Calculation method for accurately predicting deformation of cylindrical explosion container

Abstract

The invention discloses a calculation method for accurately predicting deformation of a cylindrical explosion vessel, which comprises the following steps of: firstly, aiming at a cylindrical thin shell structure, establishing a radial dynamic balance equation for describing the dynamic response of the cylindrical thin shell structure, obtaining a reflection pressure load model based on a simplified finite element model, and proposing a linear strengthening rigid-plastic hypothesis of a cylindrical shell material; solving the length of the deformation area by using an energy method; after displacement and bending moment boundary conditions are substituted, a theoretical calculation method capable of quantitatively predicting time domain and space domain deformation of the cylindrical explosion container is established; according to the method, a computable parameter system is provided for the design of the explosion container, a theoretical predicted value is well matched with a test result, and the theoretical blank of a traditional empirical formula under a near-field explosion working condition is filled.

Description

Technical field:

[0001] The present invention relates to the technical field of explosion protection, and in particular to a calculation method for accurately predicting the deformation of a cylindrical explosion container. Background technology:

[0002] As a protective device that effectively confines explosive energy and detonation products, explosion containers have gained widespread application in a variety of key fields, including urban emergency response, industrial production, laboratory research, and aerospace, due to their significant advantages, including wide protection range, low manufacturing cost, and easy maintenance. In particular, in scenarios such as emergency response, hazardous materials transportation, and safety protection, explosion containers can significantly reduce the impact of explosions on the surrounding environment and personnel, thereby improving overall safety. Cylindrical explosion-proof structures, due to their portability, simple manufacturing process, low cost, and high reliability, have been widely used in fields such as protection against low-yield explosives and transportation of pyrotechnics. For example, Patent 202411217882 discloses a cylindrical explosion-proof canister, while Patent 2018100556932 proposes a miniature explosion-proof canister suitable for detonators. These technical solutions have demonstrated excellent protection effectiveness and engineering applicability in practical applications.

[0003] Currently, the design of explosion containment vessels mostly relies on a test-and-verify approach. This involves designing and fabricating a variety of potentially advantageous structures, then conducting multiple explosion tests and testing to determine the explosion protection capabilities and safety redundancy of each structure. However, due to limitations in test sites, staffing, and safety requirements, explosion testing struggles to efficiently and systematically support the demands of structural design and optimization. Furthermore, explosion tests take days, computer numerical simulations take hours, and theoretical model predictions take only seconds. Therefore, theoretical models are playing an increasingly important role in the design and improvement of new explosion containment vessels.

[0004] Existing theoretical analysis methods primarily focus on the elastic vibration and small plastic deformation (<1%) of metal shells under impact loads. However, they still have significant limitations in quantitatively calculating the large plastic deformation (>1%) of cylindrical structures. Furthermore, most existing calculation methods fail to consider the actual loading time of the internal blast load and estimate the shell's initial velocity based solely on the impulse theorem. In reality, the internal blast load typically lasts for tens of microseconds, while the shell's deformation process lasts for hundreds of microseconds. Simply ignoring the loading time inevitably leads to discrepancies between the calculated results and the actual situation. These limitations of existing theoretical analysis methods have, to a certain extent, constrained the structural optimization and engineering application of explosive containers. Therefore, it is urgent to develop a calculation method that can accurately predict the large deformation behavior of cylindrical explosive containers, fully considering the dynamic loading characteristics of the blast load, and providing a solid theoretical foundation and technical support for the structural design and performance improvement of new explosive containers. Summary of the invention:

[0005] In view of this, the present invention provides a calculation method for accurately predicting the deformation of a cylindrical explosion container, which can accurately predict the deformation of a cylindrical explosion container during an explosion.

