Surface load analysis method for finite-size structures subjected to far-field blast waves

Abstract

The present application relates to a method for analyzing the surface load of a finite-size structure under the action of a far-field explosion wave, wherein the method comprises: determining shock wave parameters at a location of the finite-size structure based on explosion pressure parameters and environmental parameters, calculating the stagnation load on the surface of the structure and a first decay time history of the reflected overpressure based on the shock wave parameters; calculating the propagation speed of a diffraction wave on the surface of the structure based on the environmental parameters and the first decay time history, calculating the first moment when the diffraction wave reaches the target point and the second moment when the shock wave stagnates based on the speed and position parameters of the target point on the surface of the structure; calculating the second decay time history of the diffraction wave with respect to the reflected load based on the reflected overpressure on the surface of the structure at the first moment, the stagnation load at the second moment, the first moment, and the second moment; and determining the load time history of the target point based on the difference between the first decay time history and the second decay time history.

Description

Technical Field

[0001] The present application relates to the field of explosion shock wave load assessment, and in particular to a method for analyzing surface loads on finite-size structures under the action of far-field explosion waves. Background Art

[0002] Determining the load distribution of explosion shock waves on the surface of a structure is the basis for analyzing structural damage or dynamic response.

[0003] Existing technologies typically develop empirical formulas based on explosion test data or theoretical formulas based on the assumption that the structural surface is infinite. However, explosion tests present economic and safety issues, and due to limited test data, they are generally unsuitable for planar shock waves generated by far-field, large-yield explosions. Furthermore, theoretical load formulas based on the assumption that the structural surface is infinite are not suitable for predicting loads on structural surfaces of finite size.

[0004] Therefore, the existing technology is not accurate in analyzing the load distribution on the surface of finite-size structures, which may lead to erroneous damage assessment or dynamic response results. A better load distribution theoretical model needs to be constructed. Summary of the Invention

[0005] The embodiment of the present application provides a method for analyzing the surface load of a finite-size structure under the action of a far-field explosion wave, so as to at least solve the problem in the related art that the load distribution analysis results of the surface of a finite-size structure are inaccurate.

[0006] In a first aspect, an embodiment of the present application provides a method for analyzing surface loads on a finite-size structure under the action of a far-field explosion wave, comprising:

[0007] Determining shock wave parameters at a location of a finite-size structure based on explosion pressure parameters and environmental parameters, and calculating a stagnation load on a surface of the structure and a first decay time history of the reflected overpressure based on the shock wave parameters;

[0008] Calculating a propagation velocity of the diffraction wave on the surface of the structure according to the environmental parameters and the first attenuation time history, and calculating a first moment when the diffraction wave reaches the target point and a second moment when the shock wave stops according to the velocity and a position parameter of the target point on the surface of the structure;

[0009] Calculating a second decay time history of the diffracted wave to the reflected load based on the reflected overpressure on the surface of the structure at the first moment, the hysteresis load at the second moment, the first moment, and the second moment;

[0010] The load time history of the target point is determined according to the difference between the first decay time history and the second decay time history.

[0011] In one embodiment, the calculating, based on the velocity and the position parameters of the target point on the surface of the structure, the first moment when the diffracted wave reaches the target point and the second moment when the shock wave stops, comprises:

[0012] Calculating a vertical distance between the target point and the boundary of the structure surface, and calculating the first moment when the diffracted wave reaches the target point based on the vertical distance and the velocity;

[0013] Calculating the end time of the diffraction wave action based on the vertical distance between the parallel boundaries and the velocity;

[0014] The distance between the target point and the center point of the structure surface is calculated, and the second moment of shock wave stagnation is calculated according to the distance, the end moment and the speed.

[0015] In one embodiment, calculating the second decay time history of the diffracted wave to the reflected load based on the reflected overpressure on the surface of the structure at the first moment, the hysteresis load at the second moment, the first moment, and the second moment includes:

[0016] Calculating the attenuated load difference of the reflected load of the diffracted wave on the target point based on the reflected overpressure on the surface of the structure at the first moment and the hysteresis load at the second moment;

[0017] A second attenuation time history of the diffracted wave to the reflected load is calculated according to the attenuation load difference, the first moment and the second moment.

[0018] In one embodiment, calculating the attenuation load difference of the diffracted wave with respect to the reflected load of the target point, and calculating the second attenuation time history of the diffracted wave with respect to the reflected load, comprises:

[0019] AP(x,y)=P r (t1)-P s (t3).

