Method for predicting the lifetime of a charging gun cable, lifetime prediction device

Abstract

The application provides a life prediction method and device for a charging gun wire, which comprises the following steps: extracting stress-strain curves and performance parameters and fatigue life curves corresponding to different materials of the charging gun wire; creating a bending model of copper wire and an inner sheath in the charging gun wire in finite element simulation software; creating a finite element simulation model of the charging gun wire in the finite element simulation software according to the bending model, the stress-strain curves and the performance parameters; performing a swing test of the charging gun wire, and correcting the performance parameters of the charging gun wire according to the test results; performing swing fatigue life simulation on the charging gun wire by using the corrected finite element simulation model, and generating a fatigue life curve; and correcting the simulation results according to the extracted fatigue life curve to generate a life prediction model. The application can accurately predict the swing strength and life of the charging gun wire, can shorten the research and development cycle, and can optimize the optimal parameters of the charging gun wire according to the design life, thereby reducing the material cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of charging piles, in particular to a life prediction method of a charging gun wire and a life prediction device of the charging gun wire BACKGROUND

[0002] In recent years, with the rapid development of key technologies of electric vehicles, electric vehicles have become very popular, and their annual sales have accounted for about 30% of the automobile industry. As a connecting medium for electric vehicles and charging equipment, the service life of the charging gun and the gun wire is crucial.

[0003] The charging gun wire is composed of an outer sheath, a filler, an inner sheath and a wire, and a cooling liquid pipeline exists in the liquid-cooled charging equipment gun wire. Once the sheath and the liquid cooling pipeline are damaged during use, safety accidents such as electric leakage will occur. Therefore, the charging gun wire needs to be subjected to a swing fatigue test at the beginning of design, and it is considered qualified if no damage occurs within a certain number of swings (for example, 20,000 times). If the swing fatigue life test is not passed, the design must be redesigned.

[0004] This way greatly delays the research and development cycle and increases the research and development cost. Moreover, the swing fatigue life test cannot quantify how many times the charging gun wire is damaged, which brings great difficulty to the redesign. SUMMARY

[0005] To solve the above technical problems, the first aspect embodiment of the present application provides a life prediction method of a charging gun wire.

[0006] The second aspect embodiment of the present application provides a life prediction device of a charging gun wire.

[0007] The technical solutions adopted by the present application are as follows:

[0008] The first aspect embodiment of the present application provides a life prediction method of a charging gun wire, comprising the following steps: performing tensile tests on different materials of the charging gun wire at different speeds by a universal material testing machine to extract corresponding stress-strain curves C1 and performance parameters of the different materials, and extracting fatigue life curves C2 of the different materials of the charging gun wire by a fatigue testing machine; creating a bending model of copper wires and inner sheaths in the charging gun wire in a finite element simulation software, and inversely deducing bending stiffness of the copper wires in the bending model through a bending test of the copper wires; creating a finite element simulation model of the charging gun wire in the finite element simulation software according to the bending model, the stress-strain curves C1 and the performance parameters; performing a swing test of the charging gun wire, correcting performance parameters of the charging gun wire in the finite element simulation model of the charging gun wire according to displacement curves and acceleration curves of the charging gun wire at multiple positions during the swing test; simulating swing fatigue life of the charging gun wire by using the corrected finite element simulation model of the charging gun wire and generating a fatigue life curve, correcting the fatigue life curve generated during the swing fatigue life simulation according to the fatigue life curves C2 extracted by the fatigue testing machine, to determine a fatigue life prediction model; and predicting fatigue life of the charging gun wire by using the fatigue life prediction model.

[0009] The fatigue life prediction method of the charging gun wire has the following additional technical features:

[0010] According to one embodiment of the present application, the performance parameters include: density, Poisson's ratio and elastic modulus.

[0011] According to one embodiment of the present application, the bending model adopts tetrahedral or hexahedral elements.

[0012] According to one embodiment of the present application, the finite element simulation model of the charging gun wire adopts hexahedral or tetrahedral elements.

