaped honeycomb sandwich blast wall in an embodiment δ max -θ Curve.

[0046] Figure 20 For the concave arc-shaped honeycomb sandwich blast wall in an embodiment SEA-θ Curve.

[0047] Figure 21 For the concave arc-shaped honeycomb sandwich blast wall in an embodiment P-θ Curve.

[0048] Figure 22 For the concave arc-shaped honeycomb sandwich blast wall in an embodiment δ max - width-height ratio curve.

[0049] Figure 23 For the concave arc-shaped honeycomb sandwich blast wall in an embodiment SEA - width-height ratio curve.

[0050] Figure 24 For the concave arc-shaped honeycomb sandwich blast wall in an embodiment P - width-height ratio curve.

[0051] Figure 25 For the maximum deformation-explosion distance curve of the concave arc-shaped honeycomb sandwich blast wall in an embodiment

[0052] Figure 26 For the maximum deformation column chart of different angles in an embodiment

[0053] In the figure: h is the height of the honeycomb cell;

[0054] l is the width of the honeycomb cell;

[0055] a is the width of the connecting piece between the honeycomb cells;

[0056] t is the wall thickness of the honeycomb cell;

[0057] θ 1 and θ 2The angle between different cell walls of the honeycomb cell;

[0058] θ The angle of the concave honeycomb cell, wherein the concave arc is θ The angle is defined as the angle between the tangent of the arc at the end point and the horizontal direction.

[0059] H The height (vertical direction) of the honeycomb core layer;

[0060] T The thickness of the honeycomb core layer;

[0061] 1. Front panel, 2. Honeycomb core layer (also known as honeycomb sandwich), 3. Rear panel, 4. Living area, 5. L-shaped explosion-proof wall, 6. Equipment area, 7. Explosion point. Embodiment

[0062] Referring to the drawings accompanying the specification Figure 10 , the living area 4 is the protected object, and the equipment area 6 is the object that may cause an explosion, so the traditional explosion-proof wall is arranged between the living area 4 and the equipment area 6, and as a whole, it is a vertical single-sided wall. The traditional explosion-proof wall is mainly used to protect against the impact from the front of the equipment area, however, although explosions occur in the equipment area 6 in most cases, they may also occur elsewhere due to the spread of, for example, oil and gas, and explosions may occur in multiple places, and a single-sided wall is difficult to provide good protection in the face of complex accidents.

[0063] In addition, the explosion-proof wall mainly relies on the elastic or plastic deformation of the wall to resist the impact generated by the explosion, and the deformation capacity provided by the single-sided wall is relatively limited, especially on both sides.

[0064] Further, the structure on the offshore platform is complex, pipelines are densely arranged, and the living area is located on the platform, and explosions may occur around it, so the traditional single-sided explosion-proof wall obviously cannot meet this requirement, so it is particularly important to protect the entire living area from explosions. Combining single-sided explosion-proof walls to protect against disasters such as explosions can solve this problem, but the combined explosion-proof wall faces the problem of connection at the corner position. The present application designs two different L-shaped honeycomb explosion-proof walls for explosion protection at the corner position, as shown in Figures 12-14 , and in order to better detect the explosion resistance of this type of explosion-proof wall, numerical simulation of the two types of honeycomb explosion-proof walls under multiple-point explosion is carried out in detail.

[0065] Among them, Figures 12-14 shows two L-shaped honeycomb explosion-proof walls, and the difference between the two L-shaped honeycomb explosion-proof walls is that one corner is a right angle and the other corner is an arc. Figure 11 and Figure 13The structure of the right-angle corner L-shaped honeycomb blast wall is shown, and one geometric dimension is illustrated. Figure 12 and Figure 14 The structure of the circular-arc corner L-shaped honeycomb blast wall is shown, and one geometric dimension is illustrated.