[0020] The coordinate system is established with the midpoint of the bottom edge of the structure surface as the coordinate origin, the length direction as the x-axis, and the height direction as the y-axis. (x, y) is the coordinate of the target point, ΔP(x, y) is the attenuation load difference, and P r (t1) is the reflected overpressure on the surface of the structure at the first moment, P s (t3) is the stagnation load at the second moment;

[0021]

[0022] Where t is the moment when the shock wave acts, t1 is the first moment, t3 is the second moment, and k is the attenuation coefficient.

[0023] In one embodiment, determining the load time history of the target point according to the difference between the first attenuation time history and the second attenuation time history includes:

[0024] Calculate a first moment and a second moment corresponding to each boundary of the structure surface;

[0025] Calculating a second decay time history of the diffracted wave to the reflected load based on the reflected overpressure on the surface of the structure at the first moment, the stagnation load at the second moment, the first moment, and the second moment, and calculating a second decay time history corresponding to each of the boundaries;

[0026] The load time history of the target point is determined according to the difference between the first decay time history and the second decay time history corresponding to each boundary.

[0027] In one embodiment, determining the shock wave parameters at the location of the finite-size structure based on the explosion pressure parameters and the environmental parameters includes:

[0028] Determining the shock wave overpressure time history at the location of the finite-size structure based on the explosion pressure parameter;

[0029] The time history of the impact surge pressure at the location of the finite-size structure is determined according to the environmental parameters and the overpressure time history.

[0030] In one embodiment, the explosion pressure parameters include positive pressure action time, attenuation coefficient, and overpressure peak value. Determining the shock wave parameters at the location of the finite-size structure based on the explosion pressure parameters and environmental parameters includes:

[0031] Calculate the shock wave overpressure time history OP(t), specifically including:

[0032]

[0033] Among them, P m is the overpressure peak, t d is the positive pressure action time, k is the attenuation coefficient, and t is the moment of shock wave action;

[0034] The environmental parameters include the ambient atmospheric pressure and the air adiabatic index. The calculation of the shock wave pressure time history q(t) specifically includes:

[0035]

[0036] Where γ is the air adiabatic index, P0 is the ambient atmospheric pressure, and OP(t) is the time history of the shock wave overpressure.

[0037] In one embodiment, the calculating the propagation speed of the diffraction wave on the surface of the structure according to the environmental parameter and the first decay time history includes:

[0038]

[0039] Among them, γ is the air adiabatic index, P0 is the ambient atmospheric pressure, ρ is the atmospheric density, P r (t) is the first decay time history.

[0040] In a second aspect, an embodiment of the present application provides a system for analyzing surface loads on a finite-size structure under the action of a far-field explosion wave, comprising:

[0041] Reflection module: used to determine the shock wave parameters at the location of the finite-size structure based on the explosion pressure parameters and environmental parameters, and calculate the hysteresis load on the surface of the structure and the first decay time history of the reflected overpressure based on the shock wave parameters;

[0042] A time module is configured to calculate the propagation speed of the diffraction wave on the surface of the structure according to the environmental parameters and the first attenuation time history, and calculate the first moment when the diffraction wave reaches the target point and the second moment when the shock wave stops according to the speed and the position parameter of the target point on the surface of the structure;

[0043] Diffraction module: used to calculate the second attenuation time history of the diffracted wave to the reflected load based on the reflected overpressure on the structure surface at the first moment, the stagnation load at the second moment, the first moment and the second moment;

[0044] A determination module is configured to determine a load time history of a target point according to a difference between the first attenuation time history and the second attenuation time history.

[0045] In a third aspect, an embodiment of the present application provides a computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the method for analyzing surface loads of finite-size structures under the action of far-field explosion waves as described in the first aspect is implemented.

[0046] The surface load analysis method for a finite-size structure under the action of a far-field explosion wave provided in the embodiments of the present application has at least the following technical effects.

[0047] The method for analyzing surface loads on finite-sized structures subjected to far-field blast waves, provided in this application, takes into account the fact that the load on the surface of a finite-sized structure is the result of both reflection and diffraction, and that the time history of the load varies at different locations. Based on the attenuation of the reflected load by shock wave diffraction, as well as the degree of attenuation of shock wave diffraction at different locations on the structure's surface due to different boundaries, the method accurately predicts the load distribution and time history on the surface of the structure.

[0048] The details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0050] Figure 1 is a flow chart showing a method for analyzing surface loads on a finite-size structure under the action of a far-field explosion wave according to an exemplary embodiment;

[0051] Figure 2 is a schematic structural diagram illustrating the interaction between a far-field explosion wave and a finite-size structure according to an exemplary embodiment;

[0052] Figure 3 is a schematic diagram showing load time history data of a target point according to an exemplary embodiment;

[0053] Figure 4 is a partially enlarged schematic diagram showing load time history data of a target point according to an exemplary embodiment;

[0054] Figure 5 It is a schematic diagram of the load distribution on the structure surface at different times, which is displayed as an isoline diagram;

[0055] Figure 6 is a structural block diagram of a finite-size structure surface load analysis system under the action of far-field explosion waves according to an exemplary embodiment;

[0056] Figure 7 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is described and illustrated below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely used to explain this application and are not intended to limit this application. Based on the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without making any creative efforts are within the scope of protection of this application.

