Method for quickly forecasting resistance of broadside structure in oblique collision scene of wedge-shaped ship bow

Abstract

The invention discloses a method for rapidly forecasting the resistance of a broadside structure in a wedge-shaped ship bow oblique collision scene, and relates to the field of structure safety analysis, comprising the following steps: decoupling a cabin section structure system into a typical resistance unit based on the wedge-shaped ship bow oblique collision scene, and analyzing the deformation stage of the resistance unit in the collision process; establishing a simplified analytical model of the resistance unit in different deformation stages in the collision scene, and deducing an analytical formula of the resistance unit based on an upper limit theorem; dynamically synthesizing the deformation damage resistance of the resistance unit in time and space dimensions through a vector superposition algorithm; based on the interaction among the resistance units, the deformation damage resistance of the resistance units is dynamically accumulated, and damage forecasting of the whole cabin section is achieved. According to the method, an analytic forecasting model of the tearing damage resistance of the boardside structure of the collided ship is established, accurate forecasting of the resistance characteristic and the energy absorption capacity in the whole oblique collision process is achieved, and the collision damage forecasting speed and accuracy are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of structural safety analysis, and in particular to a method for rapid prediction of the resistance of the side structure under a wedge-shaped bow impact scenario. Background Technology

[0002] Ship collisions pose a significant threat to maritime traffic safety, directly impacting navigational safety and potentially causing severe environmental pollution and ecological damage. While regulations and safety technologies are continuously being upgraded to reduce accident rates, research within the scope of structural safety assessment remains paramount. Especially in engineering applications, efficient analytical tools are crucial for both rapid damage prediction in accident scenarios and iterative optimization of crashworthiness during the design phase. Existing methods for ship collision structural safety analysis primarily include four main approaches: model testing, nonlinear finite element simulation, empirical formulas, and simplified analytical methods. Compared to other methods, simplified analytical methods, by establishing theoretical models that approximate actual deformation behavior and employing rigorous mathematical derivations, achieve rapid assessment while maintaining computational accuracy, providing an ideal solution for engineering applications.

[0003] Existing simplified analytical methods mostly focus on head-on collision scenarios. However, oblique collisions are more common in actual sea conditions, where colliding vessels strike the side of the target vessel at a certain angle (typically 15°-75°). This difference in collision angle leads to significant differences in structural response: in a head-on collision, the load is symmetrically distributed, and the structure mainly undergoes in-plane compressive deformation; while an oblique collision produces a complex combination of stress states, including axial compression, lateral shear, and torsional deformation. More importantly, the contact area exhibits dynamic changes under oblique impact conditions, and the collision energy is redistributed, resulting in structural damage modes that differ from those in head-on collisions.

[0004] While current research on oblique impact conditions has established simplified analytical models for the initial tearing stage of the outer plate, significant challenges remain in assessing the residual strength after penetration. This stems primarily from three technical difficulties: First, the outer plate after penetration exhibits a complex asymmetric tear propagation mode, with its crack propagation path influenced by multiple coupling factors including the impact angle, structural geometry, and material properties. Second, under large deformation conditions, the structure displays significant material and geometric nonlinear characteristics, rendering traditional small deformation theories inapplicable. More importantly, the tearing process of the outer plate caused by oblique impact is accompanied by dynamically changing contact areas and energy distribution mechanisms, further complicating the problem. These technical challenges make it difficult for existing analytical methods to accurately predict the structural resistance after penetration.

[0005] Therefore, those skilled in the art are dedicated to developing a rapid prediction method for the resistance of the side structure under a wedge-shaped bow impact scenario. Summary of the Invention

[0006] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present invention is that the outer plate frame of the side of the ship can still bear the load after tearing. For large impact depth scenarios such as the side structure continues to tear after being penetrated, the existing analytical prediction methods are difficult to accurately predict the structural resistance after penetration.

[0007] To achieve the above objectives, this invention provides a method for rapid prediction of the resistance of the side structure in a wedge-shaped bow impact scenario, the method comprising the following steps:

[0008] S101: Based on the wedge-shaped bow oblique collision scenario, the compartment structure system is decoupled into typical resistance units, and the deformation stage of the resistance units during the collision process is analyzed.

[0009] S103: Establish a simplified analytical model of the resistance element at different deformation stages under the collision scenario, and derive the analytical formula of the resistance element based on the upper bound theorem;

[0010] S105: The deformation damage resistance of the resistance unit is dynamically synthesized in time and space dimensions through a vector superposition algorithm;

[0011] S107: Based on the interaction between the various resistance units, the deformation damage resistance of each resistance unit is dynamically accumulated to achieve damage prediction of the entire compartment.

[0012] Further, in step S101, the resistance unit includes a side outer plating frame, side outer plating ribs, and a side deck plating frame, wherein,

[0013] The deformation stages of the outer side plate frame during the collision process include the plate stretching stage, the small tear penetration stage, and the tearing and curling stage.

[0014] The deformation mode of the outer side plating during the collision process mainly depends on the deformation of the outer side plating frame. The deformation stages of the outer side plating during the collision process include three stages: the stretching stage, the fracture stage, and the curling stage.

[0015] The deformation stages of the side deck frame during the collision process include the initial deformation stage and the tearing deformation stage.

[0016] Further, in step S103, during the plate stretching stage, the outer side plate frame forms a quadrangular pyramid shape with the impact point as its vertex. The deformation area is concave inward along the impact direction, resulting in membrane stretching deformation. The structural resistance generated by the membrane stretching deformation of the outer side plate frame is:

[0017] F=0.5N0(b1+b2)(sinθ1+sinθ2)

[0018] N0=σt

[0019] θ1 = arctan(δ / a1)

[0020] θ² = arctan(δ / a²)

[0021] Where F is the structural resistance, σ is the material flow stress, t is the plate thickness, and θ is the structural resistance. i (i = 1, 2, 3, 4) represents the instantaneous rotational velocity of the wedge-shaped bow deformation field boundary, δ represents the wedge-shaped bow impact depth, and a1, a2 and b1, b2 represent the distances of the wedge-shaped bow from the deformation field boundary.

[0022] Furthermore, during the small breach penetration stage, the membrane tensile deformation in the deformation area of ​​the hull side outer plating frame reaches its limit, and cracks appear from the impact point and expand to form a notch. The hull side outer plating frame still undergoes membrane tensile deformation, and slippage occurs in the deformation area and on the bow surface. The structural resistance generated by the hull side outer plating frame is:

[0023] F'=0.5N0(b1'+b2')(sinθ1'+sinθ2')

[0024] θ1' = arctan(δ' / a1)

[0025] θ2'=arctan(δ' / a2)

[0026] Where F' is the structural resistance, θ i '(i=1,2,3,4) represents the instantaneous rotational velocity of the wedge-shaped bow deformation field boundary after dynamic empirical correction, δ' represents the impact depth of the wedge-shaped bow after dynamic empirical correction, and b1', b2' represent the distances of the wedge-shaped bow from the deformation field boundary after dynamic empirical correction.