[0066] As mentioned above, the L-shaped honeycomb blast wall is composed of a central honeycomb core layer (honeycomb sandwich) 2 and two steel plate panels on the sides. Except for the difference in the corner, the parameters of the honeycomb core layer of the two L-shaped honeycomb blast walls are consistent, i.e. the honeycomb core layer is arranged by inner concave arc-shaped honeycomb cells in a 3x6 layout, and the inner concave arc-shaped honeycomb cells are in accordance with the optimized result size mentioned above, i.e. the inner concave angle is 45°, and the width-height ratio is 1.1. The geometric size of the cell is calculated as follows: width = 0.0363 m, height = 0.033 m. The thickness of the honeycomb cell is t = 0.001 m. l h

[0067] Specifically, the basic structure of the blast wall is shown on the wall body, which includes a front panel 1 facing outward relative to the living area 4 or the protected object and a rear panel 3 facing the protected object such as the living area 4. The front panel 1 and the rear panel 3 are arranged in parallel and have a certain distance, forming a space, and the honeycomb core layer 2 is arranged in the space. In turn, the front and rear are determined, and in this reference system, the front also represents the outside, and the rear also represents the inside.

[0068] In addition, for the blast wall, in the traditional concept, the front-rear direction is also the thickness direction of the blast wall, and the extension direction of the blast wall is the upward-downward extension and the left-right extension, wherein the upward-downward extension direction is the height direction of the blast wall, and the left-right extension direction is the height direction of the blast wall. In the embodiment of the present application, unless otherwise specified, the reference system is based on the aforementioned front-rear-left-right-up-down.

[0069] The principles of the present application will be described in detail below in combination with the blast-proof mechanism of the blast wall and the drawings in the specification, and the advantages and specific effects of the present application will be described in the form of specific embodiments.

[0070] Unlike traditional blast walls, Figure 10 The blast wall shown is an L-shaped blast wall 5, which includes two wall bodies, referred to as a first wall body and a second wall body, one of which is directly facing the equipment area 6, and the other is located on the lower side of the living area 4 in the figure. Both wall bodies are vertically arranged and adjacent to each other in the figure, and are fixedly connected to form an integral structure.

[0071] In addition, Figure 10 As can be seen in the figure, the living area 4 is slightly offset to one side on the platform, and the second wall body in the L-shaped blast wall 5 is located on the opposite side of the offset side.

[0072] ​​It should be known that the L-shaped explosion-proof wall 5 shows a configuration mode, and it can be seen from the embodiments of the present application that, by means of the basic principle of the L-shaped explosion-proof wall 5, the explosion-proof wall can have two second wall bodies, and one is arranged at each of the left and right ends of the first wall body.

[0073] The following continues to analyze the explosion resistance of the explosion-proof wall by using part of the model (such as Figure 13 and Figure 14 ). The ALE method is used to simulate the explosion resistance of the L-shaped honeycomb explosion-proof wall under multi-point explosive explosion. In the ALE method, an Euler domain needs to be established, and the structure and explosive to be analyzed are included in the Euler domain. The air domain is defined as the Euler domain in this chapter, and the size and position of the air domain are shown in Figure 15 . The center of the square explosive is defined as the ignition point by using the keyword INITIAL_DETONATION, and the equivalent is determined by its volume. In order to eliminate the influence of the air domain boundary reflection on the explosion response of the explosion-proof wall structure, the boundary of the air domain is set as a non-reflective boundary to avoid reflection. Considering the accuracy and calculation efficiency of numerical simulation, the grid element size of the honeycomb core layer and the panel of the explosion-proof wall structure is 0.01 m through grid sensitivity analysis. In order to more accurately calculate the fluid-structure coupling result, the size of the air domain grid is also defined as 0.01 m.

[0074] In order to better simulate the explosion resistance of the L-shaped honeycomb explosion-proof wall under multi-point explosion, different working conditions are set by changing the position and number of explosives in this part, so as to simulate the explosion resistance of the explosion-proof wall under different explosion scenes. In the case of two-point explosion, the influence of explosion spacing on the explosion resistance of the explosion-proof wall is analyzed, and compared with the single-point explosion of the same equivalent. The two explosives of two-point explosion are distributed on both sides of the vertical direction of the explosion-proof wall at 0.25 m, and the explosion spacing is 2 L , and the position is shown in Figure 16 left. While the position of the single-point explosion with the same equivalent as the two-point explosion is shown in Figure 16 right. The working conditions of two-point explosion with different explosion spacing are shown in Table 3.