[0006] The technical solutions for implementing the present invention are as follows:

[0007] A calculation method for accurately predicting the deformation of a cylindrical explosion container comprises the following steps:

[0008] S1. Construct radial dynamic equilibrium equations for thin-walled cylindrical explosion container structures;

[0009] S2. Approximately characterize the spatiotemporal distribution P(x, t) of the reflected overpressure acting on the inner wall surface of the explosion container shell;

[0010] S3. Based on the consistency of the dynamic displacement response of the explosion container shell and the excitation pressure pulse in spatial distribution, the time domain and spatial domain distribution law of the radial displacement field of the explosion container shell is obtained. ρ (x,t);

[0011] S4. A linear enhanced rigid-plastic model is used to characterize the yield stress-plastic strain relationship of the explosion container shell;

[0012] S5. Calculate the length of the plastic deformation area of ​​the explosion container shell using the energy method;

[0013] S6, the time-space distribution of the reflected overpressure P of S2, the time-domain and space-domain distribution law of S3, the relationship between the yield stress and plastic strain of S4, and the length of the plastic deformation area of ​​S5 are substituted into the radial dynamic equilibrium equation of S1 to obtain the radial displacement time history curve u0(t) at the center of the inner wall of the explosion container shell. According to u0(t), the radial displacement field u ρ Numerical solution for (x,t).

[0014] Furthermore, the radial dynamic balance equation is:

[0015]

[0016] The radial dynamic balance equation is constructed in a cylindrical coordinate system with coordinate variables being radial ρ, circumferential θ and axial x; q ρ is the radial component of the external load, t is the time of the structural deformation process, and the moment when the pressure load begins to act on the explosion container shell is the zero point; u ρ is the radial displacement of the mid-plane of the explosion container shell; ρ, h, R and l0 represent the density, thickness, inner diameter and length of the explosion container shell respectively; N θ , Q x and Q θ They represent the hoop membrane force, axial shear force and hoop shear force per unit length of the mid-surface, respectively.

[0017] Furthermore, the spatiotemporal distribution of reflected overpressure P(x,t) is:

[0018]

[0019] Wherein, P0 is the peak overpressure of the pressure pulse at the center of the inner wall of the explosion container shell 1 (x=0), a is the arrival time of the shock wave overpressure peak, and τ is the characteristic time constant describing the shock wave overpressure decay.

[0020] Further, Where l1 is the length of the plastic deformation region, and u0(t) is the radial displacement time history curve at x=0.

[0021] Furthermore, the yield stress-plastic strain relationship of the explosion container shell is:

[0022]

[0023] Among them, σ y and σ0 are the flow stress and initial yield stress of the explosion container shell respectively; E p is the plastic hardening modulus, is the effective plastic strain.

[0024] Furthermore, the effective plastic strain Expressed as:

[0025]

[0026] Among them, ε θ , ε ρ and ε x denote hoop strain, radial strain and axial strain respectively, γ xρ Represents the shear strain between the axial and radial directions.

[0027] Furthermore, the length l1 of the plastic deformation area of ​​the explosion container shell is:

[0028]

[0029] in

[0030]

[0031] P0 is the peak overpressure of the pressure pulse at the center of the inner wall of the explosion container shell (x=0).

[0032] Furthermore, the radial displacement time history curve u0(t) at the center of the inner wall is:

[0033]

[0034] in,

[0035]

[0036] Beneficial effects:

[0037] 1. The input of the reflected pressure load model in the present invention is derived from a simplified finite element model rather than directly using a commonly used empirical formula, thereby avoiding the order of magnitude error that may be caused by the empirical formula in the case of near-field explosion.

[0038] 2. The explosive loading process of the present invention is divided into a rising stage and a decaying stage, which fully considers the action time of the explosion pressure and the container shell.

[0039] 3. The linear enhanced rigid-plastic hypothesis proposed in this invention can effectively reflect the strain hardening effect of metal materials, breaking through the technical bottleneck that traditional vibration theory is only applicable to small deformation analysis. It can provide direct guidance for the selection of metal materials for the main body of the explosion container and avoid material waste caused by overly conservative design.

