A shipboard bulkhead deformation protection device and method of designing the same

Abstract

The application discloses a ship cabin wall deformation protection device and a design method thereof. The design method comprises the following steps: constructing a simulation model of the protection device, wherein the protection device comprises two same fixed bases which are fixed on the top deck and the bottom deck of the cabin wall and comprise symmetrically connected internal arc-shaped bases and external arc-shaped bases, and a middle arc-shaped plate which is connected with the two fixed bases and is tangent to the cabin wall at the arc-shaped section of the middle arc-shaped plate, and the thickness of the middle arc-shaped plate at the two ends of the arc-shaped section is smaller than the thickness of the middle arc-shaped plate in the arc-shaped section. The application can obtain the ship cabin wall deformation protection device which has the boundary deformation coordination capability of the cabin wall and can effectively absorb the impact energy generated by the implosion.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of ship bulkhead protection devices, in particular to the technical field of anti-impact and anti-blast ship bulkhead deformation protection devices. BACKGROUND

[0002] With the rapid increase of anti-ship weapon types, the modern ship bulkhead has higher and higher requirements for blast impact protection. At present, the ship bulkhead is mostly protected by blast walls, which mainly select high-strength steel plates with good impact resistance. Although the blast wall can effectively resist the impact caused by the blast, it is difficult to resist the boundary damage caused by the large deformation of the bulkhead when the blast occurs. From the existing cases of bulkhead damage caused by the blast, the damage of the bulkhead indeed mostly occurs at the boundary part of the bulkhead. Therefore, it is particularly necessary to improve the deformation coordination ability of the bulkhead boundary and enhance the boundary protection performance. SUMMARY

[0003] The purpose of the present application is to provide a ship bulkhead deformation protection device with bulkhead boundary deformation coordination ability and effective absorption of impact energy generated by the blast, and a design method thereof. The protection device can strengthen the protection ability of the end part (boundary part) of the bulkhead and protect the surrounding cabin.

[0004] The technical solution of the present application is as follows:

[0005] A design method of a ship bulkhead deformation protection device, comprising:

[0006] A design method of a ship bulkhead deformation protection device, characterized in that it comprises:

[0007] S1, constructing a simulation model of a ship bulkhead deformation protection device;

[0008] S2, obtaining optimal design parameters by simulating the deformation performance of the simulation model of the ship bulkhead deformation protection device under the action of blast impact load;

[0009] S3, preparing the ship bulkhead deformation protection device according to the obtained optimal design parameters;

[0010] The ship cabin wall deformation protection device comprises two fixed bases which are fixed on the top deck and the bottom deck of the cabin wall of the ship and are identical in structure, and a middle arc-shaped plate connected with the two fixed bases respectively, wherein the middle arc-shaped plate is tangent to the cabin wall at the arc-shaped section thereof; each of the two fixed bases comprises an inner arc-shaped base and an outer arc-shaped base which are symmetrically connected, and the connection position of the inner arc-shaped base and the outer arc-shaped base is the connection position of the middle arc-shaped plate and the fixed base; the inner arc-shaped base is an arc-shaped plate tangent to the cabin wall at the arc-shaped section of the inner arc-shaped base; the outer arc-shaped base is an arc-shaped plate which is mirror-symmetric to the inner arc-shaped base; and the thickness of the middle arc-shaped plate at the two ends of the arc-shaped section thereof is smaller than the thickness of the middle arc-shaped plate in the arc-shaped section thereof.

[0011] According to some preferred embodiments of the present application, the middle arc-shaped plate, the inner arc-shaped base and the outer arc-shaped base are made of ship low-carbon steel material.

[0012] According to some preferred embodiments of the present application, the outer surfaces of the middle arc-shaped plate, the inner arc-shaped base and the outer arc-shaped base are coated with an insulating layer.

[0013] According to some preferred embodiments of the present application, the S2 comprises:

[0014] S21, constructing a finite element model of the simulation model;

[0015] S22, setting the material types and parameters of each component in the finite element model and a contact form, wherein the contact form comprises point contact and / or surface contact;

[0016] S23, setting stress and strain conditions met by the material used by the protection device;

[0017] S24, setting finite element parameters in the simulation;

[0018] S25, through simulation, applying a triangular pulse pressure with a uniform distribution and a duration to the set finite element model to simulate the implosion load received by the device;

[0019] S26, solving deformation parameters of the cabin wall under the implosion load by using a finite element software to obtain a cabin wall deformation state, material equivalent plastic strain distribution and stress state results;

[0020] S27, changing the thickness, arc length, arc radius and material selection of the middle arc-shaped plate, the inner arc-shaped base and the outer arc-shaped base in the simulation model under the premise of meeting the strength and deformation requirements of the cabin wall to obtain the parameters corresponding to the minimum weight of the device, which are the optimal protection device design parameters.