[0058] Obviously, the drawings described below are merely examples or embodiments of the present application. Those skilled in the art can, without inventive effort, apply the present application to other similar scenarios based on these drawings. Furthermore, it is also understood that, although the effort involved in such a development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, changes in design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as an insufficiency of the content disclosed in this application.

[0059] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it refer to independent or alternative embodiments that are mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments unless there is a conflict.

[0060] Unless otherwise defined, the technical or scientific terms used in this application should have the ordinary meaning understood by a person of ordinary skill in the technical field to which this application belongs. The words "one", "a", "the" and the like used in this application do not indicate a limit on quantity and may indicate the singular or plural. The terms "include", "comprise", "have" and any variations thereof used in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units that are inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The word "multiple" used in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, "A and / or B" can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific order for the objects.

[0061] In a first aspect, the embodiments of the present application provide a method for analyzing surface loads on finite-size structures under the action of far-field explosion waves. Figure 1FIG. 1 is a flow chart of a method for analyzing surface loads on a finite-size structure under the action of a far-field explosion wave according to an exemplary embodiment. Figure 1 As shown, the method includes:

[0062] Step S101 : determining shock wave parameters at a location of a finite-size structure based on explosion pressure parameters and environmental parameters, and calculating the hysteresis load on the surface of the structure and the first decay time history of the reflected overpressure based on the shock wave parameters.

[0063] Alternatively, the surface load analysis method for finite-size structures subjected to far-field blast waves provided in this application is primarily targeted at the surface of finite-size structures fixed to a horizontal, rigid surface. The surface of the structure refers to the surface facing the blast source, and the surface can be a square, rectangular, or other geometric shape.

[0064] The overpressure time history is described using the Friedlander expression, and the dynamic pressure time history is calculated using the Rankine-Hugoniot relationship. The overpressure time history is a function of the shock wave overpressure over time, and the dynamic pressure time history is a function of the shock wave pressure over time.

[0065] In one example, determining the shock wave parameters at the location of the finite-size structure according to the explosion pressure parameters and the environmental parameters in step S101 includes:

[0066] Step S1011 , determining the shock wave overpressure time history at the location of the finite-size structure according to the explosion pressure parameter.

[0067] Optionally, the explosion pressure parameters include the positive pressure action time, the attenuation coefficient, and the overpressure peak. The overpressure time history is described by the Friedlander expression. The specific calculation method of the shock wave overpressure time history OP(t) is as follows:

[0068]

[0069] Among them, P m is the overpressure peak, t d is the positive pressure action time, k is the attenuation coefficient, and t is the shock wave action time. Optionally, the parameters in this formula can be set according to specific experimental conditions or application conditions. In this application, the overpressure peak P m =120kPa, positive pressure action time t d =10ms, the attenuation coefficient is k=2.34.

[0070] Step S1012 : determining the time history of the shock surge pressure at the location of the finite-size structure according to the environmental parameters and the overpressure time history.

[0071] Optionally, the environmental parameters include ambient atmospheric pressure and air adiabatic index. The dynamic pressure time history is calculated according to the Rankine Hugoniot relationship. The specific calculation method of the shock wave pressure time history q(t) is as follows:

[0072]

[0073] Where γ is the air adiabatic index, P0 is the ambient atmospheric pressure, and OP(t) is the shock wave overpressure time history. The parameters in this formula can be set according to specific experimental conditions or application conditions. In this application, γ = 1.4 and the ambient atmospheric pressure P0 = 101 kPa.

[0074] In step S101, the stagnation load on the surface of the structure and the first decay time history of the reflected overpressure are calculated according to the shock wave parameters, including: calculating the reflected overpressure on the surface of the structure based on the shock wave reflected overpressure theory according to the shock wave parameters, and at the same time, the load on the surface of the structure gradually enters the stagnation stage from the reflected overpressure. r (t) and stagnation load P s The specific calculation method of (t) is as follows:

[0075] P r (t)=2OP(t)+(γ+1)q(t)

[0076] P s (t)=OP(t)+q(t)

[0077] Where OP(t) is the time history of the shock wave overpressure, q(t) is the time history of the shock wave pressure, and γ is the air adiabatic index.