[0040] 4. The method of the present invention provides a calculable parameter system for explosion vessel design. Its theoretical prediction values ​​are in good agreement with the experimental results, filling the theoretical gap of traditional empirical formulas under near-field explosion conditions. Description of the drawings:

[0041] Figure 1 The present invention is a flow chart of a calculation method for accurately predicting the deformation of a cylindrical explosion container.

[0042] Figure 2 Schematic diagram of the dynamic response of the explosion container shell under the implosion load in the present invention.

[0043] Figure 3 This is a simplified structural diagram of Example 1 of the present invention.

[0044] Figure 4 This is a comparison chart of the time domain distribution law predicted theoretically in the present invention and the experimental measurement results.

[0045] Figure 5 This is a comparison chart of the spatial distribution law predicted theoretically in the present invention and the experimental measurement results.

[0046] Wherein: 1-explosion vessel shell, 1.1-plastic deformation area, 1.2-undeformed area, 1.3-AA circumferential section, 1.4-axial section, 2-explosive. Specific implementation method:

[0047] The present invention proposes a calculation method that can accurately predict the deformation of cylindrical explosion containers. First, for the cylindrical thin shell structure, a radial dynamic equilibrium equation describing its dynamic response is established, and based on the simplified finite element model, a reflected pressure load model is obtained. The linear reinforced rigid-plastic hypothesis of the cylindrical shell material is proposed, and the energy method is used to solve the length of the deformation area. After substituting the displacement and bending moment boundary conditions, a theoretical calculation method is established that can quantitatively predict the time domain and space domain deformation of the cylindrical explosion container. The specific steps of the calculation method are as follows: Figure 1 shown.

[0048] 1. Radial dynamic balance equation

[0049] The explosion container shell 1 is a simplified cylindrical explosion container. It is assumed that the container body is a thin-walled cylindrical shell (thickness / inner radius <5%), such as Figure 2 As shown. In the cylindrical coordinate systems of radial (ρ), circumferential (θ) and axial (x), the radial dynamic equilibrium equations controlling the deformation region 1.1 are:

[0050]

[0051] in

[0052]

[0053] Where q ρ is the radial component of the external load, in this case the implosion load P generated by the explosive 2. t is the time of the structural deformation process, with the moment when the pressure load begins to act on the explosion container shell 1 as the zero point. u ρ is the radial displacement of the mid-plane of the explosion container shell 1. ρ, h, R and l0 represent the density, thickness, inner diameter and length of the explosion container shell 1 respectively. N θ , Q x and Q θ Respectively represent the hoop membrane force, axial shear force and hoop shear force per unit length of the mid-plane. x 、M θ and M xθ They represent the axial and hoop in-plane bending moments, and mid-plane torque per unit length, respectively.

[0054] The circumferential symmetry of the explosion container shell 1 and the explosive 2 results in the distribution of the internal force and bending moment in the mid-plane being independent of θ. Therefore, equations (1) and (2) can be simplified to:

[0055]

[0056] in

[0057]

[0058] N θ=σ y h (5)

[0059] Where P, N θ , Q x , M x , and u ρ are functions with x and t as independent variables. y is the flow yield stress of the explosion container shell 1. Figure 2 As shown, the explosion pressure P generated by explosive 2 acts on both the plastic deformation area 1.1 and the undeformed area 1.2, and is the only external load. The calculation range of x in the formula is [0, l1], that is, only the time domain and spatial domain deformation distribution of the plastic deformation area 1.1 is calculated. The undeformed area 1.2 only undergoes elastic deformation or no deformation and is not within the calculation range of the above formula. The AA circumferential section 1.3 shows the annular membrane force N generated by the annular expansion under the action of the explosion pressure P. θ , the resultant force direction points to the center of the circle, hindering the deformation of the explosion container shell 1. The axial section 1.4 shows the axial shear force Q caused by the uneven axial deformation under the action of the explosion pressure P. x , and its direction also points to the center of the circle, hindering the deformation of the explosion container shell 1.

