Method and system for analyzing pressure of external liquid storage structure under action of explosive shock wave load

Abstract

The invention belongs to the technical field of pressure analysis, and discloses a pressure analysis method for an external liquid storage structure under the action of an explosive shock wave load, which comprises the following steps: analyzing the dynamic response process of the external liquid storage structure under the action of the explosive shock wave load according to the dynamic response process of a non-liquid-storage structure, and theoretically calculating and solving the dynamic response process of the external liquid storage structure. The displacement and deformation theoretical solution of the external liquid storage structure is obtained, and the calculation time is greatly shortened. The method comprises the following steps: establishing a structural dynamic response theoretical model of an external liquid storage structure under the action of explosive shock wave load, taking a liquid storage container and a liquid medium as the additional mass mw of the structure, determining a structural dynamic response process according to the thickness of a liquid layer and considering the restrictive action time of the liquid medium on structural deformation, and calculating the structural dynamic response by solving a structural displacement solution. The deformation condition of the external liquid storage structure under the action of the explosive shock wave load is obtained, the solving efficiency is greatly improved, and the defects that finite element simulation solving is low in efficiency and long in consumed time are overcome.

Description

Technical Field

[0001] The present invention belongs to the technical field of pressure analysis, and particularly relates to a method and a system for analyzing the pressure of an external liquid storage structure under the action of an explosion shock wave load. Background Art

[0002] In many fields such as energy engineering, civil engineering, and ship and ocean engineering, liquid storage cylindrical shell structures are widely used. Under the damage of explosives such as shell charges, prefabricated fragment charges, and improvised explosive devices (IEDs), liquid storage cylindrical shell structures such as fuel storage tanks, liquid pipelines, and liquid storage explosion-proof containers will be subjected to the combined action of explosion shock waves and high-speed fragment groups, resulting in elastoplastic deformation, perforation, tearing, large-area rupture and other damages, and the structural safety and facility viability are thus seriously threatened. The liquid medium can effectively improve the protection performance of the structure against the combined action of explosion shock waves and high-speed fragment groups. At present, scholars have carried out many studies on the dynamic response characteristics of liquid storage cylindrical shell structures under the combined action of explosion shock waves and high-speed fragment groups. For example, Wu et al. used the method of driving prefabricated fragments with charges to carry out research on the damage characteristics of polyurea-coated liquid storage pipes under the combined action of explosion shock waves and high-speed fragment groups. However, due to the relatively long explosion distance, the damage ability of the shock wave to the structure is weak. For the problem of damaging liquid storage cylindrical shells under the combined action of explosion shock waves and high-speed fragment groups dominated by explosion shock waves, Zhou et al. used the method of detonating explosives inside the structure to carry out research on the anti-explosion protection characteristics of an annular flexible water layer, and found that the liquid medium can effectively hinder the radial transmission of explosion shock waves; Zhu et al. further studied the protection mechanism of the annular flexible water layer against the combined action of explosion shock waves and high-speed fragment groups under internal explosion, and found that the water layer design should mainly focus on the anti-explosion requirements of the structure; on this basis, Yang et al. placed the liquid storage water layer inside a metal cylindrical container and studied the influence of the liquid layer size on the anti-explosion protection performance of the cylindrical container, and found that the liquid layer can effectively improve the anti-explosion performance of the cylindrical container. Generally speaking, the current research mainly focuses on the dynamic response characteristics of flexible liquid layers under the combined action of explosion shock waves and high-speed fragment groups, and the dynamic response characteristics of internal liquid storage structures under the action of explosion shock waves, and there is no research on the dynamic response characteristics of external liquid storage structures under the action of explosion shock wave loads and its theoretical solution model. According to the analysis of numerical simulation results, the use of the form of external liquid storage structures can greatly improve the anti-explosion protection performance of liquid storage cylindrical shells. However, at present, only numerical simulation analysis can be carried out through finite element simulation software, and its calculation process has a long time span, low efficiency, and high cost.

[0003] The following technical problems exist in the prior art in the pressure analysis of explosion shock wave loads of external liquid storage explosion-proof structures:

[0004] 1. Dependence on the complexity of traditional finite element simulation calculations

[0005] The current analysis method mainly relies on finite element simulation technology, with complex modeling and calculation processes, making it difficult to obtain accurate results in a short time.

[0006] 2. Low computational efficiency and long time consumption

[0007] Due to the large number of iterations and computational resources required by traditional simulations, the analysis period is relatively long, unable to meet the needs of rapid evaluation and design optimization.

[0008] 3. Lack of quantitative analysis method for the constraint effect of liquid medium

[0009] Existing technologies lack theoretical model support for the additional mass and constraint effect of liquid medium in explosion-proof structures, and are unable to accurately evaluate the impact of liquid layer thickness on the dynamic response of structures.

