A method and system for calculating engine explosion impact load

Abstract

The present invention provides a method and system for calculating an engine explosion impact load, comprising: a load calculation step: calculating an intermediate process quantity of the explosion impact load based on the mass of an engine assembly, and using the intermediate process quantity to respectively calculate the impact loads in the Z direction and the XY direction; a calculation processing step: processing an engine model to obtain a finite element model, and setting a suspension stiffness and boundary conditions for the finite element model; a loading step: loading the Z direction and the XY direction impact loads to the load application point position of the finite element model, calculating the engine center of mass acceleration; and extracting the maximum value of the acceleration load at the center of mass in the X, Y, and Z directions as the actual explosion impact load for calculating the engine.

Description

Technical Field

[0001] The present invention belongs to the technical field of engine impact assessment, and in particular relates to a method and system for calculating engine explosion impact load. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Due to the high energy of the explosion shock wave, it is necessary to verify the reliability of the engine in this special scenario. The explosion shock wave is the pressure fluctuation of the air or liquid medium generated by the explosion. Existing engines do not accurately assess the engine's shock resistance during the design process, focusing on shock resistance calculations.

[0004] In addition, since the reliability verification requirements of the engine in this special working scenario are different from those of conventional products, the reliability verification requirements of conventional products cannot be applied to the engine impact reliability assessment. Summary of the Invention

[0005] In order to solve the above problems, the present invention proposes a method for calculating the engine explosion impact load. The present invention utilizes load calculation and calculation processing, and finally evaluates the calculation results, which can realize the verification of engine reliability.

[0006] According to some embodiments, the present invention adopts the following technical solutions:

[0007] In a first aspect, a method for calculating an engine explosion impact load is disclosed, comprising:

[0008] Load calculation steps: Calculate the intermediate process quantity of the explosion impact load based on the mass of the engine assembly, and use the intermediate process quantity to calculate the impact load in the Z direction and XY direction respectively;

[0009] Calculation processing steps: Process the engine model to obtain a finite element model, and set the mount stiffness and boundary conditions for the finite element model;

[0010] Loading step: Apply Z-axis and XY-axis impact loads to the load application points of the above finite element model and calculate the engine center of mass acceleration;

[0011] The maximum acceleration load at the center of mass in the X, Y, and Z directions is extracted to calculate the actual explosion impact load of the engine.

[0012] As a further technical solution, the mass of the engine assembly includes wet weight.

[0013] As a further technical solution, the processing of the engine model specifically includes: dividing the engine model into grids, and controlling the grid nodes within a set range.

[0014] As a further technical solution, when setting the suspension stiffness and boundary conditions:

[0015] The suspension stiffness is replaced by a spring unit, and the stiffness in the spring unit needs to be set to static stiffness;

[0016] Set the engine mass at the engine center of mass;

[0017] The engine material is set to Ruili damping;

[0018] The load application point is established at the center point of the engine bottom, and a rigid coupling constraint is established between the load application point and the engine base.

[0019] As a further technical solution, an evaluation step is also included: extracting the maximum principal stress of the calculation results and evaluating the calculation results based on the tensile strength of the material to be evaluated.

[0020] In a second aspect, a system for calculating engine explosion impact load is disclosed, comprising:

[0021] The load calculation module is configured to calculate an intermediate process quantity of the explosion impact load based on the mass of the engine assembly, and calculate the impact loads in the Z direction and the XY direction respectively using the intermediate process quantity;

[0022] The calculation processing module is configured to: process the engine model to obtain a finite element model, and set the suspension stiffness and boundary conditions for the finite element model;

[0023] The loading module is configured to: apply Z-direction and XY-direction impact loads to the load application point of the finite element model and calculate the engine center of mass acceleration;

[0024] The maximum acceleration load at the center of mass in the X, Y, and Z directions is extracted to calculate the actual explosion impact load of the engine.

[0025] As a further technical solution, an evaluation module is also included, which is configured to: extract the maximum principal stress of the calculation results and evaluate the calculation results based on the tensile strength of the material to be evaluated.