[0013] The second aspect embodiment of the present application provides a life prediction device of a charging gun wire, comprising: an extraction module, the extraction module is used for respectively performing tensile tests on different materials of the charging gun wire at different rates through a universal material testing machine, so as to extract corresponding stress-strain curves C1 and performance parameters of different materials, and extract fatigue life curves C2 of different materials in the charging gun wire through a fatigue testing machine; a first creation module, the first creation module is used for creating a bending model of copper wires and inner sheaths in the charging gun wire in finite element simulation software, and inversely deducing bending stiffness of the copper wires in the bending model through a bending test of the copper wires; a second creation module, the second creation module is used for creating a finite element simulation model of the charging gun wire in the finite element simulation software according to the bending model, the stress-strain curves C1 and the performance parameters; a first correction module, the first correction module is used for performing a swing test of the charging gun wire, and correcting performance parameters of the charging gun wire in the finite element simulation model of the charging gun wire according to displacement curves and acceleration curves of the charging gun wire at a plurality of positions during the swing test; a second correction module, the second correction module is used for performing swing fatigue life simulation on the charging gun wire by using the corrected finite element simulation model of the charging gun wire, and generating a fatigue life curve, and correcting the fatigue life curve generated during the swing fatigue life simulation according to the fatigue life curves C2 extracted by the fatigue testing machine, so as to determine a fatigue life prediction model; and a prediction module, the prediction module is used for performing fatigue life prediction of the charging gun wire by using the fatigue fatigue life prediction model.

[0014] The life prediction device of the charging gun wire has the following additional technical features:

[0015] According to one embodiment of the present application, the performance parameters include: density, Poisson's ratio and elastic modulus.

[0016] According to one embodiment of the present application, the bending model adopts tetrahedral or hexahedral elements.

[0017] According to one embodiment of the present application, the finite element simulation model of the charging gun wire adopts hexahedral or tetrahedral elements.

[0018] The present application has the following beneficial effects:

[0019] The present application firstly realizes modeling of the bending model of the copper wires and the inner sheaths in the charging gun wire through finite element modeling, then realizes finite element simulation of the swing fatigue life of the gun wire through finite element modeling, and corrects the simulation results through tests, so as to realize accurate prediction of the swing strength and the life of the charging gun wire, which not only shortens the research and development cycle, but also optimizes the best parameters of the charging gun wire according to the designed life, and reduces the material cost. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a flow chart of a life prediction method of a charging gun line according to an embodiment of the present application;

[0021] Figure 2 is a schematic cross-sectional view of a charging gun line according to an embodiment of the present application;

[0022] Figure 3 is a block schematic diagram of a life prediction device of a charging gun line according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0024] Figure 1 is a flow chart of a life prediction method of a charging gun line according to an embodiment of the present application, as shown in Figure 1 , the method comprises the following steps:

[0025] S1, respectively, the different materials of the charging gun line are subjected to tensile tests at different rates to extract the stress-strain curves C1 and performance parameters corresponding to different materials, and the fatigue life curves C2 of different materials in the charging gun line are extracted.

[0026] The performance parameters include: density, Poisson's ratio, elastic modulus.

[0027] Specifically, as shown in Figure 2 , the charging gun line is composed of an outer sheath 1, a filler 2, an inner sheath 4, a wire 4, a ground wire 5, a cooling liquid pipe 6, a return pipe 7 and a reinforcing core 8, different parts are made of different materials, the outer sheath 1 is generally made of TPU (Thermoplastic Polyurethanes, thermoplastic polyurethane elastomer rubber) material, the filler 2 is generally made of PP (Polypropylene, polypropylene) material, the inner sheath 2 is generally made of XLPE (Crosslinked Polyethylene Cable, crosslinked polyethylene) material, the wire 4 and the ground wire 5 are generally made of copper wire, and the cooling liquid pipe 6 is generally made of PO (Propylene Oxide, propylene oxide) material.

[0028] The stress-strain curve C1 refers to a curve of stress of a material and an applied strain, and the shape of the curve reflects various deformation processes such as brittleness, plasticity, yield, and fracture of the material under external force. The stress-strain curve C1 and performance parameters of different materials can be extracted by performing tensile tests on different materials at different rates of 0.001, 0.1, 10, and 100 through a universal material testing machine. The stress-strain curve C1 can be directly extracted by using the universal material testing machine. The fatigue life curve C2 refers to a curve of the relationship between the fatigue life of a material and the number of fracture cycles under alternating stress. The fatigue life curve C2 of different materials in the charging gun wire can be directly extracted by using a universal material testing machine or a fatigue life testing machine.

[0029] S2, create a bending model of the copper wire and the inner sheath in the charging gun wire in the finite element simulation software, and inversely deduce the bending stiffness of the copper wire in the bending model through the bending test of the copper wire.