[0010] 4. Difficulty in providing efficient pressure distribution and dynamic response evaluation

[0011] In existing methods, the evaluation of the dynamic response of pressure distribution and structural deformation relies on cumbersome calculations and lacks support from fast and concise theoretical calculation models. Summary of the Invention

[0012] In view of the problems existing in the prior art, the present invention provides a method for analyzing the pressure of an external liquid storage structure under the action of an explosion shock wave load.

[0013] The present invention is implemented as follows. A method for analyzing the pressure of an external liquid storage structure under the action of an explosion shock wave load includes:

[0014] Step 1: Establish a theoretical model of the structural dynamic response of an external liquid storage structure under the action of an explosion shock wave load;

[0015] Step 2: Regard the liquid storage container and the liquid medium as the additional mass m of the structure w , and determine the structural dynamic response process according to the liquid layer thickness, considering the time of the constraint effect of the liquid medium on the structural deformation;

[0016] Step 3: Solve the structural displacement solution to obtain the deformation of the external liquid storage structure under the action of an explosion shock wave load.

[0017] Furthermore, regarding the liquid storage container and the liquid medium as the additional mass m of the structure w , and determining the structural dynamic response process according to the liquid layer thickness, considering the time of the constraint effect of the liquid medium on the structural deformation:

[0018] For the external liquid storage structure under the action of an explosion shock wave, the following design can be carried out. Regard the liquid medium and the liquid storage structure as the additional mass m of the structure w , and when considering the constraint effect of the liquid medium on the structural deformation, it is necessary to use the equivalent mass ms Revised to the revised equivalent mass m m :

[0019] m m = m e + m w = ρ s h s + ρ w h w + ρ p h p (1)

[0020] Among them, ρ p is the density of the liquid medium, and h p is the liquid layer thickness; the restriction action time t w of the liquid medium can be obtained from the following formula:

[0021]

[0022] According to the analysis of the above formula, the restriction action time (t w ) of the liquid medium and the liquid layer thickness (h p ) are positively correlated, indicating that the liquid layer thickness (h p ) has a significant impact on the dynamic response process of the structure; therefore, it is necessary to conduct a classification discussion around the restriction action time (t w ) of the liquid medium, the structural yield time (t p ) and the end time (t f ) of the impact load action;

[0023] When the liquid layer thickness is relatively thin, the restriction action time of the liquid medium on the structural deformation is earlier than the occurrence of plastic deformation of the structure (Mode 1), that is, it satisfies t w < t p < t f ; in this case, the dynamic response process of the structure can be divided into four stages:

[0024] The first stage is the elastic forced vibration of the cylindrical shell under the restriction of the liquid;

[0025] The second stage is the elastic forced vibration of the cylindrical shell without liquid restriction;

[0026] The third stage is the plastic forced vibration of the cylindrical shell without liquid restriction;

[0027] The fourth stage is the plastic free vibration of the cylindrical shell without liquid restriction;

[0028] The theoretical model of this process can be described by formula (3);

[0029]

[0030] For the first stage (0 to tw ) The displacement y of the structure can be obtained by solving according to Equation (6). aI (t) and the velocity v aI (t):

[0031]

[0032] Where, ω yw is the elastic vibration frequency of the structure under the liquid restraint action and can be expressed by the following formula:

[0033]

[0034] Coefficients C a1 and C a2 can be obtained from the initial boundary conditions (y(0) = 0, v(0) = 0):

[0035]

[0036] Substituting t w into Equations (4)-(5), the structural deformation y w and the velocity v w at the moment when the liquid restraint action disappears can be solved; for the second stage (t w to t p ), the displacement y aII (t) and the velocity v aII (t) of the structure can be obtained by solving according to Equation (6):

[0037]

[0038] Coefficients C a3 and C a4 can be obtained from the boundary conditions (y (tw) = y w , v (tw) = v w ):

[0039]

[0040] Substituting y p into Equations (9)-(10), the moment t p when the structure begins to undergo plastic deformation and the velocity v p can be solved; for the third stage (t p to t f ), the displacement y aIII (t) and the velocity v aIII (t) of the structure can be obtained by solving according to Equation (6):

[0041]

[0042] Coefficients Ca5 and C a6 can be obtained from the boundary conditions (y (tp) = y p , v (tp) = v p ):

[0043]

[0044] Substitute t a into Eqs. (13)-(14) to solve for the structural displacement y f and velocity v f at the end of the load application; for the fourth stage (t p to t a ), the structural displacement y aIV (t) and velocity v aIV (t) can be solved according to Eq. (6):

[0045]

[0046] v aIV (t) = -C a7 ω t sin(ω t t) + C a8 ω t cos(ω t t) (18)

[0047] where the coefficients C a7 and C a8 can be obtained from the boundary conditions (y (tf) = y f , v (tf) = v f ):

[0048]

[0049] When v aIV (t) is 0, the structure reaches the maximum deformation y max ;