[0026] As a further technical solution, when setting the suspension stiffness and boundary conditions, the calculation processing module:

[0027] The suspension stiffness is replaced by a spring unit, and the stiffness in the spring unit needs to be set to static stiffness;

[0028] Set the engine mass at the engine center of mass;

[0029] The engine material is set to Ruili damping;

[0030] The load application point is established at the center point of the engine bottom, and a rigid coupling constraint is established between the load application point and the engine base.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The above-mentioned technical solution disclosed in the present invention takes into account the mass of the engine assembly in the calculation of the engine explosion impact load. Only the engine mass needs to be input, and the Z-direction and XY-direction impact loads can be calculated. The explosion impact load can be accurately obtained and provided as an input for the subsequent model loading.

[0033] The above technical solution disclosed in the present invention processes the engine model and sets the engine suspension stiffness and boundary conditions. Through the above settings, the Z-direction and XY-direction loads calculated in the first step can be loaded to the load application point position while meeting the required requirements, thereby realizing accurate calculation of the engine center of mass acceleration.

[0034] Advantages of additional aspects of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0037] Figure 1 Flow chart of calculation method for engine impact reliability;

[0038] Figure 2 Schematic diagram of the positions of a1, a2, t1, and t2 in the impact load spectrum;

[0039] Figure 3 Schematic diagram of the positions of a3, a4, t3, and t4 in the impact load spectrum;

[0040] Figure 4 This is a schematic diagram of the engine load calculation program interface;

[0041] Figure 5 Schematic diagram of the calculated center of mass acceleration load. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0043] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0044] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0045] Example 1:

[0046] See attached Figure 1 As shown, in this embodiment, a method for calculating engine explosion impact load is disclosed, including:

[0047] Load calculation steps: Calculate the intermediate process quantity of the explosion impact load based on the mass of the engine assembly, and use the intermediate process quantity to calculate the impact load in the Z direction and XY direction respectively;

[0048] Calculation processing steps: Process the engine model to obtain a finite element model, and set the mount stiffness and boundary conditions for the finite element model;

[0049] Loading step: Apply Z-axis and XY-axis impact loads to the load application points of the above finite element model and calculate the engine center of mass acceleration;

[0050] The maximum acceleration load at the center of mass in the X, Y, and Z directions is extracted to calculate the actual explosion impact load of the engine.

[0051] The method is mainly divided into two parts: load calculation and calculation processing, and finally the evaluation of the calculation results. In the load calculation part, a new load calculation program was developed.

[0052] Load calculation steps:

[0053] The main purpose of load calculation is to calculate the explosion impact load and provide the input of explosion impact for the subsequent calculation model loading.

[0054] First, provide the mass of the engine assembly (including the wet weight of lubricating oil, etc.) as input for the load calculation part.

[0055] According to the mass of the whole machine, the intermediate process quantity of the explosion impact load is calculated as follows:

[0056] b7=320*(m / 5) -0.5

[0057] c7=7.5*(m / 5) -0.4

[0058] d7=4.5

[0059] b8=280*(m / 5) -0.5

[0060] c8=6*(m / 5) -0.4

[0061] d8=3

[0062] The impact loads in the Z direction (vertical) and the XY direction (lateral) are calculated based on the above intermediate process quantities b7, c7, d7, b8, c8, and d8.

[0063] The Z-direction impact load is calculated as follows:

[0064] a1=0.5*b7

[0065] v1=2 / 3*c7

[0066] t1=2.5*π*c7 / (3*b7*9.8)*1000

[0067] t2=2.5*d7 / (100*v1)*1000-t1

[0068] a2=-π*v1 / 2*(1000 / 42.8) / 9.8

[0069] The XY impact load is calculated as follows:

[0070] a3=0.5*b8

[0071] v3=2 / 3*c8

[0072] t3=2*π*c8 / (3*b8*9.8)*1000

[0073] t4=2*d8 / (100*v3)*1000-t1

[0074] a4=-π*v3 / 2*(1000 / 42.8) / 9.8

[0075] Among them, the positions of a1, a2, t1, t2, a3, a4, t3, and t4 in the impact load spectrum are as follows: Figure 2 、 3 shown.