[0060] 2. Reflected pressure load model

[0061] Near field explosion (proportional distance less than 0.5kg / m 1 / 3 ), commonly used empirical formulas will produce large errors, even orders of magnitude differences from the true value. Therefore, the present invention preferably uses the pressure-time history curve obtained in the numerical simulation as the load input for the theoretical model. Numerical simulation can be performed using finite element software such as LS-DYNA, ABAQUS, or AUTODYN. Only the reflected pressure P0 acting on the center of the inner wall (x=0) of the explosion container shell 1 after the explosion of the explosive 2 is calculated, without the need for subsequent deformation calculations. The general form of the reflected overpressure P acting on the inner wall surface of the explosion container shell 1 can be described as follows:

[0062]

[0063] Where P0 is the peak overpressure of the pressure pulse at the center of the inner wall of the explosion container shell 1 (x = 0), and its specific value is calculated using a simplified finite element model. The spatial distribution of the pressure pulse is described by the shape function f(x), which is expressed as:

[0064]

[0065] Where 2l0 is the total length of the explosion container shell 1.

[0066] Since the explosion container shell 1 and the explosive 2 have circumferential symmetry, the distribution function g(θ) of the pressure pulse in the circumferential direction (θ direction) is 1, that is:

[0067] g(θ)=1 (8)

[0068] The temporal distribution of the pressure pulse is given by the shape function Description, its expression is in the form of piecewise function:

[0069]

[0070] Where a is the arrival time of the shock wave overpressure peak, and τ is the characteristic time constant describing the shock wave overpressure decay.

[0071] The spatiotemporal distribution of the reflected overpressure P acting on the inner wall surface of the explosion container shell 1 can be approximately expressed as:

[0072]

[0073] 3. Spatial distribution model of radial displacement field

[0074] Considering that the explosive 2 is the only external load on the explosion container shell 1, according to the principle of structural dynamics similarity, the dynamic displacement response of the explosion container shell 1 is consistent with the excitation pressure pulse in spatial distribution. Based on this, the radial displacement field u ρ The spatial distribution of (x, t) can be expressed as follows:

[0075]

[0076] Where l1 is the length of the plastic deformation zone 1.1 and u0(t) is the radial displacement time history curve at x=0.

[0077] 4. Linear hardening rigid-plastic model

[0078] The explosion container shell 1, which serves as the load-bearing structure, is preferably made of steel with good ductility, such as Q235, Q345, or 316L. These materials exhibit significant strain hardening properties, with their plastic yield stress increasing continuously with increasing plastic strain. To accurately describe the mechanical response of thin-shell structures under explosive loads, the present invention innovatively employs a linear reinforced rigid-plastic model to characterize the shell's stress-strain relationship. The model is specifically formulated as follows:

[0079]

[0080] Where σ y and σ0 are the flow stress and initial yield stress of the explosion container shell 1 respectively. E p is the plastic hardening modulus. is the effective plastic strain.

[0081] The linear hardened rigid-plastic model primarily studies the mechanical response characteristics of thin shell structures under uniaxial yield loading. Based on the model's assumptions, the influence of the elastic segment is ignored in subsequent analyses, and the distinction between plastic strain and total strain is no longer made. In a cylindrical coordinate system, the effective plastic strain can be expressed as follows:

[0082]

[0083] in

[0084]

[0085] Where ε θ , ε ρ and ε x denote hoop strain, radial strain and axial strain respectively, γ xρ Indicates the shear strain between the axial and radial directions. u ρ and w are radial displacement and axial displacement respectively. Since the structure is axially symmetrical, the circumferential displacement u θ and shear strain γ ρθ and γ xθ In the explosion container shell 1, the axial displacement w is much smaller than the radial displacement u ρ To simplify the theoretical model, the axial displacement w is neglected.