[0075] Table 3 Different working conditions

[0076]

[0077] The working conditions of multi-point explosion acting on the L-shaped honeycomb explosion-proof wall can be divided into two different L-shaped honeycomb explosion-proof wall single-point, two-point and three-point explosion. Among them, the position and layout of the explosives of single-point explosion, two-point explosion and three-point explosion and the L-shaped honeycomb explosion-proof wall are as shown in Figure 17 . The three-point explosion working condition is the combination of single-point working condition and two-point working condition. The working conditions of multi-point explosion of different structures are shown in Table 4.

[0078] Table 4 Different working conditions

[0079]

[0080] The following examines the unilateral multi-point explosion simulation results:

[0081] (1) The transmission law of shock wave in the honeycomb blast wall:

[0082] In order to study the damage deformation of the blast wall under two-point explosion at different explosion intervals, the interval between two-point explosion is changed for numerical simulation, and compared with the equivalent single-point explosion. In an experiment, the interval between two-point explosion is 0.18 m, and the transmission cloud of the shock wave of two-point explosion is examined. From the dynamic changes of the transmission cloud, it can be seen that after the initiation of two-point explosion with equivalent amount, the shape of the pressure wave is similar to that of the explosive at first, and the position with the maximum pressure is inside the explosive. With the increase of time, the two shock waves become circular and meet on the center plane of symmetry, and the collision and superposition of the two shock waves occur on the center plane of symmetry, forming a new wave front which continues to propagate to both sides of the center. Due to the superposition of the shock wave, the pressure at the position of the center plane is obviously higher than that at other positions. The original two wave fronts will reach the structure in advance, causing deformation of the structure. After being blocked by the blast wall, the shock wave will propagate and diffuse along the blast wall, and finally act on the entire blast wall on one side.

[0083] Further examine the pressure propagation cloud of the shock wave acting on the blast wall. When the shock wave propagates to the blast wall, the pressure on the blast wall will correspond to the two-point explosive, and because of the action of the new wave front, the pressure at the center position is higher than that at the two sides. With the propagation of the pressure, two negative pressure positions will be formed on the blast wall, and finally the two negative pressures will merge into one negative pressure at the center position. The position with the highest pressure is at the boundary of the blast wall.

[0084] The following examines the deformation of the blast wall under different explosion intervals:

[0085] The deformation characteristics of the unilateral blast wall caused by two-point explosion with different explosion intervals have the same law. The pressure propagation situation is described in the form of simulated explosion cloud when the explosion interval is 0.18 m. Correspondingly, the deformation of the blast wall is also based on the deformation of the blast wall, and the cloud is simulated. From the blast wall deformation cloud, it can be seen that the shock wave generated by two-point explosion will produce two obvious deformation positions on the blast wall, and with the spread of the shock wave on the blast wall, the deformation at the center position will become larger and larger, finally forming a single-point concave with the center position as the maximum deformation.

[0086] The deformation figures of the explosion-proof wall under different explosion intervals are further simulated. It can be seen from the simulation results that the deformation modes of the explosion-proof wall under different explosion intervals are basically consistent, and finally a single-point depression is generated at the center position. The deformation range is also continuously increasing with the increase of the interval. The results of two-point explosion compared with single-point explosion can find that the smaller the explosion interval, the more consistent the deformation range with single-point explosion. According to Table 5, when the explosion interval is greater than or equal to 0.18 m, the maximum deformation δ max of the explosion-proof wall is less than that of single-point explosion. When the explosion interval is less than 0.18 m, the maximum deformation δ max of the explosion-proof wall is greater than that of single-point explosion, and the smaller the interval, the greater the maximum deformation. This shows that the deformation caused by multi-point explosion is greater than that of single-point explosion with the same equivalent when the interval is less than a certain value.

[0087] Table 5 Maximum deformation of different explosion intervals

[0088]

[0089] According to the maximum deformation of different explosion intervals, the maximum deformation δ max and explosion interval curve is drawn, as shown in Figure 25 . It can be found that with the increase of the explosion interval, the maximum deformation δ max of the explosion-proof wall is continuously decreasing, and the relationship between the maximum deformation and the explosion interval can be approximately linear. It can be seen that the greater the interval of multi-point explosion with the same equivalent, the smaller the damage to the structure.