[0021] According to some preferred embodiments of the present application, in the S22, the material type and parameters include: the deck is a rigid body, the bulkhead, the middle arc plate, the inner arc base and the outer arc base are all made of low-carbon steel material for ships, with a density ρ=7 850 kg / m 3 , an elastic modulus E=210 GPa, a Poisson's ratio μ=0.3, a quasi-static yield stress σ0=235 MPa, E h =250 MPa, and material constants D and P being D=40.4 / s and P=5, respectively.

[0022] According to some preferred embodiments of the present application, in the S22, the contact form includes: the contact between the bulkhead and the middle arc plate, the contact between the middle arc plate and the inner arc base, and the contact between the middle arc plate and the outer arc base are all surface contact.

[0023] According to some preferred embodiments of the present application, in the S23, the stress and strain conditions include:

[0024] A dynamic yield stress and a static yield stress ratio relationship:

[0025]

[0026] wherein σ d is the dynamic yield stress, σ y is the static yield stress, is the strain rate of the material, and D and P are both material constants.

[0027] A damage opening critical plastic strain ε d A calculation model:

[0028]

[0029] wherein η is a stress triaxiality, D 01 , D 02 , D 03 , D1, D2, D3 and D4 are fracture parameters of the material.

[0030] According to some preferred embodiments of the present application, in the S25, the duration is set to 10 ms.

[0031] According to some preferred embodiments of the present application, the stress state result includes:

[0032] When η≤-1 / 3, the material is only subjected to a compression stress;

[0033] When -1 / 3<η<0, the material is subjected to a combined action of compression and shear stress;

[0034] When η = 0, the material is only subjected to the shearing stress;

[0035] When 0 < η < 1 / 3, the material is subjected to the combined action of the tensile stress and the shearing stress;

[0036] When η >= 1 / 3, the material is only subjected to the tensile stress.

[0037] According to the above design method, the ship cabin wall deformation protection device can be obtained.

[0038] The ship cabin wall deformation protection device can effectively prevent the boundary shearing damage of the cabin wall when the external force in any direction acts on the surface of the cabin wall due to the action of the internal arc base, part of the energy of the cabin wall is transmitted to the middle arc plate, and then a part of the energy is absorbed by the plastic deformation of the middle arc plate, and the remaining part of the energy is transmitted to the external arc base, and the impact energy is dispersed to the deck connected to the external arc base through the external arc base, so that the stress is fully dispersed, and good impact resistance and anti-explosion effect are achieved.

[0039] The ship cabin wall deformation protection device has high strength, excellent end shearing effect, good deformation coordination performance, can effectively resist deformation, has good vibration reduction performance, and can reduce the possibility of crack and fatigue; and the structure is simple, convenient for coating construction and quality inspection.

[0040] In the finite element model of the ship cabin wall deformation protection device established by the application, the cabin wall deformation can be simulated and calculated according to the determined finite element model parameters, then the model size is optimized according to the simulation results, for example, if the simulation results show that the cabin wall and the deck connection part have obvious shearing deformation, even shearing damage, the internal arc base can be replaced with a material with greater stiffness to resist the deformation of the cabin wall or the thickness of the internal arc base can be increased to redesign the size, and then the geometric model of the deformation coordination device is reestablished, and the cabin wall deformation is simulated and calculated again according to the determined finite element model parameters, and the iteration is continuously carried out until the design performance requirements of the ship cabin wall are met, and the method for optimizing the structure according to the finite element simulation results can shorten the development time of the ship cabin wall deformation protection device and greatly improve the development efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 It is a general structure schematic diagram of the ship cabin wall deformation protection device.

[0042] Figure 2 It is a side view structure schematic diagram of the ship cabin wall deformation protection device.

[0043] Figure 3 It is a flow chart of the design method of the ship cabin wall deformation protection device.