[0027] Furthermore, during the tearing and curling stage, as the impact depth of the wedge-shaped bow increases, the boundary line of the deformation area below the impact point continuously tears, and the torn plates undergo continuous curling deformation aft. The total resistance of the side outer plate frame in the oblique impact direction is:

[0028] F panel =F normal sinβ+F vertical cosβ

[0029]

[0030] F vertical =F friction =μF normal

[0031] Among them, F panel F is the total resistance of the outer panel frame in the oblique impact direction. vertical ,Ffriction F represents the frictional force between the wedge-shaped bow and the outer side plating. normal δ is the normal resistance generated by bending deformation and membrane tensile deformation. f This refers to the impact depth of the outer panel when it is penetrated through a small breach. R is the dip angle of the wedge-shaped bow along the impact depth direction. left R is the radius of curvature on the left. right α is the radius of curvature on the right side. l α is the angle of the left wedge-shaped bow perpendicular to the impact depth direction. r ε is the angle of the right-hand wedge-shaped bow perpendicular to the impact depth direction. f denoted as the failure strain of the material, μ as the total friction coefficient, and β as the angle of impact between the wedge-shaped bow and the rammed vessel.

[0032] Furthermore, when the hull side outer plate ribs are in the rib tension stage, the central ribs undergo both bending deformation and membrane tension deformation, while the side ribs mainly exhibit membrane tension deformation.

[0033] When the side outer plate frame is in the fracture stage, the central frame fractures and exhibits bending deformation, while the side frame continues to undergo membrane stretching deformation; when the break in the side outer plate frame extends to the side frame, the side frame transforms into a new central frame, and the deformation mode is consistent with that of the central frame.

[0034] When the outer hull plate is in the curling stage, the central rib curls along with the outer hull plate structure, and the deformation mode is mainly bending deformation. The side ribs in the non-direct collision area exhibit membrane stretching deformation.

[0035] Furthermore, during the tensile stage of the skeleton, the structural resistance generated by the central skeleton and the lateral skeleton is:

[0036]

[0037] During the curling stage, the total structural resistance of the hull side outer plate skeleton is:

[0038]

[0039] M1=σh1 2 / 4

[0040] M2=σt2 2 / 4

[0041] N1=σh1

[0042] N2=σt2

[0043] Among them, F S1 For the structural resistance generated by the central skeleton, F S2For the structural resistance generated by the lateral aggregate, F stiffeners Let be the total structural resistance of the side outer plating ribs, h1 be the height of the web of the rib structure, h2 be the height of the wing plate of the rib structure, t1 be the thickness of the web of the rib structure, t2 be the thickness of the wing plate of the rib structure, γ be a coefficient determined based on the distance of the side ribs from the collision point, R be the curl radius, and α be... left R is the radius of curvature on the left. right The radius of curvature on the right side is denoted as .

[0044] Furthermore, taking into account the plate-stirring coupling effect, the curl radius during the tearing deformation stage is modified to minimize the sum of the plastic resistance of the plate structure and the stiffener structure, thus obtaining the curl radius of the outer side plate when curling deformation occurs:

[0045]

[0046] Among them, R left R is the radius of curvature on the left. right n is the radius of curvature on the right side. left and n right These represent the number of bone components that participated in the deformation on the left and right sides of the collision point, respectively.

[0047] Furthermore, when the side deck frame encounters an impact load within the wedge-shaped bow face, based on the deformation mode, the side deck frame structure is divided into four types of components: horizontal smooth plates, transverse stiffeners, longitudinal T-shaped profiles, and cross-shaped structures.

[0048] The horizontal light plate undergoes small-scale crushing and wrinkling deformation in the initial deformation stage. When the horizontal light plate enters the tearing deformation stage, the deformation of the horizontal light plate is bending deformation and membrane stretching deformation.

[0049] The transverse reinforcing rib is attached to the horizontal plate, and the transverse reinforcing rib undergoes out-of-plane bending deformation. The plastic bending of the transverse reinforcing rib is concentrated on the plastic hinge line.

[0050] After being impacted by the wedge-shaped bow, the longitudinal T-profile undergoes a tearing and curling deformation.

[0051] The cross-shaped structure is configured as a cross-shaped component formed by the intersection of the outer plate stiffeners and the deck structure. When the cross-shaped structure is subjected to bow impact, it first undergoes yielding deformation, and then wrinkling deformation under pressure.

[0052] Furthermore, when the side deck frame encounters an impact load within the wedge-shaped bow face, the structural resistance generated by various components is as follows:

[0053] The structural resistance of the horizontal plate during the initial deformation stage is:

[0054]

[0055] The structural resistance of the horizontal plate during the tearing deformation stage is:

[0056]

[0057] The structural resistance of the transverse stiffener is:

[0058]

[0059] The structural resistance of the longitudinal T-section is:

[0060]

[0061] The structural resistance of the cross-shaped structure is:

[0062] F4=σ0(1.178(2b4t4 2 / H)+3Ht4+1.5t4 2 )

[0063] Where σ0 is the flow stress of the material, t1 is the thickness of the horizontal plate, b1 and b2 are the boundary lengths of the plate structure, and H is the characteristic height during crushing and wrinkling deformation.

[0064] μ is the coefficient of friction, θ is the angle between the wedge-shaped bow and the top view, R is the curl radius, and ε is the fracture strain of the material.

[0065] t s1 t s2 and t s The thicknesses h of the transverse stiffener web, face plate, and strip plate are respectively. s1 h s2 and h s3 These are the lengths of the plastic hinge lines of the web, face plate, and strip plate, respectively.

[0066] t t1 t t2 and t t The thicknesses h of the web, face plate, and strip of the longitudinal T-section are respectively. t1 h t2 and h t3 These are the lengths of the plastic hinge lines of the web, face plate, and strip plate, respectively.

[0067] b4 is the length of a single airfoil, and t4 is the thickness of a single airfoil.

[0068] In a preferred embodiment of the present invention, compared with the prior art, the present invention has the following beneficial effects:

[0069] 1. This invention establishes a simplified model of the plate and the frame and conducts theoretical derivation. By considering the asymmetric tearing and curling of the plate under oblique impact scenarios and the interaction between the frame and the plate, an analytical prediction model of tear damage resistance under this scenario is established. This fills the gap in the prediction of tear damage of the outer plate frame structure under oblique impact scenarios, realizes the complete prediction of the tear propagation behavior of the outer plate under oblique impact conditions, and provides key technical support for the overall crashworthiness assessment of the compartment.

[0070] 2. This invention decouples the complex compartment structure system into typical resistance units such as outer plates, decks, and transverse bulkheads, and draws on and establishes simplified analytical models of each component at different deformation stages.