[0090] In addition, through the simulation of the deformation cloud of the explosion-proof wall and the simulation of the interface deformation figure, it can be found that the deformation of the honeycomb structure caused by the explosion shock wave is mainly concentrated in the explosion face of the honeycomb sandwich. The deformation degree of the honeycomb cell near the explosion face is the largest, while the deformation of the back plate and the honeycomb cell near it is very small, which shows that this type of explosion-proof honeycomb sandwich wall can effectively protect the structure behind the explosion-proof wall.

[0091] The anti-explosion performance of the 5.2 L-type honeycomb explosion-proof wall under multi-point explosion is verified as follows:

[0092] In order to test the anti-explosion ability of the L-type explosion-proof wall with two different angles under different explosion loads, three different explosion loads, i.e. single-point explosion, two-point explosion and three-point explosion, are used to carry out explosion loading on the L-type explosion-proof wall.

[0093] The shock wave cloud maps of three different explosion loads are simulated in the same way as described above. Through the intuitive simulation of the shock wave cloud map, it can be seen that the shock wave of single-point explosion will be dispersed to both sides under the action of the corner of the L-shaped honeycomb blast wall. Two-point explosion is distributed on both sides of the L-shaped honeycomb blast wall, and the two shock waves will collide with the blast wall first, and then meet at the corner position to form a new wave front, and then collide with the corner. The shock waves formed by three-point explosion will first meet to form a new wave front due to the close distance. Due to the special layout of three-point explosion, the two new wave fronts are perpendicular to each other, and after meeting again, a wave front is formed to act on the corner of the blast wall.

[0094] In order to better compare the differences of the two blast walls at the corner, the propagation law of the pressure on the blast wall of single-point explosion is compared, and the deformation of the two blast walls at the corner is simulated in the same way as described above. According to the simulation, it can be seen that the L-shaped blast wall with a right-angle corner has a highest pressure value near the corner after being contacted by the shock wave, and the pressure is transmitted to both sides, and the pressure range is only half of the single side, and the pressure cannot be well dispersed. The L-shaped blast wall with a circular arc corner can disperse the pressure to a larger range when it is first contacted by the shock wave, and it can better cover most of the single side area during subsequent pressure transmission, and better disperse the pressure to the entire blast wall. By comparing the maximum pressure of the two blast walls, it can be found that the pressure of the circular arc corner is less than that of the right-angle corner, which further reflects the stronger pressure dispersion capability of the circular arc corner.

[0095] Further, the maximum deformation cloud maps of the L-shaped honeycomb blast walls with two different corners under different explosion loads are simulated. It can be found from the analysis of the maximum deformation cloud map that the damage to the blast wall caused by single-point explosion at the corner position is obviously less than that caused by explosion at other positions. The corner can disperse the explosion shock wave, so that the shock wave does not directly impact the blast wall vertically, reducing the damage to the blast wall.

[0096] From the simulated single-point explosion cloud map, it can be found that the maximum deformation caused by single-point explosion on the right-angle corner blast wall is not at the corner position and has a certain distance from the corner. The maximum deformation caused by single-point explosion on the circular arc corner blast wall is at the corner, and due to the support in two directions at the corner position, the maximum deformation is less than that of the right-angle corner blast wall. In an embodiment, it can be obtained from the simulated maximum deformation cloud map that the maximum deformations of the right-angle corner blast wall under single-point explosion, two-point explosion and three-point explosion are 0.576 mm, 16.88 mm and 17.71 mm respectively (as comparative data under the same equivalent), and the maximum deformations of the circular arc corner are 0.2336 mm, 0.8693 mm and 2.397 mm respectively. According to the maximum deformation, a column chart is drawn as shown in Figure 23 ComparingFigure 23 The maximum deformation in the circular corner is obviously smaller than that in the right-angled corner. Since the circular corner connects the vertical explosion-proof walls continuously and the honeycomb core is also connected through the circular corner, the impact resistance of the honeycomb core is ensured at the corner position. However, the right-angled corner only connects the surface panels, and the honeycomb core is obviously disconnected at the corner position, and thus cannot play the impact resistance of the honeycomb core.

[0097] Therefore, in some embodiments, the front panel 1 and the rear panel 3 of the right-angled corner can be a steel plate bent, can be a split panel connected by welding, or can adopt a detachable structure, for example, through an angle bar, the angle bar is provided with bolt holes, the edges of the front panel and the rear panel are provided with flanges, the flanges are provided with corresponding bolt holes, and the two front panels 1 are connected by bolts.