[0050] As the liquid layer thickness increases, the constraint effect of the liquid medium on the structural deformation will stop before the end of the load application (mode 2), and at this time, t p < t w < t f ; the dynamic response process of the structure can also be divided into four stages:

[0051] The first stage is the elastic forced vibration of the cylindrical shell under liquid constraint;

[0052] The second stage is the plastic forced vibration of the cylindrical shell under liquid constraint;

[0053] The third stage is the plastic forced vibration of the cylindrical shell without liquid constraint;

[0054] The fourth stage is the plastic free vibration of the cylindrical shell without liquid constraint;

[0055] The theoretical model of this process can be described by formula (21);

[0056]

[0057] Similar to the solution process of formula (3), the deformation process of the structure in the four stages can be solved. Formulas (21) and (23) respectively summarize the deformation amount and deformation speed of the structure in different stages:

[0058]

[0059]

[0060] Among them, C b1 ~C b8 are coefficients, which are expressed by formula (24):

[0061]

[0062] Among them, ω tw is the plastic vibration frequency of the structure under liquid constraint, which can be expressed by the following formula:

[0063]

[0064] When v bIV (t) is 0, the structure reaches the maximum deformation amount y max ;

[0065] When the liquid layer thickness is large, the constraint effect of the liquid medium on the structure deformation will stop after the load action ends (mode 3). At this time, it satisfies t p <t f <t w ; The dynamic response process of the structure can be divided into four stages:

[0066] The first stage is the elastic forced vibration of the cylindrical shell under liquid constraint;

[0067] The second stage is the plastic forced vibration of the cylindrical shell under liquid constraint;

[0068] The third stage is the plastic free vibration of the cylindrical shell under liquid constraint;

[0069] The fourth stage is the plastic free vibration of the cylindrical shell without liquid constraint;

[0070] The deformation amount and deformation speed of the structure can be described by Formula (26) and Formula (27) respectively;

[0071]

[0072] where C c1 ~C c1 are coefficients, which are expressed by Equation (28):

[0073]

[0074] When v cIV (t) is 0, the structure reaches the maximum deformation amount y max .

[0075] The purpose of the present invention is to provide a pressure analysis system for an external liquid storage structure under the action of an explosion shock wave load, including:

[0076] A response theoretical model establishment module, which is used to establish a theoretical model of the structural dynamic response of an external liquid storage structure under the action of an explosion shock wave load;

[0077] A structural dynamic response determination module, which is used to regard the liquid storage container and the liquid medium as the additional mass mw of the structure, and determine the structural dynamic response process according to the liquid layer thickness and considering the restriction time of the liquid medium on the structural deformation;

[0078] A solution module, which is used to obtain the deformation situation of the external liquid storage structure under the action of an explosion shock wave load by solving the structural displacement solution.

[0079] Combined with the above technical solutions and solved technical problems, the advantages and positive effects of the technical solution to be protected by the present invention are:

[0080] First, according to the dynamic response process of the non-liquid storage structure, the present invention analyzes the dynamic response process of the external liquid storage structure under the action of an explosion shock wave load, conducts theoretical calculation and solution on its dynamic response process, and obtains the theoretical solutions of the displacement and deformation of the external liquid storage structure, greatly simplifying the calculation time.

[0081] For the pressure analysis method of the external liquid storage structure under the action of an explosion shock wave load, currently only the finite element model can be used for simulation, and the calculation process is often complex, the simulation process has a long cycle span and low efficiency. The present invention establishes a theoretical model of the structural dynamic response of the external liquid storage structure under the action of an explosion shock wave load, regards the liquid storage container and the liquid medium as the additional mass mw of the structure, determines the structural dynamic response process according to the liquid layer thickness and considering the restriction time of the liquid medium on the structural deformation, and obtains the deformation situation of the external liquid storage structure under the action of an explosion shock wave load by solving the structural displacement solution, greatly improving the solution efficiency and making up for the disadvantages of low solution efficiency and long time consumption of using finite element simulation.

[0082] By establishing a theoretical calculation model for the external liquid storage explosion-proof structure, the present invention greatly simplifies the complex finite element calculation process, thereby significantly improving the calculation efficiency. The traditional method has a long calculation cycle and consumes a large amount of resources, while the technical solution of the present invention significantly shortens the calculation time and reduces the occupation of computer resources, providing an efficient and practical solution for studying the dynamic response of the external liquid storage explosion-proof structure. This improvement makes the relevant structural design easier to optimize, providing a solid technical foundation for mass production and practical engineering applications.

[0083] The present invention first proposes a theoretical calculation model for the external liquid storage explosion-proof structure under the action of explosion shock waves and a calculation method for pressure and deformation, solving the problem in the current industry that relies on complex finite element simulations. The existing technical means cannot provide a simple and efficient calculation method, and the proposal of the present invention fills this technical gap, providing a new theoretical basis for the research on the anti-explosion performance of the external liquid storage structure. This innovative method not only promotes the development of theoretical research but also creates new possibilities for practical engineering applications.