[0071] 3. This invention utilizes a vector superposition algorithm to dynamically synthesize the deformation and damage resistance of each component across time and space, ultimately constructing a resistance curve that reflects the progressive failure process of the entire compartment. Considering multi-mode structural damage, it achieves rapid prediction of the overall compartment structural resistance under oblique collision scenarios, significantly improving the computational efficiency and accuracy of rapid engineering prediction of hull structural damage, and providing a reliable quantitative basis for optimized design of ship collision resistance.

[0072] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0073] Figure 1 This is a schematic diagram of the steps of a preferred embodiment of the rapid prediction method for the resistance of the side structure of the present invention;

[0074] Figure 2 This is a flowchart of the overall compartment damage prediction process according to a preferred embodiment of the present invention;

[0075] Figure 3 This is a schematic diagram of a typical component of a side structure according to a preferred embodiment of the present invention;

[0076] Figure 4 This is a simplified model schematic diagram of the stretching stage of the outer panel material according to a preferred embodiment of the present invention;

[0077] Figure 5 This is a simplified model diagram of the small tear penetration stage of the outer panel material according to a preferred embodiment of the present invention;

[0078] Figure 6 This is a simplified collision scenario and analytical model diagram of a preferred embodiment of the present invention, showing the tearing deformation of the outer plate with a large tear.

[0079] Figure 7 This is a simplified model schematic diagram of the bone stretching stage according to a preferred embodiment of the present invention;

[0080] Figure 8 This is a simplified model schematic diagram of the bone material curling stage of a preferred embodiment of the present invention;

[0081] Figure 9 This is a schematic diagram of the analytical calculation model of the deck components according to a preferred embodiment of the present invention;

[0082] Figure 10 This is a schematic diagram illustrating the collision condition definition of a preferred embodiment of the present invention;

[0083] Figure 11 This is a schematic diagram comparing the collision position 1 results of a preferred embodiment of the present invention;

[0084] Figure 12 This is a schematic diagram comparing the collision position 2 results of a preferred embodiment of the present invention;

[0085] Figure 13 This is a schematic diagram comparing the collision position 3 results of a preferred embodiment of the present invention. Detailed Implementation

[0086] The following description, with reference to the accompanying drawings, illustrates several preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0087] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of some components has been appropriately exaggerated in the drawings.

[0088] like Figure 1 As shown, for scenarios involving a wedge-shaped bow impacting a single-shell side at multiple angles, this invention proposes a simplified model and analytical prediction formula for the tearing stage of the side outer plating structure. By combining existing analytical model research results for various other components, it achieves analytical prediction of overall compartment structural damage. This invention provides a rapid prediction method for side structural resistance under a wedge-shaped bow impact scenario, comprising the following steps:

[0089] S101: Based on the oblique collision scenario of a wedge-shaped bow, the compartment structure system is decoupled into typical resistance elements, and the deformation stage of the resistance elements during the collision process is analyzed.

[0090] S103: Establish a simplified analytical model of the resistance element at different deformation stages under collision scenarios, and derive the analytical formula of the resistance element based on the upper bound theorem;

[0091] S105: The deformation and damage resistance of the resistance element is dynamically synthesized in time and space dimensions through a vector superposition algorithm;

[0092] S107: Based on the interaction between various resistance units, the deformation and damage resistance of each resistance unit is dynamically accumulated to achieve damage prediction of the entire compartment.

[0093] In this embodiment, the typical resistance units decoupled from the compartment structure system include the side outer plating frame, the side outer plating skeleton, and the side deck plating frame, wherein,

[0094] 1) The deformation stages of the outer plating frame of the side during the collision process include the plate stretching stage, the small hole penetration stage, and the tearing and curling stage.

[0095] 2) The deformation mode of the side outer plating skeleton during the collision process mainly depends on the deformation of the side outer plating frame. The deformation stages of the side outer plating skeleton during the collision process include three stages: the tensile stage, the fracture stage, and the curling stage.

[0096] 3) Side deck frame, during the deformation phase of the collision process, including the initial deformation phase and the tearing deformation phase.

[0097] Based on the specific deformation stages of each resistance unit during the collision process, this embodiment analyzes the deformation of each resistance unit and the structural resistance generated by the deformation.

[0098] 1. Deformation and structural resistance of the outer side plating frame at different stages.

[0099] 1) Sheet stretching stage

[0100] The outer plating frame of the hull side forms a four-sided pyramid shape with the point of impact as its vertex. The deformation area is concave inward along the impact direction, resulting in membrane tensile deformation. The structural resistance of the outer plating frame due to membrane tensile deformation is:

[0101] F=0.5N0(b1+b2)(sinθ1+sinθ2)

[0102] N0=σt

[0103] θ1 = arctan(δ / a1)

[0104] θ² = arctan(δ / a²)

[0105] Where F is the structural resistance, σ is the material flow stress, t is the plate thickness, and θ is the structural resistance. i (i = 1, 2, 3, 4) represents the instantaneous rotational velocity of the wedge-shaped bow deformation field boundary, δ represents the wedge-shaped bow impact depth, and a1, a2 and b1, b2 represent the distances of the wedge-shaped bow from the deformation field boundary.

[0106] 2) Small breach penetration stage

[0107] The membrane tensile deformation in the deformation zone reached its limit, and cracks appeared from the impact point and propagated to form a notch. The outer plating frame on the side of the ship continued to undergo membrane tensile deformation, and slippage occurred in the deformation zone and on the bow surface. The structural resistance generated by the outer plating frame on the side of the ship was:

[0108] F'=0.5N0(b1'+b2')(sinθ1'+sinθ2')

[0109] θ1' = arctan(δ' / a1)

[0110] θ2'=arctan(δ' / a2)

[0111] Where F' is the structural resistance, θ i '(i=1,2,3,4) represents the instantaneous rotational velocity of the wedge-shaped bow deformation field boundary after dynamic empirical correction, δ' represents the impact depth of the wedge-shaped bow after dynamic empirical correction, and b1', b2' represent the distances of the wedge-shaped bow from the deformation field boundary after dynamic empirical correction.

[0112] 3) Tearing and curling stage

[0113] As the impact depth of the wedge-shaped bow increases, the boundary line of the deformation zone below the impact point continues to tear, and the torn plates undergo continuous curling deformation aft. The total resistance of the outer plate frame on the side of the hull in the oblique impact direction is:

[0114] F panel =F normal sinβ+F vertical cosβ

[0115]

[0116]

[0117] F vertical =F friction =μF normal

[0118] Among them, F panel F is the total resistance of the outer panel frame in the oblique impact direction. vertical ,F friction F represents the frictional force between the wedge-shaped bow and the outer side plating. normal δ is the normal resistance generated by bending deformation and membrane tensile deformation. f This refers to the impact depth of the outer panel when it is penetrated through a small breach. R is the dip angle of the wedge-shaped bow along the impact depth direction. left R is the radius of curvature on the left. right α is the radius of curvature on the right side.l α is the angle of the left wedge-shaped bow perpendicular to the impact depth direction. r ε is the angle of the right-hand wedge-shaped bow perpendicular to the impact depth direction. f denoted as the failure strain of the material, μ as the total friction coefficient, and β as the angle of impact between the wedge-shaped bow and the rammed vessel.