[0098] Generally, riveting is a kind of non-detachable connection, and the fatigue resistance is much higher than that of bolts. In addition, riveting belongs to quasi-detachable connection compared with welding. However, it should be known that, in most cases, the explosion-proof wall is a long-term fixed object, and thus riveting is better than bolt connection.

[0099] The two wall panels of the L-shaped explosion-proof wall are defined as a first wall panel and a second wall panel, the connecting sides of the two wall panels are configured as 45-degree bevels, the bevels are butted to form a 90-degree corner, and then the front and rear panels are welded or connected in other ways to be integrated.

[0100] In some embodiments, after the first wall panel is fixed, the second wall panel is abutted against the rear panel 3 of the first wall panel, and the front and rear panels of the second wall panel are fixedly connected with the rear panel 3 of the first wall panel.

[0101] In the embodiments of the present application, the plate-to-plate connection can be achieved by using an angle bar, in which case the flange is not required, or the flange can be provided. If the corresponding edges of the plates are provided with flanges, the plate-to-plate connection does not need to use an angle bar as an accessory.

[0102] Regarding the honeycomb core 2, the core can be continuous on the two wall bodies, or can be split. In the preferred embodiments, the connecting part between the two wall bodies needs to be reinforced if the core is split.

[0103] The honeycomb core 2 is one of the main components of the explosion-proof wall, and the honeycomb cell is an array unit of the honeycomb core 2. The geometric characteristics of the honeycomb cell are described below, and different reference systems are used for the honeycomb cell for the convenience of description. For reference, see the geometric characteristics of the honeycomb cell in the drawings. Figures 1-3 The height of the honeycomb cell is shown in FIG. 1. h The width of the honeycomb cell is shown in FIG. 1. l The width of the honeycomb cell is shown in FIG. 1. aThe width of the connecting piece between the honeycomb cells; t The wall thickness of the honeycomb cell; θ 1 And θ 2 The angle between different walls of the honeycomb cell; θ The angle of the concave honeycomb cell, wherein the concave arc shape θ The angle is defined as the included angle between the tangent of the circular arc at the end point and the horizontal direction.

[0104] Wherein, Figure 1 The example honeycomb cell is an arrow-shaped honeycomb cell, and the upper and lower ends in the figure correspond to the thickness direction of the honeycomb core layer 2, i.e. the front and back directions, which correspond to the height h of the honeycomb cell; Figure 2 And Figure 3 The example honeycomb cell in the middle is the same.

[0105] For example Figure 2 The concave hexagonal honeycomb cell in the middle is based on a square continuous array in a plane perpendicular to the paper plane to form a layer of honeycomb cells, and one honeycomb core layer 2 is often composed of multiple layers of honeycomb cells, and the number of layers is generally 4-7 layers, and 5 layers are the most.

[0106] Figure 4 A structural schematic diagram of a honeycomb core layer 2 is shown, and it can be seen from the figure that the honeycomb cell is a concave arc-shaped honeycomb cell, and the whole is 5 layers. In the figure, H represents the height of the honeycomb core layer 2, i.e. the vertical dimension; T represents the thickness of the honeycomb core layer, i.e. the dimension in the front and back directions.

[0107] To ensure the quality consistency of different honeycomb core layers, the relative density is used to design the honeycomb core layer to obtain the size and arrangement number of the honeycomb cell. Let N1 And N2 Respectively represent the number of cells in the height direction and the thickness direction of the honeycomb core layer. Therefore, the relative density of the arrow-shaped honeycomb core layer is ΔρA The relative density of the concave hexagonal honeycomb core layer is ΔρCh The relative density of the concave arc-shaped honeycomb core layer is ΔρCa For:

[0108]

[0109] Here, in order to compare the blast resistance of the three kinds of honeycomb structures, the relative densities of the three kinds of honeycomb core layers ΔρA , ∆ ρCh , ΔρCa Should be equal.

[0110] Accordingly, the number of honeycomb cells and the size of each honeycomb cell can be determined. In the case of maintaining the same relative density, the number of cells and the size of the three kinds of honeycomb core layers are calculated as shown in Table 1.