[0078] Step S102, calculating the speed of the diffraction wave propagating on the surface of the structure according to the environmental parameters and the first attenuation time history, and the first moment when the diffraction wave reaches the target point and the second moment when the shock wave stops according to the speed and the position parameters of the target point on the surface of the structure.

[0079] Optionally, diffraction waves are generated by the structure's surface boundaries and propagate toward the center. The speed at which the diffraction waves propagate on the structure's surface is the speed of sound in the reflection region of the structure's surface where the shock wave is applied. Because the reflected overpressure on the structure's surface decays over time, the speed of the diffraction waves is a function of time.

[0080] In one example, calculating the speed a(t) of the diffraction wave propagating on the surface of the structure in step S102 specifically includes:

[0081]

[0082] Among them, γ is the air adiabatic index, P0 is the ambient atmospheric pressure, P r(t) is the first decay time history, and ρ is the atmospheric density, which is set to 1.29 kg / m in this formula. 3 .

[0083] In one example, calculating the first moment when the diffracted wave reaches the target point and the second moment when the shock wave stops in step S102 includes:

[0084] Step S1021 , calculating the vertical distance between the target point and the boundary of the structure surface, and calculating the first moment when the diffraction wave reaches the target point based on the vertical distance and the speed.

[0085] Optionally, a coordinate system is constructed on the surface of the structure to determine the position parameters of the target point on the surface. The origin and coordinate orientation of the coordinate system can be set as needed. For example, the coordinate center can be the center point of the structure surface, the midpoint of the base, or the endpoint of the base. The structure surface can have a geometric shape such as a square or rectangle.

[0086] In this application, a coordinate system is established with the midpoint of the bottom edge of the structure surface as the coordinate origin, the length direction as the X axis, and the height direction as the Y axis. The structure surface is a rectangle, where the length L = 2.4m and the height H = 1.2m. Assume that the coordinate range of the x, y target point is 0≤x≤L / 2, 0≤y≤H. When calculating the first moment when the boundary diffraction wave reaches the target point, taking the diffraction wave generated by the right boundary as an example, the distance between the target point and the right boundary is ΔS1 = L / 2-x. The specific formula for calculating the moment t1 when the diffraction wave of the right boundary reaches the target position is as follows:

[0087]

[0088] Where a(t) is the speed at which the diffraction wave propagates on the surface of the structure.

[0089] Step S1022: Calculate the end time of the diffraction wave action based on the vertical distance and velocity between the parallel boundaries.

[0090] Alternatively, the effect of the diffraction wave is considered to end when the diffraction wave propagates from one boundary to the other boundary. Assuming that the diffraction wave propagates from the left boundary to the right boundary, the distance is ΔS2 = L. The end time t2 of the diffraction wave effect is calculated as follows:

[0091]

[0092] Step S1023: Calculate the distance between the target point and the center point of the structure surface, and calculate the second moment of shock wave stagnation based on the distance, end time, and speed.

[0093] Optionally, after time t2, the diffraction wave effect at the boundary ends. Since there is still a difference in the load at each position on the structure surface and the center point of the structure surface, the stagnation pressure has not yet formed. The second time t3 at which the shock wave stagnates is calculated based on the distance ΔS3 = x between the target point and the center point of the structure surface. At this time, the load at the target point stagnates. The specific calculation formula is as follows:

[0094]

[0095] Among them, t2 is the end time of the diffraction wave, and a(t) is the speed of the diffraction wave propagating on the surface of the structure.

[0096] Step S103 , calculating a second decay time history of the diffracted wave to the reflected load according to the reflected overpressure on the surface of the structure at the first moment, the hysteresis load at the second moment, the first moment and the second moment.

[0097] Optionally, the load attenuation process of the target point within the time interval t3 to t1 caused by the diffraction wave generated by the boundary is described by a Friedlander expression.

[0098] In one example, step S103 includes:

[0099] Step S1031, calculate the attenuation load difference ΔP of the reflection load of the diffracted wave on the target point based on the reflection overpressure on the structure surface at the first moment and the stagnation load at the second moment. The specific calculation formula is as follows:

[0100] ΔP(x,y)=P r (t1)-P s (t3).

[0101] Where (x, y) is the coordinate of the target point, ΔP(x, y) is the attenuation load difference, P r (t1) is the reflected overpressure on the surface of the structure at the first moment, P s (t3) is the hysteresis load at the second moment.

[0102] Step S1032: Calculate the second attenuation time history of the diffraction wave to the reflected load based on the attenuation load difference, the first moment and the second moment. The second attenuation time history is the load attenuation process P of the target point within the time interval t3 to t1 caused by the diffraction wave generated by the boundary. c The specific calculation formula is as follows:

[0103]

[0104] Among them, (x, y) is the coordinate of the target point, t is the moment of shock wave action, t1 is the first moment when the diffraction wave reaches the target point, t3 is the second moment when the shock wave stops, and k is the attenuation coefficient.