[0119] 2. Deformation and structural resistance of the hull side outer plating skeleton at different stages

[0120] The deformation mode of the rib structure on the side plating mainly depends on the deformation of the plate structure, and can be divided into three stages: rib tension, fracture, and curling. Furthermore, based on the location of the ribs, they can be divided into central ribs in the direct impact zone and lateral ribs in the indirect impact zone.

[0121] 1) Bone stretching stage

[0122] The central aggregate undergoes both bending and membrane stretching deformation, while the lateral aggregates primarily exhibit membrane stretching deformation.

[0123] During the skeleton tensioning stage, the structural resistance generated by the central skeleton and the lateral skeletons is:

[0124]

[0125] 2) Fracture stage

[0126] When the outer plating of the side is in the fracture stage, the central plating fractures and undergoes bending deformation, while the side plating continues to undergo membrane tensile deformation. When the fracture of the outer plating extends to the side plating, the side plating transforms into a new central plating, and its deformation mode is consistent with that of the central plating.

[0127] 3) Curling stage

[0128] The central rib curls along with the outer plating structure of the side, with bending deformation being the main deformation mode. The side ribs in the non-direct collision area exhibit membrane stretching deformation.

[0129] The total structural resistance of the hull side outer plating is:

[0130]

[0131] M1=σh1 2 / 4

[0132] M2=σt2 2 / 4

[0133] N1=σh1

[0134] N2=σt2

[0135] Among them, F S1For the structural resistance generated by the central skeleton, F S2 For the structural resistance generated by the lateral aggregate, F stiffeners Let be the total structural resistance of the side outer plating ribs, h1 be the height of the web of the rib structure, h2 be the height of the wing plate of the rib structure, t1 be the thickness of the web of the rib structure, t2 be the thickness of the wing plate of the rib structure, γ be a coefficient determined based on the distance of the side ribs from the collision point, R be the curl radius, and α be... left R is the radius of curvature on the left. right The radius of curvature on the right side is denoted as .

[0136] In this embodiment, considering the plate-stirring coupling effect, the curl radius during the tearing deformation stage is modified to minimize the sum of the plastic resistance of the plate structure and the stiffener structure, thus obtaining the curl radius of the outer side plate when curling deformation occurs:

[0137]

[0138] Among them, R left R is the radius of curvature on the left. right n is the radius of curvature on the right side. left and n right These represent the number of bone components that participated in the deformation on the left and right sides of the collision point, respectively.

[0139] 3. Deformation and structural resistance of the deck structure at different stages

[0140] When a deck structure encounters an impact load within a wedge-shaped bow face, based on its structural deformation mode, the deck structure can be classified into four types of components: horizontal smooth plates, transverse stiffeners, longitudinal T-shaped profiles, and cross-shaped structures. Among these,

[0141] 1) Horizontal smooth plate

[0142] The deformation of the horizontal plate in the initial deformation stage is small-scale crushing and wrinkling deformation. When the horizontal plate enters the tearing deformation stage, the deformation of the horizontal plate is bending deformation and membrane stretching deformation.

[0143] The structural resistance of the horizontal plate during the initial deformation stage is:

[0144]

[0145] The structural resistance of the horizontal plate during the tearing deformation stage is:

[0146]

[0147] 2) Transverse stiffeners

[0148] The transverse stiffeners are attached to the horizontal smooth plate. The transverse stiffeners undergo out-of-plane bending deformation, and the plastic bending of the transverse stiffeners is concentrated on the plastic hinge line.

[0149] The structural resistance of the transverse stiffeners is:

[0150]

[0151] 3) Longitudinal T-shaped profiles

[0152] After being impacted by a wedge-shaped bow, the longitudinal T-section undergoes a tearing and curling deformation.

[0153] The structural resistance of the longitudinal T-section is:

[0154]

[0155] 4) Cross-shaped structure

[0156] The cross-shaped structure is used to describe the cross-shaped component formed by the intersection of the outer plate stiffeners and the deck structure. When the cross-shaped structure is subjected to bow impact, it first undergoes yielding deformation, and then wrinkling deformation under pressure.

[0157] The structural resistance of the cross-shaped structure is:

[0158] F4=σ0(1.178(2b4t4 2 / H)+3Ht4+1.5t4 2 )

[0159] Where σ0 is the flow stress of the material, t1 is the thickness of the horizontal plate, b1 and b2 are the boundary lengths of the plate structure, and H is the characteristic height during crushing and wrinkling deformation.

[0160] μ is the coefficient of friction, θ is the angle between the wedge-shaped bow and the top view, R is the curl radius, and ε is the fracture strain of the material.

[0161] t s1 t s2 and t s The thicknesses h of the transverse stiffener web, face plate, and strip plate are respectively. s1 h s2 and h s3 These are the lengths of the plastic hinge lines of the web, face plate, and strip plate, respectively.

[0162] t t1 t t2 and t t The thicknesses h of the web, face plate, and strip of the longitudinal T-section are respectively. t1 h t2 and h t3 These are the lengths of the plastic hinge lines of the web, face plate, and strip plate, respectively.

[0163] b4 is the length of a single airfoil, and t4 is the thickness of a single airfoil.

[0164] 4. Damage prediction for the entire compartment

[0165] This embodiment dynamically accumulates the deformation and damage resistance of each resistance unit based on the interaction between them, thereby achieving damage prediction for the entire compartment.

[0166] The prediction method employs an incremental step method for cumulative impact depth calculation. Specifically, the curl radius is corrected based on plate-stirrup coupling, and the mutual restraint effects between the outer plate, deck, and bulkheads are determined through cumulative impact depth and geometric relationships.

[0167] In each incremental step: First, the breach width is calculated in real time based on the impact angle and the geometric parameters of the wedge-shaped bow; then, adjacent undeformed strong members are found on both sides as the deformation boundary with the breach center as the reference, and multiple rib spacings are extended to both sides to determine the number of members involved in the deformation; finally, the failure strain threshold is set according to the material and the transformation of the structural deformation mode (from membrane tensile deformation to breach penetration, and from breach penetration to tearing and curling) is determined.