[0111] Table 1. Number and size of cell cells

[0112]

[0113] The following explanation uses one wall panel of the L-shaped explosion-proof wall 5 as an example, which is called a single-sided honeycomb core layer explosion-proof wall. The combination of two or three sides constitutes the L-shaped explosion-proof wall 5.

[0114] In one embodiment, a single-sided honeycomb core layer explosion-proof wall consists of a front panel 1, a rear panel 3, and a honeycomb core layer 2 with five honeycomb cells. Both panels are 2 mm thick, and the honeycomb core layer 2 is 200 mm thick, resulting in a total thickness of 204 mm for the honeycomb core layer explosion-proof wall. Since a full-size L-shaped explosion-proof wall 5 would be too complex and significantly reduce computational efficiency, a simplified method can be adopted to analyze the impact of different cell configurations on the explosion-proof performance of the wall. This involves establishing only a local model with dimensions of 1 m × 0.8 m × 0.204 m. Figure 5 As shown.

[0115] Given that the cell configurations of each cell are roughly the same, differing only in cell shape, therefore, Figures 5-7 Three different single-sided explosion-proof wall models with cellular cells as the basic unit are shown.

[0116] During an explosion, the massive shockwave typically causes plastic deformation or even fracture of materials. Therefore, selecting appropriate materials is crucial for structural analysis. In one embodiment of this invention, 316 stainless steel is selected as the panel material, and all three honeycomb core layers are made of A5052 aluminum alloy.

[0117] In embodiments of the present invention, the maximum deflection ( δ max ) and specific energy absorption ( SEA These two indicators are used to study the explosion-proof performance of honeycomb sandwich explosion-proof walls.

[0118] Maximum deflection (δmax) is a commonly used indicator for evaluating structural deformation under explosive loading. Honeycomb sandwich structures with strong blast resistance typically exhibit smaller deflections. δ max Specific energy absorption ( SEA The energy absorbed per unit mass of the honeycomb core structure can be defined as:

[0119]

[0120] In the formula, σ Strain during structural deformation; ε The stress during structural deformation; M The quality of the honeycomb core layer;TEA Plastic energy absorption of the honeycomb core. SEA The higher the value, the better the blast resistance of the sandwich structure.

[0121] From the above two indicators δ ma x And SEA It can be seen from the definition that both indicators should be considered in the actual honeycomb sandwich blast design. Here, in order to comprehensively evaluate the blast resistance of the sandwich structure, the ratio of SEA and δ max is defined as P :

[0122]

[0123] P The specific energy absorption represents the specific energy absorption of the structure unit impact depth. It can be seen that P The higher the value, the better the blast resistance of the structure.

[0124] The influence of different honeycomb cell configurations is analyzed as follows:

[0125] The maximum deflection δ max is defined as the deflection of the center point of the front panel, that is, the point with the maximum deflection in the entire honeycomb sandwich blast wall structure. According to the simulation results, the δ max values of the blast wall of three cell configurations are calculated and listed in Table 2. By comparing δ max It can be seen that the concave arc honeycomb sandwich blast wall (configuration III) has the smallest deformation of 0.0575835 m, while the concave hexagonal honeycomb sandwich blast wall (configuration II) has the largest deformation of 0.1346310 m. Therefore, the concave arc honeycomb sandwich blast wall (configuration III) has the best blast deformation resistance performance.

[0126] Table 2 Blast resistance indicators of three configurations

[0127]

[0128] On the other hand, the blast resistance of the blast wall can be evaluated from the SEA of the honeycomb sandwich structure. According to the simulation results, the SEA values of the three configurations are calculated and listed in Table 2. By comparing the SEA, it can be seen that the SEA of the concave arc honeycomb sandwich blast wall (configuration III) is the smallest, which is 1138.625587 J•kg -1 , while the SEAMaximum, 1516.538976 J•kg -1 It can be seen that the inner concave hexagonal honeycomb (configuration II) has the best energy absorption capacity during the blast resistance process, which is consistent with the maximum deformation δ max The evaluation of the indicators seems to be inconsistent.

[0129] As described above, P This comprehensive indicator is a better choice for evaluating the blast resistance performance of the honeycomb sandwich blast wall. Therefore, the values of P are calculated and listed in Table 2. By comparing the three indicators in Figure 18 , it can be seen that the inner concave arc-shaped honeycomb sandwich blast wall (configuration III) P has the maximum value of 19773.46961 J•(kg•m) -1 , which proves that configuration III has the best protection effect on the equipment under the blast load among the three honeycomb structures.