[0084] By using the theoretical model of the present invention, the calculation efficiency is significantly improved, avoiding the cumbersome modeling and iteration processes in the traditional finite element method. The S-ALE algorithm is used to simulate the fluid-structure interaction, and key technologies such as ALE_STRUCTURED_FSI are used to control the calculation process, effectively reducing the high dependence on computer resources. This technology provides support for the wide application of the external liquid storage structure in anti-explosion performance analysis, shortening the R & D cycle, reducing costs, and at the same time improving the overall calculation accuracy and efficiency.

[0085] At present, the research on the dynamic response of the external liquid storage structure under explosion shock waves at home and abroad can only rely on traditional finite element simulations. The proposal of the present invention has completely changed this situation. By establishing a theoretical calculation model, it provides a scientific basis for the rapid prediction of pressure distribution and structural deformation, promoting the design, verification, and optimization of the external liquid storage explosion-proof structure. This breakthrough not only improves the research level in the industry but also lays a foundation for further innovation in the field of explosion-proof technology at home and abroad.

[0086] Second, aiming at the problem that the existing external liquid storage explosion-proof structure lacks an efficient pressure analysis method under the action of explosion shock wave loads, the present invention solves the complexity and high time-consuming problems of relying on traditional finite element simulation calculations by constructing a theoretical calculation model. The traditional method requires a large amount of computing resources and time, while the present invention significantly simplifies the calculation process by introducing a quantitative analysis of the additional mass and constraint action time of the liquid medium on the structure, achieving an efficient and accurate assessment of pressure distribution and dynamic response.

[0087] The calculation method proposed by the present invention regards the liquid medium as the additional mass of the structure, combines the constraint time of the liquid layer thickness on the structural deformation, and significantly improves the calculation efficiency. By analyzing the dynamic response process of the structure in stages through a theoretical model, it avoids the complex process of multiple iterations in traditional simulations. Under the same hardware conditions, while shortening the calculation cycle, it maintains high precision, providing an efficient analysis tool for engineering practice.

[0088] The present invention fills the technical gap in the field of pressure analysis of external liquid storage structures under explosion shock waves at home and abroad. By systematically establishing a dynamic response model, it clarifies the relationship among the liquid layer thickness, the explosion shock time, and the structural yield time, and proposes a phased analysis method for different constraint conditions. This innovation provides a theoretical basis for the subsequent optimization design and performance improvement of external liquid storage structures.

[0089] The technical solution of the present invention can be widely applied in fields such as explosion-proof facility design, industrial equipment safety assessment, and high-pressure storage tank protection. Through an efficient pressure analysis method, it reduces the design and verification costs of liquid storage structures, providing technical support for the mass production of explosion-proof structures. At the same time, the modular calculation method of the present invention is convenient for popularization and application, helping to improve the protection technology level and industrial competitiveness of related industries. Brief Description of the Drawings

[0090] Figure 1 is the flowchart of the pressure analysis method for an external liquid storage structure under explosion shock wave load provided by an embodiment of the present invention;

[0091] Figure 2 is the structural block diagram of the pressure analysis system for an external liquid storage structure under explosion shock wave load provided by an embodiment of the present invention;

[0092] Figure 3 is the comparison diagram of the simplified mean load and the actual load provided by an embodiment of the present invention;

[0093] Figure 4 is the schematic diagram of an explosion-proof structure based on an external liquid storage provided by an embodiment of the present invention;

[0094] Figure 5 is the effect diagram of the numerical simulation model and its calculation method of an external liquid storage explosion-proof structure for simulating fluid-structure interaction provided by an embodiment of the present invention. Detailed Description of the Invention

[0095] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0096] Embodiment 1: Industrial Storage Tank Explosion-Proof Design

[0097] In the design of large storage tanks in the chemical industry, the inside and outside of the storage tank may be threatened by explosion shock waves. Traditional designs usually increase the anti-explosion performance by increasing the thickness of the storage tank, which significantly increases the cost. The present invention analyzes the dynamic response of the external liquid storage structure of the storage tank under the action of explosion shock waves through a theoretical calculation model, and combines the optimization effect of the liquid layer thickness on the pressure distribution to provide a more economical and efficient solution. By applying the technical method of the present invention, a storage tank with an external liquid storage explosion-proof structure is designed, which not only reduces the material cost but also significantly improves the anti-explosion performance.

[0098] Example 2: Optimization of explosion protection for underground facilities

[0099] In the explosion-proof design of urban infrastructure such as subway tunnels or underground pipe galleries, explosion shock waves pose a major threat to the safety of the structure. The present invention adds an external liquid storage explosion-proof structure to the inner wall of the tunnel, and utilizes the absorption and buffering effects of the liquid medium on the shock wave to analyze the influence of different liquid layer thicknesses on the dynamic response of the tunnel structure through a theoretical calculation model, thus optimizing the design of the explosion-proof structure. Compared with the traditional thick-wall structure, the solution of the present invention significantly reduces the construction cost and at the same time improves the anti-explosion ability of underground facilities, providing an efficient guarantee for urban public safety.