[0086] The explosion container shell 1 follows the plastic deformation isovolumetric law during the impact deformation process, and the variation of its thickness h during the expansion process satisfies the following relationship:

[0087] 2πRh0dx=2π(R+u ρ (x,t))h1dx (15)

[0088] Where h0 is the initial thickness of the explosion container shell 1 before deformation, h1 is the shell thickness during the explosive loading process, and dx is the axial unit length. The shell thickness h1 under explosive loading can be expressed as follows:

[0089]

[0090] Therefore, the plastic strain component in formula (13) can be specifically expressed as:

[0091]

[0092] Due to the radial displacement u ρ The magnitude of is much smaller than the shell radius R, so u is ignored in formula (18) ρThe deformation of the shell is mainly concentrated near the center area (x=0), at which time sin(πx / l1) approaches 0, cos(πx / 2l1) approaches 1, and the shear strain γ xρ Much smaller than the hoop strain ε θ .

[0093] Therefore, the effective plastic strain in formula (13) can be expressed as:

[0094]

[0095] 5. Energy method to solve the deformation area length

[0096] Assuming that the plastic deformation of the explosion container shell 1 is completely caused by the explosion impact load acting there, the energy method can be used to obtain:

[0097] dE=dW (22)

[0098] Where dE and dW are the kinetic energy and strain energy per unit length in the axial direction, respectively.

[0099] The area per unit length dS and mass dM can be expressed as:

[0100] dS=2πRdx (23)

[0101] dM=ρhdS (24)

[0102] At the same time, the normal impulse I of the explosion impulse I(x) n (x) can be expressed as:

[0103] I n (x)=I(x)cos 2 φ (25)

[0104] in

[0105]

[0106] Here, only the impulse of the exponential decay part of the shock wave pressure is considered. represents the incident angle of the explosion shock wave at x. The kinetic energy and strain energy per unit axial length can be specifically expressed as:

[0107]

[0108] in

[0109]

[0110] In the formula [ε p ] represents the maximum equivalent plastic strain that can be ignored under the linear rigid-plastic model. Specifically, the equivalent plastic strain is less than [ε p] is considered as the undeformed area, and x=l1 is the critical point of deformation. θ ](1% is acceptable) and [u ρ ] are [ε p ]’s hoop strain and radial displacement.

[0111] Therefore, the length l1 of the plastic deformation area 1.1 of the explosion container shell 1 can be calculated by the following formula:

[0112]

[0113] in

[0114]

[0115] 6. Boundary conditions and time domain distribution model of radial displacement field

[0116] Based on the spatiotemporal distribution model of the internal explosion load (Equation (10)), the linear enhanced rigid-plastic constitutive relations (Equations (12) and (21)), and the spatial distribution law of the displacement field (Equation (11)), the radial dynamic equilibrium equation (Equation (3)) of the explosion container shell 1 can be specifically written as:

[0117]

[0118] in

[0119]

[0120] Where u0(t) and are the radial displacement and normalized peak overpressure at x = 0, respectively.

[0121] Considering that the explosion container shell 1 and the explosive 2 are symmetrical about the x=0 plane, the shear force Q in this plane is x (x,t) can be expressed as:

[0122]

[0123] The explosion container shell 1 forms annular plastic hinges at x = 0 and x = l1. Therefore, the bending moment M x The boundary conditions at (x,t) can be described as:

[0124] M x (0,t)=-M0, M x (l1,t)=M0 (36)

[0125] Where M0=(σh 2 ) / 4 is the critical bending moment of the explosion container shell 1 when it reaches the plastic flow stage under the action of pure bending moment.