[0130] The preferred scheme of the blast resistance performance of the inner concave arc-shaped blast wall is described as follows:

[0131] By changing the geometric parameters of the honeycomb cells, the mechanical properties of the honeycomb sandwich can be changed. From the above analysis results and evaluation results, the inner concave arc-shaped honeycomb can be selected as the basic configuration form of the honeycomb sandwich blast wall. However, different geometric parameters of the honeycomb cells, such as the inner concave angle θ and the width-height ratio l / h , also have important effects on the blast resistance performance under the blast load.

[0132] Based on this, after selecting the inner concave arc-shaped honeycomb as the basic configuration, the next step will be to optimize the different geometric parameters of the inner concave arc-shaped cells to obtain the best blast resistance performance.

[0133] Referring to Figure 2 , first consider the preferred example of the inner concave angle θ :

[0134] In order to optimize the inner concave angle θ of the inner concave arc-shaped honeycomb, 7 inner concave angles (θ) of 15°, 25°, 35°, 45°, 55°, 65° and 75° are taken at intervals of 10° between 0° and 90°. The inner concave arc-shaped honeycomb sandwich blast wall is designed with the same parameters unchanged when the inner concave angle is changed. Figure 8 is the finite element model of the established inner concave arc-shaped honeycomb sandwich blast wall with different inner concave angles. Based on the same simulation method, numerical analysis is performed on these models.

[0135] Figure 19 is δ max -θThe curve shows the maximum deflection of the honeycomb sandwich explosion-proof wall. δ max The concave angle of the concave arc honeycomb θ The concave angle gradually decreases as it increases. The results show that the concave angle... θ The larger the value, the better the effect of reducing the maximum deformation. Figure 20 for SEA-θ The curve shows that the SEA (Self-Absorption Aspect) of the honeycomb sandwich explosion-proof wall gradually decreases as θ increases. The results indicate that a smaller concave angle leads to better energy absorption.

[0136] In addition, we have drawn up a composite index ( P - Concave angle ( θ ) curve, such as Figure 21 As shown in the figure. The curve shows that, with... θ The increase of the ratio P First it increases, then it decreases. When θ At 45°, the ratio P Reached its maximum value. Figure 18 It can be seen that when θ As the angle increases, the concave arc becomes increasingly straight. When the concave angle is large enough, the concave arc structure itself will lose its negative Poisson's ratio characteristic and energy absorption advantage, thus... P The value decreased.

[0137] Next, we consider the aspect ratio ( l / h Preferred example:

[0138] Figure 9 The aspect ratios are 1.0, 1.1, 1.2, 1.3, 1.4, and 1.5. l / h A concave arc-shaped honeycomb sandwich explosion-proof wall model was constructed. With the aspect ratio changed, other geometric parameters, boundary conditions, and explosion loads remained consistent with the previous section. Under these conditions, the effect of aspect ratio on blast resistance was investigated.

[0139] Figure 22 Maximum deflection ( δ max – Aspect Ratio l / h The curve shows the maximum deflection of the honeycomb sandwich explosion-proof wall. δ max With aspect ratio l / h The aspect ratio gradually increases with the increase of [the property / value]. The results show that the aspect ratio [is related to the property / value]. l / h The smaller the value, the better the performance in reducing the maximum deformation. Figure 23 for SEA-θ The curve shows that the honeycomb sandwich explosion-proof wall... SEA The aspect ratio gradually increases with increasing aspect ratio. The results show that the aspect ratio... l / hThe larger the diameter, the better the blast resistance and the more energy it can absorb from the blast shock wave.

[0140] In addition, it was drawn P – Aspect Ratio l / h Curves, such as Figure 24 As shown in the figure, it can be seen that with the aspect ratio... l / h The increase in the ratio P First increase, then decrease. When the aspect ratio... l / h When =1.1, P The maximum value is reached. At this point, the explosion-proof performance of the concave-corner honeycomb sandwich explosion-proof wall is optimal.