[0168] To predict collision damage to an overall compartment structure, this invention breaks it down into multiple typical components. By accumulating the deformation and damage resistance of each component and considering their mutual influence, the overall resistance is derived. Compared with existing technologies, this invention has the following characteristics:

[0169] 1. For scenarios involving large impact depths, such as the outer plating frame of the hull still bearing load after tearing, or the hull structure continuing to tear after being penetrated, existing analytical prediction methods still have gaps. This invention focuses on the tearing damage mode of the outer plating frame structure of the rammed ship after load-bearing failure in the oblique collision scenario with a wedge-shaped bow. A simplified model of the plate and the frame is established and theoretical derivation is carried out. By considering the asymmetric tearing and curling of the plate in the oblique collision scenario and the interaction between the frame and the plate, an analytical prediction model of tearing damage resistance in this scenario is established.

[0170] 2. This invention uses numerical simulation to observe the damage and deformation modes of various components during the tearing stage after the load-bearing structure is penetrated. The outer plate undergoes asymmetric curling deformation, which can be divided into bending deformation and membrane tensile deformation; the reinforcement also undergoes curling deformation along with the outer plate. Finally, considering the plate-reinforcement coupling effect, the curling radius during the tearing deformation stage is corrected, filling the gap in the prediction of tearing damage to the outer plate frame structure under oblique impact scenarios. This enables a complete prediction of the tear propagation behavior of the outer plate under oblique impact conditions, providing key technical support for the overall crashworthiness assessment of the compartment.

[0171] 3. In existing technologies, analytical prediction methods for the overall compartment structure in a wedge-shaped bow oblique collision scenario can only predict the initial tearing stage of the outer plating. They lack effective prediction methods for the progressive failure process of the overall compartment after penetration, as well as the nonlinear mechanical behavior of multiple components such as the outer plating, deck, and transverse bulkheads under large deformation conditions. To achieve collision damage prediction for the overall compartment structure in an oblique collision scenario, this invention decouples the complex compartment structure system into typical resistance units such as outer plating, deck, and transverse bulkheads, and establishes simplified analytical models of each component at different deformation stages. Through a vector superposition algorithm, the deformation damage resistance of each component is dynamically synthesized in time and space dimensions, ultimately constructing a resistance curve that reflects the progressive failure process of the overall compartment. The outer plating structure bears out-of-plane loads and experiences a tensile stage, a small-break penetration stage, and a tearing stage; the deck structure bears in-plane loads and experiences crushing, wrinkling, and tearing deformation stages. By establishing simplified analytical models of the plating and aggregate at different stages, analytical formulas for each component are derived based on the upper bound theorem. Finally, considering the interactions between various components, the deformation and damage resistance of each component is dynamically accumulated to achieve damage prediction for the entire compartment. Based on the consideration of multi-mode structural damage, rapid prediction of the structural resistance of the entire compartment under oblique collision scenarios is realized, which greatly improves the computational efficiency and accuracy of rapid engineering prediction of hull structural damage, and provides a reliable quantitative basis for the optimized design of ship collision resistance performance.

[0172] The present invention will now be described in detail with reference to preferred embodiments.

[0173] This invention addresses the oblique collision scenario involving a wedge-shaped bow by establishing an analytical prediction model for the tear damage resistance of the outer plating structure on the side of the collided vessel after load-bearing failure. Combined with prediction models for other side components, a comprehensive structural resistance assessment system considering multi-mode damage is constructed. This achieves accurate prediction of the resistance characteristics and energy absorption capacity of the side structure throughout the entire oblique collision process, significantly improving the speed and accuracy of collision damage prediction in engineering practice.

[0174] To predict collision damage to an integral compartment structure, it is typically broken down into multiple typical components. The overall resistance is calculated by summing the deformation damage resistance of each component and considering their interrelationships. Typical side structures include outer plating frames, deck plating frames, strong trusses, and intersecting structures formed at the junctions of strong longitudinal and transverse structures, such as... Figure 3 As shown, this invention divides the side structure into two parts: the outer plate frame and the deck plates. Based on the deformation modes of each component at different damage stages and considering the interaction between components, the corresponding analytical expression for structural resistance is derived.

[0175] The method for rapid prediction of the resistance of the side structure in the scenario of a wedge-shaped bow collision provided by this invention is as follows.

[0176] (1) Analytical model of the outer plate frame of the side plate

[0177] This invention establishes an analytical prediction model for the tensile stage, small tear penetration stage, and tearing and curling stage of the outer hull plate. When the bow of the impacting vessel just touches the hull structure, the outer plate forms a square pyramid shape with the impact point as the vertex. The four deformation regions, I, II, III, and VI, will indent inward along the impact direction, undergoing membrane tensile deformation, such as... Figure 4 As shown.

[0178] exist Figure 4 In the diagram, β is the impact angle; δ is the impact depth of the wedge-shaped bow; Δ is the vertical distance from the tip of the wedge-shaped bow to the outer plate boundary; L left and L right θ represents the breach lengths from the tip of the wedge-shaped bow to the left and right boundaries, respectively; i (i = 1, 2, 3, 4) represents the instantaneous rotational velocity of the deformation field boundary of the wedge-shaped bow; a1, a2 and b1, b2 are the distances of the wedge-shaped bow from the deformation field boundary. The structural resistance generated by the membrane tensile deformation during the tensile stage of the outer side plate is as follows:

[0179] F=0.5N0(b1+b2)(sinθ1+sinθ2) (1)

[0180] In the formula, N0 = σt; σ is the flow stress of the material; t is the plate thickness; θ1 = arctan(δ / a1); θ2 = arctan(δ / a2).

[0181] As the impact depth increases, the membrane stretching deformation in the four deformation zones reaches its limit. Cracks appear and propagate from the impact point, forming a notch, entering the small-fracture penetration stage, such as... Figure 5 As shown. At this point, the outer plating still undergoes membrane tensile deformation, but the wedge-shaped bow intrudes into the hull, and there is some slippage in the deformation area and on the bow surface. Therefore, after dynamic empirical correction of the impact depth term δ and the boundary term b, δ' and b' are obtained. The analytical calculation formula for the structural resistance of the side outer plating frame at this stage is as follows:

[0182] F'=0.5N0(b1'+b2')(sinθ1'+sinθ2') (2)

[0183] In the formula, θ1' = arctan(δ' / a1), θ2' = arctan(δ' / a2). When the membrane tension in deformation regions I and II reaches its limit, new vertical cracks will appear near the impact point of the wedge-shaped bow and propagate downwards along the height direction, and the outer plate frame will enter the tearing stage. A simplified collision scenario and analytical model are established based on its deformation characteristics and geometric relationships, such as... Figure 6 As shown.

[0184] Energy dissipation primarily originates from three aspects. First, as the impact depth of the wedge-shaped bow increases, the boundary line of the deformation zone below the impact point will continuously tear, and the torn plates will undergo continuous curling deformation aft. The energy dissipation mainly comes from the bending deformation of the outer plate structure. Second, the vertical crack below the impact point gradually expands, and point F is compressed by the bow, causing it to move away from the plane of the outer plate on the side of the hull. This leads to tensile deformation in the BCD region, and the energy dissipation in this process is the membrane tensile deformation of the outer plate structure. Finally, the outer plate on the side of the hull is in close contact with the surface of the wedge-shaped bow, and friction occurs between them. The energy dissipation comes from frictional energy.