[0126] According to the above boundary conditions of shear force and bending moment, excluding M x The dynamic equilibrium equation of the term can be described as:

[0127]

[0128] in

[0129]

[0130] And have the following initial conditions of displacement and velocity:

[0131]

[0132] From this we can get:

[0133]

[0134] The above formula describes the time domain distribution law of the displacement of the plastic deformation area 1.1 at x = 0, and its corresponding spatial domain distribution law is given by formula (11).

[0135] Example 1:

[0136] The present invention provides an embodiment of a cylindrical explosion container with a protection equivalent of 100g TNT. Based on the theoretical analysis method described above, the temporal and spatial deformation patterns of the plastic deformation region 1.1 of the explosion container shell 1 under the action of explosive 2 were predicted. This prediction was compared with explosion test results to verify the accuracy of the calculation method for predicting cylindrical explosion container deformation. The loading conditions, specimen geometry, and material parameters of the theoretical model were consistent with those of the experiments. The input parameters are shown in Table 1.

[0137] like Figure 3 As shown, the cylindrical explosion container comprises two parts: an explosion container shell 1 and an explosive 2. The explosion container shell 1 is welded from a ductile metal such as Q235, Q345, or 304 stainless steel. The explosive 2 is determined based on actual usage and is generally made of black powder, TNT, etc. During calculation, it is necessary to uniformly convert the explosive heat ratio into TNT equivalent.

[0138] A simplified numerical model of a cylindrical explosion container was established using ANSYS / LS-DYNA finite element software. The peak overpressure P0, linear growth coefficient a, and exponential decay coefficient τ acting on the inner wall of the explosion container shell 1 were calculated under different explosive equivalent loads. Taking 100g of TNT as an example, its reflected peak overpressure P0 is 228.76MPa, the linear growth coefficient a is 3.94μs, and the exponential decay coefficient is 13.8μs. Substituting into Equation (10), the reflected pressure load model of 100g of TNT is obtained as follows:

[0139]

[0140] Structural parameters of the explosion container shell 1, such as density (ρ s ), yield stress (σ), thickness (h), plastic hardening modulus (E p ), inner diameter (R) and axial length (l0) are shown in Table 1:

[0141] Table 1 Parameters input in the theoretical calculation method

[0142]

[0143] Substituting into equation (11), we can get the radial displacement field u ρ Spatial distribution of (x,t):

[0144]

[0145] Where l1 is the length of the plastic deformation zone 1.1. When the calculation accuracy is high, the value of l1 is accurately calculated by equations (22) to (32). In general, the following formula can be used for quick estimation:

[0146]

[0147] The calculated length l1 of the plastic deformation zone 1.1 is 0.087m.

[0148] Substituting the above calculation results into equations (37) and (38), the dynamic equilibrium equation of the explosion container shell 1 can be obtained:

[0149]

[0150] in

[0151]

[0152] By numerically solving the above differential equations, we can obtain the temporal and spatial distribution laws of the deformation of the explosion container shell 1 under the internal explosion load:

[0153]

[0154] The units in the above formula are the international units of m-kg-s.

[0155] Figure 4 The time-domain distribution model of the radial displacement field in Equation (46) is shown, representing the deformation of the explosion container shell 1 at the same location at different times. Compared with the experimental results, the overall trends are consistent. The theoretical model predicts a peak deformation of 11.82 mm, which differs by 7.36% from the experimental measurement of 11.01 mm. Because the theoretical model does not consider the elasticity of the material, it can only relatively accurately predict the peak deformation but cannot calculate the final deformation.

[0156] Figure 5 The spatial distribution model of the radial displacement field in Equation (47) is shown, that is, the deformation field distribution at different locations of the explosion container shell 1 at the same time. After comparison with the experimental measurement results, it was found that the peak deformation prediction errors of the theoretical model at 80μs and 140μs were -3.9% and 2.5%, respectively, showing good consistency between the theoretical calculation results and the experimental results.