[0141] Based on the above, it can be concluded that the concave arc-shaped honeycomb cell is the optimal configuration, and the optimal geometric dimensions are as follows: concave angle ( θ Take 45°, aspect ratio ( l / h Take 1.1. However, it should be known that these two geometric parameters are the optimal parameters. Within the preferred and usable range, those skilled in the art can still choose different parameter values ​​according to their own needs. However, it should be known that the optimal is often not replaceable.

[0142] Furthermore, as mentioned above, the explosion-proof performance of the concave arc-shaped honeycomb sandwich explosion-proof wall is superior to that of the arrow-shaped honeycomb sandwich explosion-proof wall and the concave hexagonal honeycomb sandwich explosion-proof wall. However, it should be understood that, as usable means, the arrow-shaped honeycomb sandwich explosion-proof wall and the concave hexagonal honeycomb sandwich explosion-proof wall still have their applicable scope.

[0143] The maximum deflection of the concave arc-shaped honeycomb sandwich explosion-proof wall, which is the optimal choice, decreases as the concave angle increases; however, it leads to more energy absorption. Overall, a concave angle of 45° yields the best explosion-proof performance.

[0144] As a design reference, for example, the shock wave generated by two-point explosions will create a negative pressure area on the structure at the position of the central symmetrical plane of its cellular explosion-proof wall, and the highest pressure on the structure is distributed around the boundary.

Claims

1. An offshore platform cellular core blast wall, characterized by, The utility model relates to a wallboard for protecting objects, comprising: a first wallboard vertically shielding a first side of the protected object; a second wallboard vertically shielding a second side of the protected object, which is adjacent to the first side; accordingly, the first wallboard and the second wallboard are fixedly connected at the adjacent ends to form a whole; the first wallboard and the second wallboard each comprise a front panel on the outer side relative to the protected object and a rear panel on the inner side, and a honeycomb core layer between the front panel and the rear panel; the first wallboard and the second wallboard are connected at right angles or through a rounded corner transition; the width-height ratio of the honeycomb cells in each layer of the honeycomb core layer is different and changes in a gradient from the front to the rear.

2. The offshore platform cellular core blast wall of claim 1, wherein, If the first wallboard and the second wallboard are connected at right angles, the first wallboard and the second wallboard have: a first connection mode, in which one end of the second wallboard abuts against the corresponding end side of the first wallboard, and the front and rear panels of the second wallboard are welded or connected through an angle bar or a rivet with a flange or a bolt with the rear panel of the first wallboard; a second connection mode, in which the second wallboard and the front panel of the first wallboard are integrally bent or fixedly connected, and the rear panels are integrally bent or fixedly connected; the fixedly connected mode is welding or connecting through an angle bar or a rivet with a flange or a bolt; If the first wallboard and the second wallboard are connected through a rounded corner transition, at least the corresponding two front panels are connected through a rounded corner transition, then the first wallboard and the second wallboard have: a third connection mode, in which the corresponding two front panels are integrally bent to form a front rounded corner transition part; if the rear panels are also connected through a rounded corner transition, the corresponding two rear panels are integrally bent to form a rear rounded corner transition part; a fourth connection mode, in which the corresponding two front panels are fixedly connected through a front rounded corner transition piece; if the rear panels are also connected through a rounded corner transition, the corresponding two rear panels are fixedly connected through a rear rounded corner transition piece.

3. The offshore platform cellular core blast wall of claim 2, wherein, The radius of the front rounded corner transition part or the front rounded corner transition piece is 0.9-1.5 times the thickness of the honeycomb core layer.

4. The offshore platform cellular core blast wall of claim 2, wherein, In the second to fourth connection modes, the two honeycomb core layers are continuous honeycomb core layers.

5. The offshore platform cellular core blast wall of claim 1, wherein, The honeycomb core layer is an inner concave arc-shaped honeycomb core layer.

6. The offshore platform cellular core bulkhead of claim 1 or 5, wherein, The number of layers of the honeycomb core layer is 4-7, and the thickness is 0.16-0.28 m.

7. The offshore platform cellular core bulkhead of claim 5, wherein, The honeycomb cells in the inner concave arc-shaped honeycomb core layer are inner concave honeycomb cells, the inner concave angle of the inner concave honeycomb cells is 40-50 degrees, and the width-height ratio is 0.9-1.

3.

8. The offshore platform cellular core blast wall of claim 7, wherein, The inner concave angle is 45 degrees, and the width-height ratio is 1.1.

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