[0100] As Figure 1 shown, a method for analyzing the pressure of an external liquid storage structure under the action of an explosion shock wave load provided by an embodiment of the present invention includes the following steps:

[0101] S101, establishing a theoretical model of the dynamic response of the structure of the external liquid storage structure under the action of an explosion shock wave load;

[0102] S102, regarding the liquid storage container and the liquid medium as the additional mass mw of the structure, and determining the dynamic response process of the structure according to the liquid layer thickness and considering the time of restriction of the liquid medium on the structural deformation;

[0103] S103, obtaining the deformation of the external liquid storage structure under the action of an explosion shock wave load by solving the structural displacement solution.

[0104] In the process of signal data processing, first, it is necessary to preprocess the response signals of the external liquid storage structure collected in experiments and simulations. This includes denoising the signals collected in experiments and effectively removing environmental noise using a high-frequency filter. Secondly, it is necessary to normalize the signals, adjusting the time and amplitude to the range required by the calculation model. For the simulation output data, the signals are divided into multiple stages according to the time step for stage-by-stage analysis. These preprocessing steps ensure the accuracy and availability of the input signal data.

[0105] According to the dynamic response model of the external liquid storage structure, the signal is decomposed into an elastic vibration stage, a plastic vibration stage, and a free vibration stage. The start and end times of each stage are determined by the end time of the liquid constraint effect, the start time of the structural plastic deformation, and the end time of the load action. In the elastic vibration stage, the signal characteristics reflect the elastic forced vibration state of the structure; in the plastic vibration stage, the signal describes the process of the gradually weakening restriction effect of the liquid constraint on the structure; in the free vibration stage, the signal mainly reflects the characteristics of the structural inertial response. The key signal data of each stage are used to calculate the structural displacement and velocity changes.

[0106] The phased signals are fitted through the theoretical model to verify the consistency between the signal change trend and the model. The key steps of model fitting include the quantitative analysis of the influence of the liquid layer thickness and the dynamic estimation of the structural dynamic response parameters. During the fitting process, the parameters of the elastic vibration and plastic vibration stages are determined, such as the vibration frequency and amplitude changes, and the constraint action time of the liquid layer thickness on the structural response is estimated. This analysis can reflect the dynamic change law of the signal characteristic parameters in different stages.

[0107] Based on the model fitting results, the variation laws of the maximum structural deformation and vibration frequency under different liquid layer thickness conditions are further analyzed. When the liquid constraint action time is short, the structure mainly undergoes elastic forced vibration and then turns into free vibration; while when the liquid layer is thick, the liquid constraint action runs through the plastic deformation stage and has a significant impact on the structural deformation. By statistically analyzing the maximum deformation and its corresponding vibration frequency changes under different liquid layer thicknesses, the main factors affecting the structural dynamic response are extracted, and a signal processing result report is generated using the optimized model to provide theoretical guidance.

[0108] In the embodiment of the present invention, the liquid storage container and the liquid medium are regarded as the additional mass mw of the structure. According to the liquid layer thickness and considering the constraint action time of the liquid medium on the structural deformation, the structural dynamic response process is determined:

[0109] For the external liquid storage structure under the action of an explosive shock wave, the following design can be carried out. The liquid medium and the liquid storage structure are regarded as the additional mass mw of the structure. When considering the constraint action of the liquid medium on the structural deformation, the equivalent mass ms needs to be corrected to the corrected equivalent mass mm:

[0110] m m =m e +m w =ρ s h s +ρ w h w +ρ p h p (1)

[0111] Among them, ρp is the density of the liquid medium, and hp is the liquid layer thickness; the restriction action time tw of the liquid medium can be obtained from the following formula:

[0112]

[0113] According to the analysis of the above formula, the restriction action time (tw) of the liquid medium is positively correlated with the liquid layer thickness (hp), indicating that the liquid layer thickness (hp) has a significant impact on the dynamic response process of the structure; therefore, it is necessary to conduct a classification discussion around the restriction action time (tw) of the liquid medium, the structure yield time (tp), and the impact load action end time (tf);

[0114] When the liquid layer thickness is relatively thin, the restriction action time of the liquid medium on the structural deformation is earlier than the occurrence of plastic deformation of the structure (Mode 1), that is, tw < tp < tf; in this case, the dynamic response process of the structure can be divided into four stages:

[0115] The first stage is the elastic forced vibration of the cylindrical shell under the restriction of the liquid;

[0116] The second stage is the elastic forced vibration of the cylindrical shell without liquid restriction;

[0117] The third stage is the plastic forced vibration of the cylindrical shell without liquid restriction;

[0118] The fourth stage is the plastic free vibration of the cylindrical shell without liquid restriction;