[0185] Based on the upper bound theorem of plasticity, the simplified model of large-break tearing deformation of the outer plate, and geometric relationships, the normal resistance generated by bending deformation and membrane tensile deformation of the side plate during the large-break tearing deformation stage is derived, and its expression is:

[0186]

[0187] In the formula, δ f This refers to the impact depth of the outer panel when it penetrates through a small breach. R is the dip angle of the wedge-shaped bow along the impact depth direction. left and R right The curl radii for the left and right sides are given after comprehensively considering the plate-stirrup coupling effect and adjusting for the structural resistance of the outer plate ribs; α left and α right These are the angles of the left and right wedge-shaped bows perpendicular to the impact depth direction, respectively; ε f β represents the failure strain of the material, and β is the angle of impact between the wedge-shaped bow and the rammed vessel.

[0188] As the angled impact depth of a wedge-shaped bow increases, the hull plating, deck, and transverse bulkheads exert a tangential structural resistance on the ship. Assuming the total coefficient of friction is μ, the frictional force between the wedge-shaped bow and the hull plating can be expressed as F. vertical =F friction =μF normal Combining normal drag and frictional drag, the total drag provided by the plate structure in the oblique impact direction during the tearing and curling stage after load penetration of the hull side outer plate can be expressed as:

[0189] F panel =F normal sinβ+F vertical cosβ (4)

[0190] The deformation mode of the rib structure on the side plating mainly depends on the deformation of the plate structure, and can be divided into three stages: rib tension, fracture, and curling. Furthermore, based on the location of the ribs, they can be divided into central ribs in the direct impact zone and lateral ribs in the indirect impact zone.

[0191] During the stretching stage of the skeleton, the central skeleton undergoes both bending and membrane stretching deformation, while the lateral skeletons primarily exhibit membrane stretching deformation. A simplified model is shown below. Figure 7 As shown.

[0192] The structural resistance generated by the central and lateral ribs are F S1 and F S2 :

[0193]

[0194] In the formula, h1, h2 and t1, t2 are the height and thickness of the web and flange of the skeleton structure, respectively; M1 = σh1 2 / 4;M2=σt2 2 / 4; N1=σh1; N2=σt2; γ is a coefficient determined based on the position of the lateral bone material at the point of impact.

[0195] As the impact depth of the ramming vessel increased, the central rib fractured, subsequently exhibiting primarily bending deformation; while the lateral ribs continued to undergo membrane tensile deformation. When the breach in the side plating extended to the lateral ribs, the lateral ribs transformed into new central ribs, exhibiting the same deformation pattern as the central ribs.

[0196] When the outer side plating enters the large-break tearing deformation stage, the central rib curls along with the outer side plating structure, and its deformation mode is mainly bending deformation. A simplified model is shown below. Figure 8 As shown, by simplifying the continuous curling deformation of the stiffener into bending deformation around a movable plastic hinge, the expression for the structural resistance F generated by the bending deformation of the skeleton can be derived. S1 .

[0197] In the indirect collision zone, the lateral ribs mainly exhibit membrane tensile deformation. By adding the structural resistance of the central ribs and the lateral ribs, the total structural resistance of the hull side outer plate ribs during the curling stage can be obtained:

[0198]

[0199] In the formula, R = 0.5(R left +R right ), representing the curl radius of the steel reinforcement at the point of impact between the wedge-shaped bow and the outer side plating; n left and n right These represent the number of bone components involved in the deformation when curling deformation occurs on the left and right sides, respectively.

[0200] This invention comprehensively considers the plate-stirring coupling effect and modifies the curl radius during the tearing deformation stage to minimize the sum of the plastic resistance of the plate structure and the stiffener structure, thus obtaining the curl radius of the outer side plate when curling deformation occurs:

[0201]

[0202] The curl radius R left and R right Substitute F panel (Formula (2)) and F stiffeners In the analytical calculation formula of (Formula (3)), the structural resistance generated by the deformation of the outer plate frame structure during the large tear stage can be obtained.

[0203] (2) Analytical model of the side deck frame

[0204] When the deck structure encounters an impact load within the wedge-shaped bow face, based on its structural deformation mode, the deck structure can be divided into four types of components: horizontal smooth plates, transverse stiffeners, longitudinal T-shaped profiles, and cross-shaped structures. The analytical calculation models for these four types of components are as follows: Figure 9 As shown.

[0205] The horizontal plate exhibits small-scale crushing wrinkles during the initial deformation stage, such as... Figure 9 As shown in (a), the expression for structural resistance is as follows:

[0206]

[0207] In the formula, σ0 is the flow stress of the material; t is the thickness of the horizontal plate; b1 and b2 are the boundary lengths of the plate structure; H is the characteristic height during crushing and wrinkling deformation, which can be expressed as... Moreover, the impact depth satisfies 0≤δ≤7H.

[0208] Driven by the wedge-shaped bow, the plates at the bow tip reach the critical fracture strain and tear, continuously curling outwards at the tip to form two curved surfaces. The horizontal smooth plate then enters the tearing deformation stage, the theoretical analytical model of which is as follows: Figure 9 As shown in (b). This stage is mainly characterized by bending deformation and membrane tensile deformation, and the structural resistance can be expressed as:

[0209]

[0210] In the formula, μ is the friction coefficient; θ is the angle between the wedge-shaped bow and the top view; the curl radius R is given after comprehensively considering the plate-stirrup coupling effect and combining it with the structural resistance of the transverse stiffeners; and ε is the fracture strain of the material.

[0211] The transverse stiffeners, attached to the horizontal smooth plate, generally undergo out-of-plane bending deformation. In the simplified analytical model, the plastic bending of the transverse stiffeners is concentrated along the movable plastic hinge line, such as... Figure 9 As shown in (c), its structural resistance F2 can be expressed as:

[0212]

[0213] In the formula, t s1 t s2 t and h represent the thicknesses of the web, face plate, and strip plate of the transverse stiffener, respectively. s1 h s2 and h s3 These are the lengths of the plastic hinge lines of the web, face plate, and strip plate, respectively.

[0214] Taking the partial derivative of the sum of the structural resistance of the plate structure and the transverse stiffeners, and setting it to zero, we can obtain the optimal curl radius R considering the plate-stiffener coupling effect:

[0215]

[0216] In the formula, S is only related to the geometric dimensions of the bone material, and can be expressed as:

[0217]

[0218] The longitudinal T-section is located far from the hull side and has no significant impact on the deformation of the deck structure before direct contact with the bow. When the longitudinal T-section is impacted by the wedge-shaped bow, its deformation mode is mainly tearing and curling, and its simplified analytical model is as follows: Figure 9 As shown in (d), the structural resistance F3 can be expressed as:

[0219]

[0220] In the formula, t t1 t t2 t and h represent the thicknesses of the web, face, and strip of the longitudinal T-section, respectively. t1 h t2 and h t3 These are the lengths of the plastic hinge lines of the web, face plate, and strip plate, respectively.