[0030] The bending model can use tetrahedral or hexahedral elements.

[0031] Specifically, a bending model of the copper wire (conductor and ground wire) and the inner sheath thereof in the charging gun wire is created in the finite element simulation software. The tetrahedral or hexahedral elements are used in the bending model. The copper wire and the corresponding inner sheath are connected in the form of shared nodes. The bending stiffness of the copper wire is inversely deduced through the bending test.

[0032] S3, create a finite element simulation model of the charging gun wire in the finite element simulation software according to the bending model, the stress-strain curve C1, and the performance parameters.

[0033] The finite element simulation model of the charging gun wire uses hexahedral or tetrahedral elements.

[0034] Specifically, when establishing the finite element simulation model of the charging gun wire, the bending model of the copper wire and the corresponding inner sheath is checked in S2. The nodes of the inner sheath, the filler, the liquid cooling pipe, and the outer sheath at adjacent positions are corresponded one by one. The contact pair or general contact is used. The material performance in the model uses the performance parameters and the stress-strain curve C1 measured in S1.

[0035] S4, perform a swing test of the charging gun wire, and correct the performance parameters of the charging gun wire in the finite element simulation model of the charging gun wire according to the displacement curve and the acceleration curve of the charging gun wire at multiple positions during the swing test.

[0036] Specifically, the swing test of the charging gun wire is performed. The swing test of the gun wire is compared with the simulation of the finite element simulation model in S3. The modulus and other performance parameters of each material in the finite element simulation model are corrected by comparing the displacement curve and the acceleration curve at multiple positions during the swing. The stress-strain cloud diagram of each position of the gun wire is generated.

[0037] S5. The finite element simulation model of the modified charging gun line is used to simulate the oscillating fatigue life of the charging gun line and generate the fatigue life curve. The fatigue life curve generated during the oscillating fatigue life simulation is corrected according to the fatigue life curve C2 extracted by the fatigue testing machine, so as to determine the fatigue life prediction model.

[0038] Specifically, after correcting the performance parameters of the charging gun line in the finite element simulation model of the charging gun line, the corrected finite element simulation model is used to perform oscillation fatigue life simulation of the charging gun line to generate a fatigue life curve. The fatigue life curve C2 extracted in step S1 of the simulation results is benchmarked, and the fatigue life curve output by the finite element simulation model is corrected according to the fatigue life curve C2 extracted in step S1. A fatigue life prediction model is generated based on the corrected finite element simulation model.

[0039] S6 uses a fatigue life prediction model to predict the fatigue life of the charging gun cable.

[0040] Specifically, the fatigue life prediction model mentioned above can be directly used to predict and optimize the life of the new charging cable from the initial design stage, without the need for repeated swing fatigue tests.

[0041] In summary, the charging gun wire life prediction method according to the embodiments of the present invention first models the bending model of the copper wire and inner sheath in the charging gun wire through finite element modeling, and then performs finite element simulation of the swing fatigue life of the charging gun wire through finite element modeling. The method is then corrected by experimental and simulation results, thereby achieving accurate prediction of the swing intensity and life of the charging gun wire. This not only shortens the research and development cycle, but also optimizes the best parameters of the charging gun wire according to the design life, reducing material costs.

[0042] Corresponding to the above-described method for predicting the lifespan of charging cables, this invention also proposes a device for predicting the lifespan of charging cables. Since the device embodiment of this invention corresponds to the method embodiment described above, details not disclosed in the device embodiment can be found in the method embodiment described above, and will not be repeated here.

[0043] Figure 3 This is a block diagram of a charging gun cable life prediction device according to an embodiment of the present invention, as shown below. Figure 3 As shown, the device includes: an extraction module 10, a first creation module 20, a second creation module 30, a first correction module 40, a second correction module 50, and a prediction module 60.