[0119] The theoretical model of this process can be described by formula (3);

[0120]

[0121] For the first stage (0 to tw), the displacement yaI(t) and velocity vaI(t) of the structure can be solved according to formula (6):

[0122]

[0123] Among them, ωyw is the elastic vibration frequency of the structure under the restriction of the liquid, which can be expressed by the following formula:

[0124]

[0125] The coefficients Ca1 and Ca2 can be obtained from the initial boundary conditions (y(0) = 0, v(0) = 0):

[0126]

[0127] Substituting \(t_w\) into Eqs. (4)-(5) can solve for the structural deformation \(y_w\) and velocity \(v_w\) at the moment when the liquid restraint effect disappears; for the second stage (\(t_w\) to \(t_p\)), the displacement \(y_{aII}(t)\) and velocity \(v_{aII}(t)\) of the structure can be solved according to Eq. (6):

[0128]

[0129] The coefficients \(C_{a3}\) and \(C_{a4}\) can be obtained from the boundary conditions (\(y(t_w)=y_w\), \(v(t_w)=v_w\)):

[0130]

[0131] Substituting \(y_p\) into Eqs. (9)-(10) can solve for the moment \(t_p\) when the structure begins to undergo plastic deformation and the velocity \(v_p\); for the third stage (\(t_p\) to \(t_f\)), the displacement \(y_{aIII}(t)\) and velocity \(v_{aIII}(t)\) of the structure can be solved according to Eq. (6):

[0132]

[0133] The coefficients \(C_{a5}\) and \(C_{a6}\) can be obtained from the boundary conditions (\(y(t_p)=y_p\), \(v(t_p)=v_p\)):

[0134]

[0135] Substituting \(t_a\) into Eqs. (13)-(14) to solve for the structural displacement \(y_f\) and velocity \(v_f\) at the end of the load application; for the fourth stage (\(t_p\) to \(t_a\)), the displacement \(y_{aIV}(t)\) and velocity \(v_{aIV}(t)\) of the structure can be solved according to Eq. (6):

[0136]

[0137] v aIV (t)= -C a7 ω t sin(ω t t)+C a8 ω t cos(ω t t) (18)

[0138] Among them, the coefficients \(C_{a7}\) and \(C_{a8}\) can be obtained from the boundary conditions (\(y(t_f)=y_f\), \(v(t_f)=v_f\)):

[0139]

[0140] When \(v_{aIV}(t)\) is 0, the structure reaches the maximum deformation \(y_{max}\);

[0141] As the liquid layer thickness increases, the constraint effect of the liquid medium on the structural deformation will stop before the end of the load application (Mode 2), and at this time, tp < tw < tf; the dynamic response process of the structure can also be divided into four stages:

[0142] The first stage is the elastic forced vibration of the cylindrical shell under the constraint of the liquid;

[0143] The second stage is the plastic forced vibration of the cylindrical shell under the constraint of the liquid;

[0144] The third stage is the plastic forced vibration of the cylindrical shell without the constraint of the liquid;

[0145] The fourth stage is the plastic free vibration of the cylindrical shell without the constraint of the liquid;

[0146] The theoretical model of this process can be described by Equation (21);

[0147]

[0148] Similar to the solution process of Equation (3), the deformation process of the structure in the four stages can be solved. Equation (21) and Equation (23) respectively summarize the deformation amount and deformation speed of the structure in different stages:

[0149]

[0150] Among them, Cb1 to Cb8 are coefficients, which are expressed by Equation (24):

[0151]

[0152] Among them, ωtw is the plastic vibration frequency of the structure under the constraint of the liquid, which can be expressed by the following formula:

[0153]

[0154] When vbIV(t) is 0, the structure reaches the maximum deformation amount ymax;

[0155] When the liquid layer thickness is relatively large, the constraint effect of the liquid medium on the structural deformation will stop after the end of the load application (Mode 3), and at this time, tp < tf < tw; the dynamic response process of the structure can be divided into four stages:

[0156] The first stage is the elastic forced vibration of the cylindrical shell under the constraint of the liquid;

[0157] The second stage is the plastic forced vibration of the cylindrical shell under the constraint of the liquid;

[0158] The third stage is the plastic free vibration of the cylindrical shell under the constraint of the liquid;

[0159] The fourth stage is the plastic free vibration of a cylindrical shell without liquid constraints;

[0160] The deformation amount and deformation speed of the structure can be described by formulas (26) and (27) respectively;

[0161]

[0162] Among them, Cc1 to Cc1 are coefficients, represented by equation (28):

[0163]

[0164] When vcIV(t) is 0, the structure reaches the maximum deformation amount ymax.