[0221] The term "cross-shaped structure" describes a cross-shaped member formed by the intersection of the outer plating stiffeners and the deck structure. When subjected to bow impact, the cross-shaped structure first yields, then wrinkles under compression, as shown in the image. Figure 9 As shown in (e), the specific expression is:

[0222] F4=σ0(1.178(2bt 2 / H)+3Ht+1.5t 2 (16)

[0223] In the formula, 2H represents the height of each fold, and the calculation expression is 2H = 1.77b. 1.5 / t 0.5 , b represents the length of a single wingplate, and t represents the thickness of a single wingplate.

[0224] Based on the analytical formula for structural resistance during the tearing deformation stage of the side outer plating derived in this invention, and combined with the analytical model of other side components, a structural resistance prediction model for the entire compartment can be established considering multi-mode structural damage and multi-angle collision scenarios. The prediction process is as follows: Figure 2 As shown.

[0225] like Figure 2 As shown, the prediction method in this embodiment uses the incremental step method to calculate the cumulative impact depth. The step size is Δd = 0.01m, and the curl radius is corrected based on the plate-stirrup coupling effect. The mutual restraint between the outer plate, deck, and bulkhead is determined by the cumulative impact depth and geometric relationships.

[0226] In each incremental step: First, the breach width is calculated in real time based on the impact angle and the geometric parameters of the wedge-shaped bow; then, adjacent undeformed strong members are found on both sides of the breach center as the deformation boundary, and the number of members involved in the deformation is determined by expanding to both sides by 2 rib spacings (about 1.3m); finally, the failure strain threshold is set according to the material and the transformation of the structural deformation mode (from membrane tensile deformation to breach penetration, and from breach penetration to tearing and curling) is determined.

[0227] (3) Numerical verification

[0228] To verify the accuracy of the analytical method for predicting the tearing of the outer plate frame under multi-angle collision scenarios of a wedge-shaped bow, this invention uses the nonlinear finite element method to numerically simulate the scenario of a wedge-shaped bow impacting a single-shell hull side structure at multiple angles, extracting structural resistance and energy dissipation data from the simulation, and comparing and verifying the results with those of the analytical method.

[0229] The collision points are located on the centerline of the longitudinal compartment. Based on the tonnage and relative draft of the two ships, three collision points are set in the height direction, such as... Figure 10 As shown in (a), the wedge-shaped bow impacted at angles of 75°, 60°, 45°, and 30° at each collision location, as shown in [the diagram]. Figure 10 As shown in (b). There are a total of 12 operating conditions, as shown in Table 1.

[0230] Table 1 Collision Conditions

[0231]

[0232]

[0233] For the aforementioned 12 working conditions, the analytical prediction model and finite element simulation constructed in this invention were used for calculation. First, the structural resistance-impact depth curves were compared and analyzed. Since structural resistance fluctuates significantly during the collision process, in practical engineering applications, external dynamic analysis is usually combined with the magnitude and pattern of energy dissipation to determine the impact depth of the side structure. Therefore, this invention further integrates the structural resistance to obtain the energy dissipation-impact depth curve, which is then compared and verified with the simulation results. The comparison results for the three collision locations are as follows: Figure 11 , Figure 12 and Figure 13 As shown.

[0234] from Figure 11 , Figure 12 and Figure 13 It can be seen that the analytical method of this invention can accurately reflect the transformation of the cabin deformation stage and the energy dissipation in different deformation stages. The analytical prediction model and the numerical simulation results are consistent in the overall trend and values ​​of structural resistance and energy dissipation. To verify the accuracy of this analytical prediction method, the prediction accuracy of the model was systematically evaluated by comparing the energy dissipation values ​​calculated by the analytical method and numerical simulation at different impact depths. The study adopted the equidistant sampling method, selecting 8 feature points every 0.5m within the 0-4m impact depth range for comparative analysis. Through statistical analysis of test data from 12 different collision conditions (including multi-angle and multi-position collision conditions), after removing the maximum and minimum values, the average value of the relative error of energy dissipation of the two methods was calculated, as shown below:

[0235]

[0236] In the formula, E i and E' i The energy dissipation values ​​are obtained from analytical methods and numerical simulations, respectively. The results show that the average relative error between the analytical method and the numerical simulation results is within 17%, effectively characterizing the overall agreement between the two curves across the entire impact depth range. Particularly noteworthy is that the prediction accuracy of the analytical method gradually improves with increasing impact depth: when the impact depth reaches 4m (the stage of large structural deformation), the average relative error further decreases to 10%, fully verifying the superior prediction performance of the analytical method under large deformation conditions. Considering the complexity of ship collision problems and the generally accepted error range in engineering practice, a prediction error within 20% fully meets the needs of practical engineering applications. Especially in the scenario of large impact depths where the outer plating continues to tear after being penetrated by the load, this method exhibits higher prediction accuracy, providing reliable technical support for engineering applications.

[0237] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for rapid prediction of the resistance of the hull side structure under a wedge-shaped bow impact scenario, characterized in that, The method includes the following steps: S101: Based on the wedge-shaped bow oblique collision scenario, the compartment structure system is decoupled into typical resistance units, and the deformation stage of the resistance units during the collision process is analyzed. S103: Establish a simplified analytical model of the resistance element at different deformation stages under the collision scenario, and derive the analytical formula of the resistance element based on the upper bound theorem; S105: The deformation damage resistance of the resistance unit is dynamically synthesized in time and space dimensions through a vector superposition algorithm; S107: Based on the interaction between the various resistance units, the deformation damage resistance of each resistance unit is dynamically accumulated to achieve damage prediction of the entire compartment.

2. The method as described in claim 1, characterized in that, In step S101, the resistance unit includes a side outer plating frame, side outer plating ribs, and side deck plating frame, wherein, The deformation stages of the outer side plate frame during the collision process include the plate stretching stage, the small tear penetration stage, and the tearing and curling stage. The deformation mode of the outer side plating during the collision process mainly depends on the deformation of the outer side plating frame. The deformation stages of the outer side plating during the collision process include three stages: the stretching stage, the fracture stage, and the curling stage. The deformation stages of the side deck frame during the collision process include the initial deformation stage and the tearing deformation stage.

3. The method as described in claim 2, characterized in that, In step S103, during the plate stretching stage, the outer side plate frame forms a quadrangular pyramid shape with the impact point as its vertex. The deformation area is concave inward along the impact direction, resulting in membrane stretching deformation. The structural resistance generated by the membrane stretching deformation of the outer side plate frame is: F=0.5N0(b1+b2)(sinθ1+sinθ2) N0=σt θ1 = arctan(δ / a1) θ² = arctan(δ / a²) Where F is the structural resistance, σ is the material flow stress, t is the plate thickness, and θ is the structural resistance. i (i = 1, 2, 3, 4) represents the instantaneous rotational velocity of the wedge-shaped bow deformation field boundary, δ represents the wedge-shaped bow impact depth, and a1, a2 and b1, b2 represent the distances of the wedge-shaped bow from the deformation field boundary.