[0105] Step S104 : determining the load time history of the target point according to the difference between the first decay time history and the second decay time history.

[0106] For a rectangular structure surface, there are four boundaries, so the attenuation loads of the diffracted waves generated by the four boundaries are superimposed as the total attenuation load. The function of the load change of the target point over time is determined based on the difference between the first attenuation time history and the total attenuation load.

[0107] This method, taking into account that the load on a structure's surface is the result of both reflection and diffraction, and that the time history of the load varies at different locations, accurately predicts the load distribution and time history on the structure's surface based on the attenuation of the reflected load by shock wave diffraction, as well as the degree of attenuation of shock wave diffraction at different locations on the structure's surface due to different boundaries. Compared to traditional experimental or numerical methods, this method can quickly and accurately predict the load distribution on the surface of finite-sized structures subjected to far-field explosion shock waves.

[0108] In one example, step S104 includes:

[0109] Step S1041 , calculating a first moment and a second moment corresponding to each boundary of the structure surface.

[0110] Step S1042, based on the reflected overpressure on the surface of the structure at the first moment, the stagnation load at the second moment, the first moment and the second moment, calculate the second attenuation time history of the diffraction wave to the reflected load, and the second attenuation time history corresponding to each of the boundaries.

[0111] Step S1043 : determining the load time history of the target point according to the first decay time history and the second decay time history corresponding to each boundary.

[0112] Optionally, considering that there are multiple boundaries on the surface of the structure, it is necessary to add the attenuation load caused by the diffraction waves generated by each boundary as the total attenuation load. The specific calculation formula is as follows:

[0113]

[0114] x, y are the coordinates of the target point, t is the time when the shock wave acts, P c The load attenuation process at a target point caused by a single boundary, where i represents the boundary number, is shown. The structural surface used in this embodiment is rectangular and has four boundaries. In this way, based on the attenuation of reflected loads by shock wave diffraction, and taking into account the differences in shock wave load histories at different locations on the structural surface, the load distribution and time history of the structural surface can be accurately predicted.

[0115] The above is the calculation process of the surface load analysis method of the finite-size structure under the action of the far-field blast wave provided in this application. The effect of the surface load analysis method of the finite-size structure under the action of the far-field blast wave adopted in this application will be analyzed below.

[0116] As an example, the present application sets the overpressure peak value of the explosion shock wave to be P m =120kPa, positive pressure action time t d The geometric parameters of the structure facing the explosion source are as follows: length L = 2.4m, height H = 1.2m. Figure 2 FIG. 1 is a schematic diagram showing the interaction between a far-field explosion wave and a finite-size structure according to an exemplary embodiment. Figure 2 As shown, three equal points are selected on the surface of the structure in the height direction and four equal points are selected in the length direction to obtain four points A, B, C and D for outputting the load time history curve.

[0117] Figure 3 FIG1 is a schematic diagram showing load-time history data of target points according to an exemplary embodiment, specifically load-time history curves of four points A, B, C, and D. ... Figure 4 FIG. 1 is a partially enlarged schematic diagram showing load time history data of a target point according to an exemplary embodiment. Figure 4 yes Figure 3 A local enlarged view is shown to more clearly show the differences in load time history at different locations. Figure 5 The load distribution diagram of the structure surface at different times is shown in the contour map. Since the coordinate system is established with the midpoint of the bottom edge as the origin, the direction is the X axis, and the height direction is the Y axis, it has bilateral symmetry. Figure 5 Only the right half of the cloud is shown.

[0118] The results show that the surface load analysis method of a finite-size structure under the action of a far-field explosion wave provided in this application can calculate the load distribution data of a far-field explosion wave acting on a finite-size structure. This method can characterize the differences in the load history of the explosion shock wave acting at different positions of the structure, and can provide more detailed and accurate data for studying the damage assessment or response analysis of the structure after being subjected to the explosion load.

[0119] In summary, the surface load analysis method for finite-sized structures subjected to far-field blast waves provided in this application takes into account that the load on the structure's surface is the result of a combination of reflection and diffraction, and that the load time history varies at different locations when a planar blast wave acts on the structure. This method accurately predicts the load distribution and time history on the structure's surface based on the attenuation of the reflected load by shock wave diffraction, as well as the degree of attenuation of shock wave diffraction at different locations on the structure's surface due to different boundaries. Compared to traditional experimental or numerical methods, this method can quickly and accurately predict the surface load distribution of finite-sized structures subjected to far-field blast waves.