[0165] As Figure 2 shown, a pressure analysis system for an external liquid storage structure under the action of an explosion shock wave load provided by an embodiment of the present invention includes:

[0166] A response theoretical model establishment module, used to establish a theoretical model of the structural dynamic response of the external liquid storage structure under the action of an explosion shock wave load;

[0167] A structural dynamic response determination module, used to regard the liquid storage container and the liquid medium as the additional mass mw of the structure, and determine the structural dynamic response process according to the liquid layer thickness and considering the time of the restrictive effect of the liquid medium on the structural deformation;

[0168] A solution module, used to obtain the deformation situation of the external liquid storage structure under the action of an explosion shock wave load by solving the structural displacement solution.

[0169] Another object of the present invention is to provide a computer device, the computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the pressure analysis method for the external liquid storage structure under the action of an explosion shock wave load.

[0170] Another object of the present invention is to provide a computer-readable storage medium, storing a computer program, and when the computer program is executed by a processor, the processor executes the steps of the pressure analysis method for the external liquid storage structure under the action of an explosion shock wave load.

[0171] Another object of the present invention is to provide an information data processing terminal, and the information data processing terminal is used to implement the pressure analysis system for the external liquid storage structure under the action of an explosion shock wave load.

[0172] Specific implementation of the present invention:

[0173] A 1 / 4 axisymmetric numerical calculation model was established using ANSYS LS-DYNA for numerical simulation verification. Among them, the TNT, air, and water media were simulated using the Structured ALE method, and the cylindrical shell, liquid storage container, and spherical fragments were simulated using the Lagrangian structure. In Structured ALE, the YZ plane and the XZ plane were set as symmetric boundaries, and the remaining planes were fluid outflow boundaries. In the Lagrangian structure, displacement constraints in the X direction and rotational constraints in the Y and Z directions were applied to the grid nodes on the YZ plane, and displacement constraints in the Y direction and rotational constraints in the X and Z directions were applied to the grid nodes on the XZ plane. The fluid-structure interaction was simulated by the S-ALE algorithm, and the calculation process was controlled using the keyword ALE_STRUCTURED_FSI to effectively avoid fluid medium leakage.

[0174] The finite element mesh size of the cylindrical shell and the liquid storage container was 2 mm, and the MAT_PLASTIC_KINEMATIC model (a kinematic hardening plasticity model) was used to describe the steel material of the cylindrical shell. Calculations were carried out by setting the mesh size of Structured ALE to 1 mm, 2 mm, 4 mm, and 6 mm, and it was found that the numerical model with a 2-mm mesh size could better reflect the propagation process of the initial explosion shock wave and the reflected shock wave. Taking the peak value of the reflected pressure as an example, the deviation between the numerical simulation results and the experimental results was within 10%, so 2 mm was finally selected as the mesh size of Structured ALE.

[0175] Based on the existing numerical model, the equivalent load was obtained using the load homogenization method. The simplified uniform load Pser at different sampling distances was applied to the inner surface of the cylindrical shell structure in the form of a uniformly distributed load, and the radial deformation of the structure was measured. As Figure 3 shown, the radial deformation process of the structure under the action of the simplified uniform load was compared and contrasted with the actual radial deformation process of the structure (Model S). It can be seen that as the sampling distance increased, the radial deformation of the structure continuously decreased. When the sampling distance was small, the deformation of the structure under the simplified uniform load was greater than the actual situation, and vice versa when the sampling distance was large. Generally speaking, when the sampling distance was 100, the deformation of the structure under the simplified uniform load was in good agreement with the actual situation: when L = 100, the maximum deformation of the structure under the simplified uniform load (13.7 mm) was about 2.2% higher than the actual maximum deformation (13.4 mm). Pser (L = 100) was selected as the target protection load, and its peak value and action time were 0.1774 GPa and 0.0665 ms, respectively.

[0176] An external liquid storage explosion-proof structure was designed according to the theoretical calculation model, as Figure 4As shown in the figure. Compared with the traditional iron plate explosion-proof structure, the external liquid storage explosion-proof structure greatly reduces the material cost, provides better explosion resistance performance, and is convenient for modular production and use.

[0177] As Figure 5 shown, a finite element simulation was carried out on the external liquid storage structure. A 1 / 4 axisymmetric numerical calculation model was established using ANSYS LS-DYNA for numerical simulation verification. Among them, the TNT, air and water media were simulated using the Structured ALE method, and the cylindrical shell, liquid storage container and spherical fragments were simulated using the Lagrangian structure. In Structured ALE, the YZ plane and the XZ plane were set as symmetric boundaries, and the other planes were fluid outflow boundaries. In the Lagrangian structure, the grid nodes on the YZ plane were subjected to displacement constraints in the X direction and rotational constraints in the Y and Z directions, and the grid nodes on the XZ plane were subjected to displacement constraints in the Y direction and rotational constraints in the X and Z directions. The fluid-structure interaction was simulated by the S-ALE algorithm, and the calculation process was controlled by the keyword ALE_STRUCTURED_FSI to effectively avoid the leakage of fluid media.