4. The method as described in claim 3, characterized in that, During the small breach penetration stage, the membrane tensile deformation in the deformation area of ​​the outer side plating frame reaches its limit, and the crack appears from the impact point and expands to form a notch. The outer side plating frame still undergoes membrane tensile deformation, and slippage occurs in the deformation area and on the bow surface. The structural resistance generated by the outer side plating frame is: F'=0.5N0(b1'+b2')(sinθ1'+sinθ2') θ1' = arctan(δ' / a1) θ2'=arctan(δ' / a2) Where F' is the structural resistance, θ i '(i=1,2,3,4) represents the instantaneous rotational velocity of the wedge-shaped bow deformation field boundary after dynamic empirical correction, δ' represents the impact depth of the wedge-shaped bow after dynamic empirical correction, and b1', b2' represent the distances of the wedge-shaped bow from the deformation field boundary after dynamic empirical correction.

5. The method as described in claim 4, characterized in that, During the tearing and curling stage, as the impact depth of the wedge-shaped bow increases, the boundary line of the deformation zone below the impact point continuously tears, and the torn plates undergo continuous curling deformation aft. The total resistance of the side outer plate frame in the oblique impact direction is: F panel =F normal sinβ+F vertical cosβ F vertical =F friction =μF normal Among them, F panel F is the total resistance of the outer panel frame in the oblique impact direction. vertical ,F friction F represents the frictional force between the wedge-shaped bow and the outer side plating. normal δ is the normal resistance generated by bending deformation and membrane tensile deformation. f This refers to the impact depth of the outer panel when it is penetrated through a small breach. R is the dip angle of the wedge-shaped bow along the impact depth direction. left R is the radius of curvature on the left. right α is the radius of curvature on the right side. l α is the angle of the left wedge-shaped bow perpendicular to the impact depth direction. r ε is the angle of the right-hand wedge-shaped bow perpendicular to the impact depth direction. f denoted as the failure strain of the material, μ as the total friction coefficient, and β as the angle of impact between the wedge-shaped bow and the rammed vessel.

6. The method as described in claim 5, characterized in that, When the hull side outer plate ribs are in the rib tension stage, the central ribs undergo both bending deformation and membrane tension deformation, while the side ribs mainly exhibit membrane tension deformation. When the side outer plate frame is in the fracture stage, the central frame fractures and exhibits bending deformation, while the side frame continues to undergo membrane stretching deformation; when the break in the side outer plate frame extends to the side frame, the side frame transforms into a new central frame, and the deformation mode is consistent with that of the central frame. When the outer hull plate is in the curling stage, the central rib curls along with the outer hull plate structure, and the deformation mode is mainly bending deformation. The side ribs in the non-direct collision area exhibit membrane stretching deformation.

7. The method as described in claim 6, characterized in that, During the tensile stage of the skeleton, the structural resistance generated by the central skeleton and the lateral skeleton is: During the curling stage, the total structural resistance of the hull side outer plate skeleton is: M1=σh1 2 / 4 M2=σt2 2 / 4 N1=σh1 N2=σt2 Among them, F S1 For the structural resistance generated by the central skeleton, F S2 For the structural resistance generated by the lateral aggregate, F stiffeners Let be the total structural resistance of the side outer plating ribs, h1 be the height of the web of the rib structure, h2 be the height of the wing plate of the rib structure, t1 be the thickness of the web of the rib structure, t2 be the thickness of the wing plate of the rib structure, γ be a coefficient determined based on the distance of the side ribs from the collision point, R be the curl radius, and α be... left R is the radius of curvature on the left. right The radius of curvature on the right side.

8. The method as described in claim 7, characterized in that, Taking into account the plate-stirring coupling effect, the curl radius during the tearing deformation stage is modified to minimize the sum of the plastic resistance of the plate structure and the stiffener structure, thus obtaining the curl radius of the outer side plate when curling deformation occurs: Among them, R left R is the radius of curvature on the left. right n is the radius of curvature on the right side. left and n right These represent the number of bone components that participated in the deformation on the left and right sides of the collision point, respectively.

9. The method as described in claim 8, characterized in that, When the side deck frame encounters an impact load within the wedge-shaped bow face, based on the deformation mode, the side deck frame structure is divided into four types of components: horizontal smooth plates, transverse stiffeners, longitudinal T-shaped profiles, and cross-shaped structures. The horizontal light plate undergoes small-scale crushing and wrinkling deformation in the initial deformation stage. When the horizontal light plate enters the tearing deformation stage, the deformation of the horizontal light plate is bending deformation and membrane stretching deformation. The transverse reinforcing rib is attached to the horizontal plate, and the transverse reinforcing rib undergoes out-of-plane bending deformation. The plastic bending of the transverse reinforcing rib is concentrated on the plastic hinge line. After being impacted by the wedge-shaped bow, the longitudinal T-profile undergoes a tearing and curling deformation. The cross-shaped structure is configured as a cross-shaped component formed by the intersection of the outer plate stiffeners and the deck structure. When the cross-shaped structure is subjected to bow impact, it first undergoes yielding deformation, and then wrinkles under pressure.

10. The method as described in claim 9, characterized in that, When the side deck frame encounters an impact load within the wedge-shaped bow face, the structural resistance generated by various components is as follows: The structural resistance of the horizontal plate during the initial deformation stage is: The structural resistance of the horizontal plate during the tearing deformation stage is: The structural resistance of the transverse stiffener is: The structural resistance of the longitudinal T-section is: The structural resistance of the cross-shaped structure is: F4=σ0(1.178(2b4t4 2 / H)+3Ht4+1.5t4 2 ) Where σ0 is the flow stress of the material, t1 is the thickness of the horizontal plate, b1 and b2 are the boundary lengths of the plate structure, and H is the characteristic height during crushing and wrinkling deformation. μ is the coefficient of friction, θ is the angle between the wedge-shaped bow and the top view, R is the curl radius, and ε is the fracture strain of the material. t s1 t s2 and t s The thicknesses h of the transverse stiffener web, face plate, and strip plate are respectively. s1 h s2 and h s3 These are the lengths of the plastic hinge lines of the web, face plate, and strip plate, respectively. t t1 t t2 and t t The thicknesses h of the web, face plate, and strip of the longitudinal T-section are respectively. t1 h t2 and h t3 These are the lengths of the plastic hinge lines of the web, face plate, and strip plate, respectively. b4 is the length of a single airfoil, and t4 is the thickness of a single airfoil.

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