[0044] The extraction module 10 is used for performing tensile tests on different materials of the charging gun wire at different rates by a universal material testing machine to extract corresponding stress-strain curves C1 and performance parameters of different materials, and extracting fatigue life curves C2 of different materials in the charging gun wire by a fatigue testing machine; the first creation module 20 is used for creating a bending model of the copper wire and the inner sheath in the charging gun wire in a finite element simulation software, and inversely deducing the bending stiffness of the copper wire in the bending model through a bending test of the copper wire; the second creation module 30 is used for creating a finite element simulation model of the charging gun wire in the finite element simulation software according to the bending model, the stress-strain curves C1 and the performance parameters; the first correction module 40 is used for performing a swing test of the charging gun wire, and correcting the performance parameters of the charging gun wire in the finite element simulation model of the charging gun wire according to displacement curves and acceleration curves of the charging gun wire at a plurality of positions during the swing test; the second correction module 50 is used for performing swing fatigue life simulation on the charging gun wire by using the corrected finite element simulation model of the charging gun wire, and generating a fatigue life curve, and correcting the fatigue life curve generated during the swing fatigue life simulation according to the fatigue life curve C2 extracted by the fatigue testing machine to determine a fatigue life prediction model; and the prediction module 60 is used for predicting the life of the charging gun wire by using the fatigue life prediction model.

[0045] According to an embodiment of the present application, the performance parameters include: density, Poisson's ratio and elastic modulus.

[0046] According to an embodiment of the present application, the bending model adopts tetrahedral or hexahedral elements.

[0047] According to an embodiment of the present application, the finite element simulation model of the charging gun wire adopts hexahedral or tetrahedral elements.

[0048] In summary, according to the life prediction device of the charging gun wire of the embodiment of the present application, the modeling of the bending model of the copper wire and the inner sheath in the charging gun wire is realized through finite element modeling, the finite element simulation of the swing fatigue life of the gun wire is realized through finite element modeling, and the test and simulation results are corrected, so that the swing strength and the life of the charging gun wire can be accurately predicted, the research and development cycle can be shortened, the optimal parameters of the charging gun wire can be optimized according to the design life, and the material cost can be reduced.

[0049] In the description of the application, reference to "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" means that a particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment or example. Furthermore, the described specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. Moreover, the usage of the terms "first", "second" or "third" does not limit the quantity or order of the specific features, structures, materials or characteristics, but rather the term "first", "second" or "third" can be used to distinguish different features, structures, materials or characteristics, which can be combined in any suitable manner. Furthermore, the singular forms "a", "an" and "the" include plural references unless the context clearly dictates otherwise.

[0050] Furthermore, the terms "first", "second", or the like, merely denote different instances of a similar feature, structure, material or characteristic, without necessarily implying any relative importance or any particular order. Thus, a feature defined with "first" or "second" can implicitly or explicitly include at least one of the features. In the description of the application, the meaning of "a plurality" is at least two, for example two, three or four, unless otherwise specifically defined.

[0051] Any process or method descriptions or blocks in flow charts or otherwise described herein represent embodiments which can be managed as one or more modules, segments, or portions of code which include one or more steps for implementing specific logic functions or steps, and the terms in the specification have their ordinary technical and / or scientific meanings unless expressly defined otherwise. The embodiments of methods or processes described herein are preferably implemented as code (e.g., one or more modules) of one or more computer programs consistent with the performance of functions described herein, which would be written in a suitable computer readable program language and as one or more computer readable storage media storing such code.

[0052] The logic and / or steps represented in flow diagrams or otherwise described herein, for example, can be considered as a sequence of instructions to implement logic functions, and can be embodied in any computer-readable medium for use by an instruction execution system, apparatus, or device, such as a computer-based system, processor- containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this specification, a "computer-readable medium" can be any means that can contain, store, communicate, propagate or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium can be a machine-readable storage device (e.g., magnetic, optical or other) a machine-readable storage diskette (e.g., floppy, flexible or other), a machine-readable storage card (e.g., ROM, EEPROM, flash memory or other), a machine- readable storage tape (e.g., magnetic, optical or other), a machine-readable storage medium (e.g., a portable electronic device, a computer diskette, a computer memory, a broadcast transmission, or the like), or a machine-readable interface device (e.g., a wireless link, optical link or other). The computer-readable medium can also be, or be included in, a computer program product apparatus that tangibly embodies the programming of instructions. The instructions can be executable by a processor of the instruction execution system, apparatus, or device. In another embodiment, the logic and / or steps represented in flow diagrams or otherwise described herein can be considered as a sequence of logic elements, such as steps, functions, or the like, that can be embodied in any computer-readable medium for execution by an instruction execution system, apparatus, or device.