[0178] The finite element mesh size of the cylindrical shell and the liquid storage container was 2 mm, and the kinematic hardening plasticity model (MAT_PLASTIC_KINEMATIC) was used to describe the steel material used for the cylindrical shell. By setting the mesh sizes of Structured ALE to 1 mm, 2 mm, 4 mm and 6 mm for calculation, it was found that the numerical model with a mesh size of 2 mm could better reflect the propagation process of the initial explosion shock wave and the reflected shock wave. Taking the peak value of the reflected pressure as an example, the finite element model calculation was compared with the theoretical calculation results. As shown in the figure below, the deviation between the numerical simulation results and the theoretical calculation results was within 10%.

[0179] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated designed hardware. Those of ordinary skill in the art can understand that the above devices and methods can be implemented using computer-executable instructions and / or included in processor control code, for example, such code is provided on a carrier medium such as a disk, CD, or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and their modules of the present invention can be implemented by hardware circuits of programmable hardware devices such as very large scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, or can be implemented by a combination of the above hardware circuits and software such as firmware.

[0180] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be covered by the protection scope of the present invention.

Claims

1. A method for analyzing the pressure of an external liquid storage structure under the action of an explosion shock wave load, characterized in that: The method comprises the following steps: Establish a theoretical model of the structural dynamic response of the external liquid storage structure under the impact of explosion shock wave load; The liquid storage container and the liquid medium are regarded as the additional mass of the structure. According to the thickness of the liquid layer and the time of the liquid medium's restriction on the structural deformation, the dynamic response process of the structure is determined. By solving the displacement solution of the structure, the deformation of the external liquid storage structure under the action of the explosion shock wave load is obtained.

2. The pressure analysis method according to claim 1, characterized in that: The additional mass of the structure is corrected according to the density of the liquid medium and the thickness of the liquid layer. By analyzing the constraint action time of the liquid medium on the structural deformation, the relationship between the constraint action time and the structural yield time and the impact load action time is determined.

3. The pressure analysis method according to claim 1, characterized in that: When the liquid layer is thin, the constraint time of the liquid medium is shorter than the time for the structure to undergo plastic deformation. The dynamic response of the structure is divided into four stages: elastic vibration stage, elastic vibration stage without liquid constraint, plastic vibration stage without liquid constraint, and free vibration stage.

4. The pressure analysis method according to claim 1, characterized in that: When the thickness of the liquid layer increases to a certain extent, the constraint time of the liquid medium covers the plastic deformation stage of the structure but is earlier than the end time of the impact load. The dynamic response of the structure is divided into four stages: elastic vibration stage under liquid constraint, plastic vibration stage under liquid constraint, plastic vibration stage without liquid constraint, and free vibration stage.

5. The pressure analysis method according to claim 1, characterized in that: When the thickness of the liquid layer increases further, the constraint time of the liquid medium continues until the impact load ends, and the dynamic response of the structure is divided into four stages: elastic vibration stage under liquid constraint, plastic vibration stage under liquid constraint, plastic free vibration stage under liquid constraint and plastic free vibration stage without liquid constraint.

6. The pressure analysis method according to claim 1, characterized in that: The deformation and speed changes at each stage are calculated and the maximum deformation is analyzed to evaluate the influence of different liquid layer thicknesses on the explosion-proof performance of the external liquid storage structure.

7. A pressure analysis system for an external liquid storage structure under an explosion shock wave load, characterized in that: include: Model building module: used to construct a theoretical model of the structural dynamic response of the external liquid storage structure under the action of explosion shock wave load; Parameter calculation module: used to regard the liquid storage container and liquid medium as the additional mass of the structure, calculate the constraint action time based on the liquid medium density and liquid layer thickness, and correct the equivalent mass; Response analysis module: used to determine the dynamic response process of the structure and obtain the deformation of the structure by calculating the displacement and velocity solutions; Result output module: used to output analysis results such as pressure distribution, structural deformation and velocity change.

8. The pressure analysis system according to claim 1, characterized in that: The parameter calculation module comprises: Additional mass correction unit: calculates the corrected additional mass of the structure according to the density of the liquid medium and the thickness of the liquid layer; Constraint time calculation unit: used to calculate the constraint action time of the liquid medium, and divide the response mode according to the relationship between this time and the structural yield time and the impact load action time.

9. The pressure analysis system according to claim 1, characterized in that: The response analysis module includes: Stage division unit: used to divide the different stages of structural dynamic response according to the liquid constraint action time, including elastic vibration stage, plastic vibration stage and free vibration stage; Dynamic solution unit: used to calculate the deformation and speed change in each stage, and analyze the maximum deformation.

10. The pressure analysis system according to claim 1, characterized in that: The result output module includes: Pressure distribution output unit: used to generate pressure distribution diagram of liquid storage structure under the action of explosion shock wave load; Deformation analysis unit: used to output the structural deformation and dynamic response characteristics under different liquid layer thickness conditions to evaluate the explosion resistance of the liquid storage structure.

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