[0076] Function image in Z direction:

[0077] T1=i*time_interval_1#Time of the first segment

[0078] w1=π / t1

[0079] fun_cur_1=a1*9.8*sin(w1*T1)#Function of segment t1

[0080] T2=i*time_interval_2#Time of the second segment

[0081] w2=π / t2

[0082] fun_cur_2=a2*9.8*sin(w2*T2) # Function of segment t2

[0083] Function graph in XY direction:

[0084] T3 = i*time_interval_1 #time of the first segment

[0085] w1=π / t3

[0086] fun_cur_1=a3*9.8*sin(w1*T1) # Function of segment t1

[0087] T4=i*time_interval_2#Time of the second segment

[0088] w2=π / t4

[0089] fun_cur_2=a4*9.8*sin(w2*T2) # Function of segment t2

[0090] Where i is an integer from 0 to 30, time_interval_1 is the image of the first segment, and time_interval_2 is the time interval of the second segment. When i = 30, T1 = t1, T2 = t2, T3 = t3, and T4 = t4;

[0091] Write the engine load calculation program interface as follows Figure 4 As shown in the figure, just input the engine mass and the Z-axis and XY-axis impact loads can be calculated.

[0092] Calculation processing steps:

[0093] The main purpose of the computational processing section is to process the engine model that needs to be calculated. First, the engine model is meshed, and the mesh type uses C3D4 elements. Considering the computational cost, the mesh nodes are controlled to less than 1 million. After the mesh model is processed, the finite element model is obtained. Next, the engine mount stiffness and boundary conditions need to be set. Among them, the mount stiffness is replaced by spring elements. The stiffness in the spring element needs to be set to static stiffness, and the spring damping ratio is set to 0.05. The engine mass is set at the center of the engine mass. The engine material needs to be set to Ruili damping, and the Ruili damping coefficients are set to 0.25 and 0.003 respectively. The coefficients of the remaining items are set to 0. The load application point is established at the center point of the engine bottom, and an RBE2 rigid coupling constraint is established between the load application point and the engine base.

[0094] After processing the finite element model, the implicit dynamics calculation method is used to load the Z-axis and XY-axis loads calculated in the first step to the load application point, that is, the rigid coupling constraint point, and calculate the engine center of mass acceleration. Taking a certain engine as an example, the calculated center of mass acceleration load is as follows: Figure 5 shown.

[0095] Finally, calculate the model strength and evaluate the calculation results

[0096] The maximum acceleration loads at the center of mass in the X, Y, and Z directions are extracted to calculate the actual explosion impact load on the engine. Implicit dynamics extracts these loads and applies them to the statics calculation model. The model is then rebuilt, using statics calculation methods to apply the impact load to the center of mass. At this point, the engine mesh model needs to be modified to C3D10M elements.

[0097] When evaluating calculation results, the center-of-mass acceleration load is input to the statics calculation. The maximum principal stress is calculated using statics, and the results are evaluated using the tensile strength of the material being evaluated. If the maximum principal stress is less than the tensile strength limit, the evaluation requirement is met; otherwise, it is not met.

[0098] Example 2:

[0099] Based on the method of embodiment 1, a system for calculating engine explosion impact load is disclosed, including:

[0100] The load calculation module is configured to calculate an intermediate process quantity of the explosion impact load based on the mass of the engine assembly, and calculate the impact loads in the Z direction and the XY direction respectively using the intermediate process quantity;

[0101] The calculation processing module is configured to: process the engine model to obtain a finite element model, and set the suspension stiffness and boundary conditions for the finite element model;

[0102] The loading module is configured to: apply Z-direction and XY-direction impact loads to the load application point of the finite element model and calculate the engine center of mass acceleration;

[0103] The maximum acceleration load at the center of mass in the X, Y, and Z directions is extracted to calculate the actual explosion impact load of the engine.

[0104] In this embodiment, an evaluation module is further included, which is configured to: extract the maximum principal stress of the calculation result, and evaluate the calculation result based on the tensile strength of the material to be evaluated.