[0044] Wherein: 1-deck, 2-vertical bulkhead, 3-central curved plate, 4-internal curved base, 5-external curved base. Detailed Implementation

[0045] The present invention will now be described in detail with reference to embodiments and accompanying drawings. However, it should be understood that the embodiments and drawings are for illustrative purposes only and do not constitute any limitation on the scope of protection of the present invention. All reasonable modifications and combinations included within the inventive spirit of the present invention fall within the scope of protection of the present invention.

[0046] See attached document Figure 3 The implementation process of the design method shown includes:

[0047] S1 constructs a simulation model of a shipboard bulkhead deformation protection device;

[0048] In some specific embodiments, the shipboard bulkhead deformation protection device has the following features: Figures 1-2 The structure shown includes: two identical fixed bases fixed to the top deck 1 and bottom deck of the vertical bulkhead 2; a central arc-shaped plate 3 connected to the two fixed bases respectively; the central arc-shaped plate 3 being tangent to the vertical bulkhead 2 in its arc-shaped section; each of the two fixed bases includes an inner arc-shaped base 4 and an outer arc-shaped base 5 symmetrically connected, the connection point being the connection point between the central arc-shaped plate 3 and the fixed base; wherein, the inner arc-shaped base 4 is an arc-shaped plate tangent to the vertical bulkhead 2 at the end of the arc-shaped section; the outer arc-shaped base 5 is an arc-shaped plate whose arc-shaped section bending direction is opposite to that of the arc-shaped section bending direction of the inner arc-shaped base 4; and the thickness of the central arc-shaped plate 3 at both ends of its arc-shaped section is less than its thickness in the arc-shaped section.

[0049] In the above device, the central arc plate 3 is supported by two inner arc bases 4 and two outer arc bases 5. The central arc plate 3 can absorb and disperse the impact on the vertical bulkhead through deformation. The inner arc bases 4 can change the stress state at the connection between the bulkhead and the deck to achieve good edge shear resistance. The outer arc bases 5 can buffer the deformation impact of the central arc plate and continue to transfer part of the impact to the deck.

[0050] In some specific embodiments, both the inner arc-shaped base 4 and the outer arc-shaped base 5 can be connected to the deck by welding, and the middle arc-shaped plate 3 can be embedded between the inner arc-shaped base 4 and the outer arc-shaped base 5.

[0051] The ship's bulkhead deformation protection device is symmetrical from top to bottom, with a simple structure, high strength, good impact resistance, strong stress dispersion, and high absorption of vibration energy.

[0052] In some preferred embodiments, the outer surfaces of the middle arc plate 3, the inner arc base 4 and the outer arc base 5 are coated with an insulating layer, which is made of ceramic fiber as the main raw material and can be made by wet forming process, and is a high-grade lightweight material with high-temperature resistance, insulation and heat insulation.

[0053] In some preferred embodiments, the middle arc plate 3, the inner arc base 4 and the outer arc base 5 are made of marine low-carbon steel with a yield strength of 235 MPa.

[0054] In the above device, the center, radius, length and thickness of the arc segment of the middle arc plate, the center, radius, length and thickness of the inner arc base, and the center, radius, length and thickness of the outer arc base are obtained according to simulation design.

[0055] S2 obtains the optimal design parameters of the protection device that meet the design performance requirements of the bulkhead by finite element simulation of the deformation process of the simulation model of the ship bulkhead deformation protection device after being subjected to implosion shock.

[0056] In some specific embodiments, the finite element simulation includes:

[0057] S21 constructs a finite element model of the simulation model, such as: the simulation model can be modeled by three-dimensional design software such as Solidworks, Catia, etc., and then further imported into finite element software such as ABAQUS to obtain a finite element model.

[0058] S22 sets the material parameters and contact forms of each structural part in the model.

[0059] As in some specific embodiments, the deck 1 is set as a rigid body, and the vertical bulkhead 2, the middle arc plate 3, the inner arc base 4 and the outer arc base 5 are made of marine low-carbon steel material, and the material parameters are: density ρ = 7 850 kg / m 3 , elastic modulus E = 210 GPa, Poisson's ratio μ = 0.3, quasi-static yield stress σ0= 235 MPa, upper yield strength E h = 250 MPa, and the material constants D and P of low-carbon steel are D = 40.4 / s and P = 5, respectively.