[0120] In a second aspect, the present invention provides a system for analyzing surface loads on finite-size structures under the action of far-field explosion waves. Figure 6 FIG. 1 is a structural block diagram of a finite-size structure surface load analysis system under the action of a far-field explosion wave according to an exemplary embodiment. Figure 6 As shown, the system includes:

[0121] Reflection module 100: used to determine the shock wave parameters at the location of the finite-size structure based on the explosion pressure parameters and environmental parameters, and calculate the hysteresis load on the surface of the structure and the first decay time history of the reflected overpressure based on the shock wave parameters.

[0122] Time module 200: used to calculate the speed of the diffraction wave propagating on the structure surface based on the environmental parameters and the first attenuation time history, and calculate the first moment when the diffraction wave reaches the target point and the second moment when the shock wave stops based on the speed and the position parameters of the target point on the structure surface.

[0123] Diffraction module 300: used to calculate the second attenuation time history of the diffraction wave to the reflected load based on the reflected overpressure of the structure surface at the first moment, the hysteresis load at the second moment, the first moment and the second moment.

[0124] Determination module 400: used to determine the load time history of the target point according to the difference between the first decay time history and the second decay time history.

[0125] In one example, the time module 200 includes:

[0126] The first moment unit is used to calculate the vertical distance between the target point and the boundary of the structure surface, and calculate the first moment when the diffraction wave reaches the target point according to the vertical distance and the speed.

[0127] End time unit: used to calculate the end time of diffraction wave action based on the vertical distance and velocity between parallel boundaries.

[0128] Second moment unit: used to calculate the distance between the target point and the center point of the structure surface, and calculate the second moment of shock wave stagnation based on the distance, end time and speed.

[0129] In one example, the diffraction module 300 includes:

[0130] Attenuated load difference unit: used to calculate the attenuated load difference of the reflected load of the diffracted wave on the target point based on the reflected overpressure on the structure surface at the first moment and the stagnation load at the second moment.

[0131] Attenuation load time unit: used to calculate the second attenuation time history of the diffraction wave to the reflected load based on the attenuation load difference, the first moment and the second moment.

[0132] In one example, the diffraction module 300 includes:

[0133] ΔP(x,y)=P r (t1)-P s (t3).

[0134] The coordinate system is established with the midpoint of the bottom edge of the structure surface as the coordinate origin, the length direction as the x-axis, and the height direction as the y-axis. (x, y) is the coordinate of the target point, ΔP(x, y) is the attenuation load difference, and P r (t1) is the reflected overpressure on the surface of the structure at the first moment, P s (t3) is the stagnation load at the second moment;

[0135]

[0136] Where t is the moment when the shock wave acts, t1 is the first moment, t3 is the second moment, and k is the attenuation coefficient.

[0137] In one example, the determination module 400 includes:

[0138] Moment unit: used to calculate the first moment and second moment corresponding to each boundary of the structure surface.

[0139] Attenuation unit: used to calculate the second attenuation time history of the diffraction wave to the reflected load based on the reflected overpressure on the structure surface at the first moment, the stagnation load at the second moment, the first moment and the second moment, and calculate the second attenuation time history corresponding to each boundary.

[0140] Determining unit: used for determining the load time history of the target point according to the difference between the first decay time history and the second decay time history corresponding to each boundary.

[0141] In one example, the reflection module 100 includes:

[0142] Overpressure unit: used to determine the shock wave overpressure time history at the location of a finite-sized structure based on the explosion pressure parameters.

[0143] Dynamic pressure unit: used to determine the time history of the shock wave pressure at the location of the finite size structure based on environmental parameters and overpressure time history.

[0144] In one example, the reflection module 100 includes:

[0145] Calculate the shock wave overpressure time history OP(t), specifically including:

[0146]

[0147] Among them, P m is the overpressure peak, t d is the positive pressure action time, k is the attenuation coefficient, and t is the moment of shock wave action;

[0148] The environmental parameters include the ambient atmospheric pressure and the air adiabatic index. The calculation of the shock wave pressure time history q(t) specifically includes:

[0149]

[0150] Where γ is the air adiabatic index, P0 is the ambient atmospheric pressure, and OP(t) is the time history of the shock wave overpressure.

[0151] In one example, the reflection module 100 includes:

[0152]

[0153] Among them, γ is the air adiabatic index, P0 is the ambient atmospheric pressure, ρ is the atmospheric density, P r (t) is the first decay time history.