[0105] In this embodiment, when setting the suspension stiffness and boundary conditions, the calculation processing module:

[0106] The suspension stiffness is replaced by a spring unit, and the stiffness in the spring unit needs to be set to static stiffness;

[0107] Set the engine mass at the engine center of mass;

[0108] The engine material is set to Ruili damping;

[0109] The load application point is established at the center point of the engine bottom, and a rigid coupling constraint is established between the load application point and the engine base.

[0110] Example 3:

[0111] The purpose of this embodiment is to provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the program.

[0112] Example 4

[0113] The purpose of this embodiment is to provide a computer-readable storage medium.

[0114] A computer-readable storage medium stores a computer program, which, when executed by a processor, performs the steps of the above method.

[0115] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0116] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0117] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0118] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0119] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

[0120] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A method for calculating engine explosion impact load, characterized in that: include: Load calculation steps: Calculate the intermediate process quantity of the explosion impact load based on the mass of the engine assembly, and use the intermediate process quantity to calculate the impact load in the Z direction and XY direction respectively; Calculation processing steps: Process the engine model to obtain a finite element model, set the suspension stiffness and boundary conditions for the finite element model, where the boundary conditions include: setting the engine mass at the engine center of mass; setting the engine material to Ruili damping; establishing the load application point at the center point of the engine bottom, and establishing a rigid coupling constraint between the load application point and the engine base; Loading step: Apply Z-axis and XY-axis impact loads to the load application points of the above finite element model and calculate the engine center of mass acceleration; The maximum acceleration load at the center of mass in the X, Y, and Z directions is extracted to calculate the actual explosion impact load of the engine.

2. The method for calculating engine explosion impact load according to claim 1, wherein: The mass of the engine assembly includes the wet weight.

3. The method for calculating engine explosion impact load according to claim 1, wherein: The processing of the engine model specifically includes: dividing the engine model into grids, and controlling grid nodes within a set range.

4. The method for calculating engine explosion impact load according to claim 1, wherein: When setting the mount stiffness and boundary conditions: The suspension stiffness is replaced by a spring unit, and the stiffness in the spring unit needs to be set to static stiffness; Set the engine mass at the engine center of mass; The engine material is set to Ruili damping; The load application point is established at the center point of the engine bottom, and a rigid coupling constraint is established between the load application point and the engine base.

5. A method for calculating engine explosion impact load according to any one of claims 1 to 4, characterized in that: The method also includes an evaluation step: extracting the maximum principal stress of the calculation results and evaluating the calculation results based on the tensile strength of the material to be evaluated.

6. An engine explosion impact load calculation system, characterized in that: include: The load calculation module is configured to calculate an intermediate process quantity of the explosion impact load based on the mass of the engine assembly, and calculate the impact loads in the Z direction and the XY direction respectively using the intermediate process quantity; The calculation processing module is configured to: process the engine model to obtain a finite element model, set the suspension stiffness and boundary conditions for the finite element model, wherein the boundary conditions include: setting the engine mass at the engine center of mass; setting the engine material to Ruili damping; establishing a load application point at the center point of the engine bottom, and establishing a rigid coupling constraint between the load application point and the engine base; The loading module is configured to: apply Z-direction and XY-direction impact loads to the load application point of the finite element model and calculate the engine center of mass acceleration; The maximum acceleration load at the center of mass in the X, Y, and Z directions is extracted to calculate the actual explosion impact load of the engine.

7. The engine explosion impact load calculation system according to claim 6, characterized in that: The system also includes an evaluation module configured to extract the maximum principal stress of the calculation results and evaluate the calculation results based on the tensile strength of the material to be evaluated.

8. The engine explosion impact load calculation system according to claim 6, characterized in that: When setting the suspension stiffness and boundary conditions, the calculation processing module: The suspension stiffness is replaced by a spring unit, and the stiffness in the spring unit needs to be set to static stiffness; Set the engine mass at the engine center of mass; The engine material is set to Ruili damping; The load application point is established at the center point of the engine bottom, and a rigid coupling constraint is established between the load application point and the engine base.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method described in any one of claims 1 to 5 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method described in any one of claims 1 to 5 are executed.

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