[0053] It should be understood that aspects of the application can be implemented in hardware, software, firmware or combinations thereof. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. As such, in some embodiments, the logic and / or steps represented in flow diagrams can be embodied in a computer-readable medium that includes instructions for execution by a processor. In another embodiment, the logic and / or steps represented in flow diagrams can be implemented in hardware, such as with any one or a combination of discrete logic circuitry, application specific integrated circuits (ASICs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), etc.

[0054] Those of skill in the art would understand that information and signals can be represented using any of a variety of technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that can be referenced throughout the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0055] In addition, each function unit in each embodiment of the present application can be integrated in one processing module, or each unit can be physically present separately, or two or more units can be integrated in one module. The integrated module can be realized in the form of hardware or in the form of a software function module. When the integrated module is realized in the form of a software function module and sold or used as an independent product, it can also be stored in a computer readable storage medium.

[0056] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method for predicting the lifetime of a charging gun cable, characterized in that, The method comprises the following steps: respectively, to extract the stress-strain curve C1 and the performance parameters corresponding to different materials, and to extract the fatigue life curve C2 of different materials in the charging gun wire through a fatigue testing machine; a bending model of the copper wire and the inner sheath in the charging gun wire is created in a finite element simulation software, and the bending stiffness of the copper wire in the bending model is back calculated through a bending test of the copper wire; a finite element simulation model of the charging gun wire is created in the finite element simulation software according to the bending model, the stress-strain curve C1 and the performance parameters; an oscillation test of the charging gun wire is performed, and the performance parameters of the charging gun wire in the finite element simulation model are corrected according to the displacement curve and the acceleration curve of the charging gun wire at multiple positions during the oscillation test; an oscillation fatigue life simulation of the charging gun wire is performed by using the corrected finite element simulation model of the charging gun wire, and a fatigue life curve is generated, and the fatigue life curve generated during the oscillation fatigue life simulation is corrected according to the fatigue life curve C2 extracted by the fatigue testing machine, so as to determine a fatigue life prediction model; the fatigue life prediction model is used to predict the fatigue life of the charging gun wire.

2. The life prediction method of a charging gun line according to claim 1, characterized by, The performance parameters include density, Poisson's ratio and elastic modulus.

3. The life prediction method of a charging gun line according to claim 1, characterized by, The bending model adopts tetrahedral or hexahedral elements.

4. The life prediction method of a charging gun line according to claim 1, characterized by, The finite element simulation model of the charging gun wire adopts hexahedral or tetrahedral elements.

5. A life prediction device for a charging gun cable, characterized by, It comprises: an extraction module, which is used to respectively perform a tensile test at different rates on different materials of the charging gun wire through a universal material testing machine, so as to extract the stress-strain curve C1 and the performance parameters corresponding to different materials, and to extract the fatigue life curve C2 of different materials in the charging gun wire through a fatigue testing machine; a first creation module, which is used to create a bending model of the copper wire and the inner sheath in the charging gun wire in a finite element simulation software, and to back calculate the bending stiffness of the copper wire in the bending model through a bending test of the copper wire; a second creation module, which is used to create a finite element simulation model of the charging gun wire in the finite element simulation software according to the bending model, the stress-strain curve C1 and the performance parameters; a first correction module, which is used to perform an oscillation test of the charging gun wire, and to correct the performance parameters of the charging gun wire in the finite element simulation model of the charging gun wire according to the displacement curve and the acceleration curve of the charging gun wire at multiple positions during the oscillation test; a second correction module, which is used to perform an oscillation fatigue life simulation of the charging gun wire by using the corrected finite element simulation model of the charging gun wire, to generate a fatigue life curve, and to correct the fatigue life curve generated during the oscillation fatigue life simulation according to the fatigue life curve C2 extracted by the fatigue testing machine, so as to determine a fatigue life prediction model; a prediction module, which is used to predict the fatigue life of the charging gun wire by using the fatigue life prediction model.

6. The life prediction device of the charging gun line according to claim 5, characterized by, The performance parameters include density, Poisson's ratio and elastic modulus.

7. The life prediction device of the charging gun line according to claim 5, characterized by, The bending model adopts tetrahedral or hexahedral elements. The finite element simulation model of the charging gun wire adopts hexahedral or tetrahedral elements.

8. The life prediction device of the charging gun line according to claim 5, characterized by, The finite element simulation model of the charging gun line adopts hexahedral or tetrahedral elements. The finite element simulation model of the charging gun line adopts hexahedral or tetrahedral elements.

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