[0157] In summary, the calculation results of the explosion vessel deformation proposed in this invention are in good agreement with the experimental results, realizing the quantitative characterization of the impact deformation of the internal explosion load, providing a calculable parameter system for the design of cylindrical explosion vessels, and improving the deformation prediction accuracy of the theoretical model under near-field explosion conditions. This is of great significance for guiding the engineering application of cylindrical explosion vessels.

Claims

1. A calculation method for accurately predicting the deformation of cylindrical explosion containers, characterized in that: The following steps are involved: S1. Construct radial dynamic equilibrium equations for thin-walled cylindrical explosion container structures; S2. Approximately characterize the spatiotemporal distribution P(x, t) of the reflected overpressure acting on the inner wall surface of the explosion container shell; S3. Based on the consistency of the dynamic displacement response of the explosion container shell and the excitation pressure pulse in spatial distribution, the time domain and spatial domain distribution law of the radial displacement field of the explosion container shell is obtained. ρ (x,t); S4. A linear enhanced rigid-plastic model is used to characterize the yield stress-plastic strain relationship of the explosion container shell; S5. Calculate the length of the plastic deformation area of ​​the explosion container shell using the energy method; S6, the time-space distribution of the reflected overpressure P of S2, the time-domain and space-domain distribution law of S3, the relationship between the yield stress and plastic strain of S4, and the length of the plastic deformation area of ​​S5 are substituted into the radial dynamic equilibrium equation of S1 to obtain the radial displacement time history curve u0(t) at the center of the inner wall of the explosion container shell. According to u0(t), the radial displacement field u ρ Numerical solution for (x,t).

2. The calculation method for accurately predicting the deformation of a cylindrical explosion container according to claim 1, characterized in that: The radial dynamic balance equation is: The radial dynamic balance equation is constructed in a cylindrical coordinate system with coordinate variables being radial ρ, circumferential θ and axial x; q ρ is the radial component of the external load, t is the time of the structural deformation process, and the moment when the pressure load begins to act on the explosion container shell is the zero point; u ρ is the radial displacement of the mid-plane of the explosion container shell; ρ, h, R and l0 represent the density, thickness, inner diameter and length of the explosion container shell respectively; N θ , Q x and Q θ They represent the hoop membrane force, axial shear force and hoop shear force per unit length of the mid-surface, respectively.

3. The calculation method for accurately predicting the deformation of a cylindrical explosion container according to claim 1, characterized in that: The spatiotemporal distribution of reflected overpressure P(x,t) is: Wherein, P0 is the peak overpressure of the pressure pulse at the center of the inner wall of the explosion container shell 1, a is the arrival time of the shock wave overpressure peak, and τ is the characteristic time constant describing the shock wave overpressure decay.

4. The calculation method for accurately predicting the deformation of a cylindrical explosion container according to claim 1, characterized in that: Where l1 is the length of the plastic deformation region, and u0(t) is the radial displacement time history curve at x=0.

5. The calculation method for accurately predicting the deformation of a cylindrical explosion container according to claim 1, characterized in that: The yield stress-plastic strain relationship of the explosion container shell is; Among them, σ y and σ0 are the flow stress and initial yield stress of the explosion container shell respectively; E p is the plastic hardening modulus, is the effective plastic strain.

6. The calculation method for accurately predicting the deformation of a cylindrical explosion container according to claim 5, characterized in that: Effective plastic strain Expressed as: Among them, ε θ , ε ρ and ε x denote hoop strain, radial strain and axial strain respectively, γ xρ Represents the shear strain between the axial and radial directions.

7. The calculation method for accurately predicting the deformation of a cylindrical explosion container according to claim 1, characterized in that: The length l1 of the plastic deformation area of ​​the explosion container shell is: in P0 is the peak overpressure of the pressure pulse at the center of the inner wall of the explosion container shell.

8. The calculation method for accurately predicting the deformation of a cylindrical explosion container according to claim 1, characterized in that: The radial displacement time history curve u0(t) at the center of the inner wall is: in,

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