[0154] In summary, the surface load analysis system for finite-sized structures subjected to far-field blast waves provided by this application takes into account that the load on the structure's surface is the result of both reflection and diffraction, and that the load time histories vary at different locations when a planar blast wave acts on the structure. This system accurately predicts the load distribution and time history on the structure's surface based on the attenuation of the reflected load by shock wave diffraction, as well as the degree of attenuation of shock wave diffraction at different locations on the structure's surface due to different boundaries. Compared to traditional experimental or numerical prediction methods, this system can quickly and accurately predict the surface load distribution of finite-sized structures subjected to far-field blast waves.

[0155] In a third aspect, an embodiment of the present application provides an electronic device, Figure 7This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the method for analyzing surface loads on finite-sized structures under far-field explosion waves provided in the first aspect. Figure 7 The electronic device 60 shown is only an example and should not limit the functions and scope of use of the embodiments of the present application.

[0156] The electronic device 60 may be a general-purpose computing device, such as a server device. Components of the electronic device 60 may include, but are not limited to, the at least one processor 61, the at least one memory 62, and a bus 63 connecting different system components (including the memory 62 and the processor 61).

[0157] The bus 63 includes a data bus, an address bus, and a control bus.

[0158] The memory 62 may include a volatile memory, such as a random access memory (RAM) 621 and / or a cache memory 622 , and may further include a read-only memory (ROM) 623 .

[0159] The memory 62 may also include a program / utility 625 having a set (at least one) of program modules 624, such program modules 624 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0160] The processor 61 executes various functional applications and data processing by running the computer programs stored in the memory 62, such as the surface load analysis method of a finite-size structure under the action of a far-field explosion wave according to the first aspect of the present application.

[0161] The electronic device 60 can also communicate with one or more external devices 64 (e.g., a keyboard, pointing device, etc.). This communication can occur via an input / output (I / O) interface 65. Furthermore, the model-generating device 60 can also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 66. As shown, the network adapter 66 communicates with other modules of the model-generating device 60 via a bus 63. It should be understood that, although not shown, other hardware and / or software modules can be used in conjunction with the model-generating device 60, including but not limited to microcode, device drivers, redundant processors, external disk drive arrays, RAID (RAID) systems, tape drives, and data backup storage systems.

[0162] It should be noted that although several units / modules or sub-units / modules of the electronic device are mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of the present invention, the features and functions of two or more units / modules described above may be embodied in a single unit / module. Conversely, the features and functions of a single unit / module described above may be further divided and embodied by multiple units / modules.

[0163] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0164] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A method for analyzing surface loads on finite-size structures under far-field explosion waves, characterized in that: include: Determining shock wave parameters at a location of a finite-size structure based on explosion pressure parameters and environmental parameters, and calculating a stagnation load on a surface of the structure and a first decay time history of the reflected overpressure based on the shock wave parameters; Calculating a propagation velocity of the diffraction wave on the surface of the structure according to the environmental parameters and the first attenuation time history, and calculating a first moment when the diffraction wave reaches the target point and a second moment when the shock wave stops according to the velocity and a position parameter of the target point on the surface of the structure; Calculating a second decay time history of the diffracted wave to the reflected load based on the reflected overpressure on the surface of the structure at the first moment, the stagnation load at the second moment, the first moment, and the second moment, including: The attenuation load difference of the reflected load of the diffracted wave on the target point is calculated based on the reflected overpressure of the structure surface at the first moment and the stagnation load at the second moment. The calculation formula is: ΔP(x,y)=P r (t1)-P s (t3) The coordinate system is established with the midpoint of the bottom edge of the structure surface as the coordinate origin, the length direction as the x-axis, and the height direction as the y-axis. (x, y) is the coordinate of the target point, ΔP(x, y) is the attenuation load difference, and P r (t1) is the reflected overpressure on the surface of the structure at the first moment, P s (t3) is the hysteresis load at the second moment, The second attenuation time history of the diffracted wave to the reflected load is calculated according to the attenuation load difference, the first moment and the second moment, and the calculation formula is: Among them, P c (x, y, t) is the second attenuation time history, which characterizes the load attenuation process caused by any boundary on the surface of the structure, t is the moment of shock wave action, t1 is the first moment, t3 is the second moment, and k is the attenuation coefficient; Determining the load time history of the target point according to the difference between the first attenuation time history and the second attenuation time history includes: superimposing the attenuation load caused by the diffraction wave generated by each boundary of the structure surface as the total attenuation load.

2. The method for analyzing surface loads on finite-size structures under far-field explosion waves according to claim 1 is characterized in that: Calculating the first moment when the diffraction wave reaches the target point and the second moment when the shock wave stops according to the velocity and the position parameters of the target point on the surface of the structure includes: calculating a vertical distance between the target point and a boundary of the structure surface, and calculating a first moment when the diffracted wave reaches the target point based on the vertical distance and the velocity; Calculating the end time of the diffraction wave action based on the vertical distance between the parallel boundaries and the velocity; The distance between the target point and the center point of the structure surface is calculated, and the second moment of shock wave stagnation is calculated according to the distance, the end moment and the speed.