[0060] In some specific embodiments, according to the definition requirements of the contact surface, the contact between the vertical bulkhead 2 and the middle arc plate 3, the middle arc plate 3 and the inner arc base 4, and the middle arc plate 3 and the outer arc base 5 is set as surface contact.

[0061] S23 sets the mechanical conditions that the materials used by the device need to meet.

[0062] The material used in the setting model satisfies the following dynamic yield stress and static yield stress ratio relationship using the Cowper-Symonds model:

[0063]

[0064] Wherein, σ d is the dynamic yield stress, σ y is the static yield stress, is the strain rate of the material, and D and P are both material constants.

[0065] And the material satisfies the following damage opening critical plastic strain ε d Calculation model:

[0066]

[0067] Wherein, η is the stress triaxiality, D 01 , D 02 , D 03 , D1, D2, D3, D4 are the fracture parameters of the material, and are all constants, which are obtained by fitting the material test data.

[0068] S24 sets the finite element parameters in the simulation, such as C3D8R8 nodes controlled by sandglass under the form of mesh division, and the element characteristic edge length is set to 5mm.

[0069] S25 applies a certain duration of uniformly distributed triangular pulse pressure to the finite element model through simulation to simulate the internal explosion load received by the device, and the pressure duration can be set to 10ms.

[0070] S26 obtains the deformation parameters of the bulkhead under the internal explosion load through the finite element software, and obtains the deformation state of the bulkhead, the equivalent plastic strain distribution and the stress state results of the ship bulkhead deformation protection device.

[0071] The solving can be realized by submitting a JOB in the ABAQUS software.

[0072] Wherein, the stress state of each place will change constantly during the deformation process of the bulkhead deformation state. Research shows that the stress characteristics of the material can be directly represented by the stress triaxiality η: when the material is subjected to pure compression, η≤-1 / 3; when the material is subjected to combined compression and shear, -1 / 3<η<0; when the material is subjected to pure shear, η=0; when the material is subjected to combined tension and shear, 0<η<1 / 3; and when the material is subjected to pure tension, η≥1 / 3.

[0073] The equivalent plastic strain distribution and stress state results of the ship bulkhead deformation protection device can be obtained by the post-processing module of the ABAQUS software.

[0074] S27 changing the thickness, arc length, arc radius and material selection of the middle arc plate, inner arc base and outer arc base, taking the strength and deformation requirements of the bulkhead as the design premise, taking the device parameters corresponding to the minimum weight under the design premise as the optimal protection device design parameters, wherein the deformation requirements are, for example, minimizing the maximum plastic deformation, local plastic strain and shear stress of the bulkhead under the premise that the bulkhead does not fail.

[0075] The arc length of the middle arc plate is determined by the distance between the upper deck and the lower deck, the thickness of the middle arc segment and the thickness reduction at the end portion need to meet the requirement of not failing under the load transmitted by the bulkhead, the end portion with reduced thickness should be spliced between the inner arc base and the outer arc base after determining the size, the length of the arc segment at the end portion with reduced thickness should be greater than or equal to the thickness of the inner arc base and the outer arc base, and the arc radius and length of the end portion of the inner arc base are determined according to the thickness of the vertical bulkhead and the arc length and thickness reduction length of the middle arc plate.

[0076] In specific embodiments, the above process can be, for example, the thickness and curvature of the inner and outer arc bases are first determined, a certain gap is reserved therebetween to design the thickness of the end portion reduction area of the middle arc plate, the thickness of the middle region of the middle arc plate is slightly greater than that of the end portion, and then ABAQUS software is used for simulation verification. The gap size between the inner and outer arc bases is continuously adjusted according to the failure state of the bulkhead, so as to adjust the thickness of the middle arc plate. Thus, the thickness of the middle arc plate is minimized under the premise that the end portion of the bulkhead does not fail.

[0077] S3 preparing the ship bulkhead deformation protection device according to the obtained optimal design parameters.

[0078] The above embodiments are only preferred embodiments of the present application, and the protection scope of the present application is not limited to the above embodiments. Any technical solutions falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that improvements and refinements made by ordinary skilled persons in the art without departing from the principles of the present application shall also be considered as falling within the protection scope of the present application.