3. The method for analyzing surface loads on finite-size structures under far-field explosion waves according to claim 2 is characterized in that: Determining the load time history of the target point according to the difference between the first attenuation time history and the second attenuation time history includes: Calculate a first moment and a second moment corresponding to each boundary of the structure surface; Calculating a second decay time history of the diffracted wave to the reflected load based on the reflected overpressure on the surface of the structure at the first moment, the stagnation load at the second moment, the first moment, and the second moment, and calculating a second decay time history corresponding to each of the boundaries; The load time history of the target point is determined according to the difference between the first decay time history and the second decay time history corresponding to each boundary.

4. The method for analyzing surface loads on finite-size structures under far-field explosion waves according to claim 1 is characterized in that: The method of determining the shock wave parameters at the location of the finite-size structure according to the explosion pressure parameters and the environmental parameters includes: Determining the shock wave overpressure time history at the location of the finite-size structure based on the explosion pressure parameter; The time history of the impact surge pressure at the location of the finite-size structure is determined according to the environmental parameters and the overpressure time history.

5. The method for analyzing surface loads on finite-size structures under far-field explosion waves according to claim 4 is characterized in that: The explosion pressure parameters include the positive pressure action time, the attenuation coefficient and the overpressure peak value. The shock wave parameters at the location of the finite size structure are determined based on the explosion pressure parameters and the environmental parameters, including: Calculate the shock wave overpressure time history OP(t), specifically including: Among them, P m is the overpressure peak, t d is the positive pressure action time, k is the attenuation coefficient, and t is the moment of shock wave action; The environmental parameters include the ambient atmospheric pressure and the air adiabatic index. The calculation of the shock wave pressure time history q(t) specifically includes: Where γ is the air adiabatic index, P0 is the ambient atmospheric pressure, and OP(t) is the time history of the shock wave overpressure.

6. The method for analyzing surface loads on finite-size structures under far-field explosion waves according to claim 1, characterized in that: The calculating the propagation speed of the diffraction wave on the surface of the structure according to the environmental parameter and the first attenuation time history includes: Among them, γ is the air adiabatic index, P0 is the ambient atmospheric pressure, ρ is the atmospheric density, P r (t) is the first decay time history.

7. A finite-size structure surface load analysis system under far-field explosion wave action, characterized in that: include: Reflection module: used to determine the shock wave parameters at the location of the finite-size structure based on the explosion pressure parameters and environmental parameters, and calculate the hysteresis load on the surface of the structure and the first decay time history of the reflected overpressure based on the shock wave parameters; A time module is configured to calculate the propagation speed of the diffraction wave on the surface of the structure according to the environmental parameters and the first attenuation time history, and calculate the first moment when the diffraction wave reaches the target point and the second moment when the shock wave stops according to the speed and the position parameter of the target point on the surface of the structure; A diffraction module is configured to calculate a second attenuation time history of the diffracted wave to the reflected load based on the reflected overpressure on the surface of the structure at the first moment, the stagnation load at the second moment, the first moment, and the second moment, including: The attenuation load difference of the reflected load of the diffracted wave on the target point is calculated based on the reflected overpressure of the structure surface at the first moment and the stagnation load at the second moment. The calculation formula is: ΔP(x,y)=P r (t1)-P s (t3) The coordinate system is established with the midpoint of the bottom edge of the structure surface as the coordinate origin, the length direction as the x-axis, and the height direction as the y-axis. (x, y) is the coordinate of the target point, ΔP(x, y) is the attenuation load difference, and P r (t1) is the reflected overpressure on the surface of the structure at the first moment, P s (t3) is the hysteresis load at the second moment, The second attenuation time history of the diffracted wave to the reflected load is calculated according to the attenuation load difference, the first moment and the second moment, and the calculation formula is: Among them, P c (x, y, t) is the second attenuation time history, which characterizes the load attenuation process caused by any boundary on the surface of the structure, t is the moment of shock wave action, t1 is the first moment, t3 is the second moment, and k is the attenuation coefficient; A determination module is used to determine the load time history of the target point according to the difference between the first attenuation time history and the second attenuation time history, including: superimposing the attenuation load caused by the diffraction wave generated by each boundary of the structure surface as the total attenuation load.

8. An electronic device, characterized in that: include Memory, processor, and A computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for analyzing surface loads on a finite-size structure under the action of a far-field explosion wave according to any one of claims 1 to 6 is implemented.

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