Claims

1. A method of designing a ship's bulkhead deformation protection device, characterized in that, The application relates to a ship cabin bulkhead deformation protection device. S1: a simulation model of the ship cabin bulkhead deformation protection device is constructed; S2: the optimal design parameters of the ship cabin bulkhead deformation protection device are obtained by simulating the deformation performance of the simulation model of the ship cabin bulkhead deformation protection device under the action of an internal explosion impact load; S3: the ship cabin bulkhead deformation protection device is prepared according to the obtained optimal design parameters; The ship cabin bulkhead deformation protection device comprises two fixed bases which are fixed to the top deck and the bottom deck of the cabin bulkhead of a ship and are identical in structure, and a middle arc-shaped plate connected to the two fixed bases; the middle arc-shaped plate is tangent to the cabin bulkhead at the arc-shaped section; the two fixed bases each comprise a symmetrical internal arc-shaped base and an external arc-shaped base, and the connecting position of the internal arc-shaped base and the external arc-shaped base is the connecting position of the middle arc-shaped plate and the fixed base; the internal arc-shaped base is an arc-shaped plate tangent to the cabin bulkhead at the arc-shaped section of the end; the external arc-shaped base is an arc-shaped plate which is mirror-symmetrical to the internal arc-shaped base; the thickness of the middle arc-shaped plate at both ends of the arc-shaped section is smaller than the thickness of the middle arc-shaped plate in the arc-shaped section. The S2 comprises: S21: a finite element model of the simulation model is constructed; S22: the material types and parameters of each component in the finite element model and the contact form are set, and the contact form comprises point contact and / or surface contact; S23: the stress and strain conditions met by the materials used by the protection device are set; S24: the finite element parameters in the simulation are set; S25: through simulation, a triangular pulse pressure with a certain duration and uniform distribution is applied to the set finite element model to simulate the internal explosion load to which the device is subjected; S26: the deformation parameters of the cabin bulkhead under the action of the internal explosion load are solved by using a finite element software to obtain the deformation state of the cabin bulkhead, the equivalent plastic strain distribution and the stress state results of the materials of the ship cabin bulkhead deformation protection device; S27: the thickness, arc length, arc radius and material selection of the middle arc-shaped plate, the internal arc-shaped base and the external arc-shaped base in the simulation model are changed, and the parameters corresponding to the minimum weight of the device are obtained under the premise of meeting the strength and deformation requirements of the cabin bulkhead, so that the optimal protection device design parameters are obtained.

2. The design method of claim 1, wherein The middle arc-shaped plate, the internal arc-shaped base and the external arc-shaped base are made of ship low-carbon steel materials.

3. The method of designing according to claim 1, wherein, The outer surfaces of the middle arc-shaped plate, the internal arc-shaped base and the external arc-shaped base are coated with an insulating layer.

4. The method of claim 1, wherein In the S22, the material type and parameters include: the deck is a rigid body, the bulkhead, the middle arc-shaped plate, the inner arc-shaped base and the outer arc-shaped base are all ship low-carbon steel materials, the density ρ=7 850 kg / m 3 , the elastic modulus E=210 GPa, the Poisson's ratio μ=0.3, the quasi-static yield stress σ0=235 MPa, the upper yield strength E h =250 MPa, and the material constants D and P are D=40.4 / s and P=5 respectively.

5. The method of claim 1, wherein, In the S22, the contact forms between the cabin bulkhead and the middle arc-shaped plate, the middle arc-shaped plate and the internal arc-shaped base, and the middle arc-shaped plate and the external arc-shaped base are all surface contact.

6. The design method of claim 1, wherein In the S23, the stress and strain conditions comprise: a dynamic yield stress and a static yield stress ratio relationship; where σ d is the dynamic yield stress, σ y is the static yield stress, is the strain rate of the material, and D and P are material constants. Damage initiation critical plastic strain ε d Computational model: wherein η is the stress triaxiality, D 01 , D 02 , D 03 , D1, D2, D3, D4 are the fracture parameters of the material, obtained by fitting the material test data.

7. The method of designing of claim 1, wherein, In the S25, the duration is set to 10 ms.

8. The method of claim 6, wherein, The stress state results comprise: when η<=-1 / 3, the material is only subjected to compression stress; when -1 / 3<eta<0, the material is subjected to the combined action of compression and shear stress; when eta=0, the material is only subjected to shear stress; when 0<eta<1 / 3, the material is subjected to the combined action of tension and shear stress; when eta>=1 / 3, the material is only subjected to tension stress.

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