A method for constructing a vehicle body distortion model, a train model construction method and system

Abstract

This invention discloses a method and system for constructing a vehicle body distortion model, a train model, and a system thereof. The method includes obtaining similarity factors for various design variables; establishing a full-size equivalent vehicle body model based on the stiffness equivalence principle; constructing a vehicle body distortion model based on the similarity factors of the various design variables and the required thickness or a preset thickness distortion coefficient; calculating the distortion coefficient corresponding to the dynamic response-time on the vehicle body distortion model based on the distortion relationship between the thickness distortion coefficient and the dynamic response-time; and correcting the dynamic response-time curve of the vehicle body distortion model based on the distortion coefficient corresponding to the dynamic response-time. This invention aims to correct the dynamic response of a vehicle body distortion model by determining the distortion coefficients of other dynamic responses through the relationship between the thickness distortion coefficient and the distortion coefficients of other dynamic responses, thereby correcting the dynamic response of the vehicle body distortion model and reducing the impact of thickness distortion on the model's dynamic response.

Description

Technical Field

[0001] This invention belongs to the field of train equivalent model construction technology, specifically involving a method for constructing a car body distortion model with thickness distortion, a train model construction method and system. Background Technology

[0002] With the continuous increase in train speeds, train collisions can cause significant casualties and property damage. Therefore, conducting research on train crashworthiness is crucial for improving the passive safety protection capabilities of trains. Testing is the most direct and effective research method for investigating the mechanical response and behavior of trains during collisions, and can be divided into full-vehicle testing and scaled-down testing. However, full-vehicle testing is costly, time-consuming, and has poor repeatability; while scaled-down testing is low-cost and efficient, and can realistically reproduce the dynamic response characteristics of trains under complex impact conditions, making it an effective and reliable method for studying train crashworthiness.

[0003] Currently, Yao Shuguang and others have proposed an invention patent for "a method for constructing an equivalent scale model of a train and an equivalent scale model of a train". This technology obtains the scale factor of each dynamic parameter of the equivalent scale model of a train compared to a full-size train, and then constructs the head car and intermediate car of the equivalent scale model of the train based on the scale factor of the dynamic parameters. The small-scale equivalent model cars of the train are connected by an energy absorption device.

[0004] Xu Ping et al. proposed an invention patent for "a method for constructing a head car scaled-down model based on force and stiffness equivalence and a head car scaled-down model". This technology obtains the similarity factors of various dynamic parameters of the head car scaled-down model compared with the full-size train, and then divides the full-size train head car into a deformation energy absorption zone and a non-deformation zone according to the deformation energy absorption characteristics. The deformation energy absorption zone of the head car scaled-down model is designed according to the deformation energy absorption characteristic curve and the size similarity factor, and the non-deformation zone of the head car scaled-down model is designed according to the stiffness similarity factor and the size similarity factor.

[0005] However, both of the above technologies still have some shortcomings. Specifically, directly constructing an equivalent scaled-down model based on a full-size train is difficult due to the large and complex structure of the train prototype. Furthermore, the car body is a thin-walled welded aluminum alloy structure, and the similarity factor for thickness is the same as that for length and width (the actual thickness of the train body plate is usually between 10mm and 20mm; if the geometric similarity ratio is 8, then the thickness of the car body plate in the equivalent scaled-down model is 1.25mm to 2.5mm). Therefore, the thickness of the equivalent scaled-down model is too small to be processed. Thus, in order to meet the needs of practical applications, this invention aims to study how to eliminate / reduce the influence of thickness distortion on the dynamic response of the train model and correct the dynamic response under distortion conditions. Summary of the Invention

[0006] This invention addresses the problem of distorted dynamic response in equivalent train models under thickness distortion conditions in practical engineering applications. It provides a method and system for constructing a car body distortion model and a train model, both with thickness distortion. Specifically, the technical solution of this invention reveals that if the car body thickness is not proportionally reduced to its length, width, and height, a car body thickness distortion condition exists (a thickness distortion coefficient exists). This leads to model distortion, specifically causing distortion in the velocity-time, displacement-time, and acceleration-time curves, which are not entirely equivalent to the actual dynamic response of the train. Therefore, this invention aims to correct the dynamic response of the distorted model by determining the distortion coefficients of other dynamic responses through the relationship between the thickness distortion coefficient and the distortion coefficients of other dynamic responses, thereby correcting the dynamic response of the distorted model and reducing the distortion impact of thickness distortion on the model's dynamic response.

[0007] On the one hand, the present invention provides a method for constructing a vehicle body distortion model, which includes the following steps:

[0008] The similarity factors of each design variable in the equivalent vehicle body are obtained based on the principle of similarity. The design variables generally include: length, force, time, velocity, acceleration, mass, stiffness, and energy.

[0009] Based on the principle of stiffness equivalence, an equivalent full-size train body model was established, which is equivalent to the full-size prototype train body described above.

[0010] Based on the similarity factor of the design variables and the required thickness or preset thickness distortion coefficient, a vehicle body distortion model is constructed on the basis of the full-size vehicle body equivalent model.

[0011] Specifically, for design variables other than vehicle body thickness on the vehicle body distortion model, scaling is performed based on the corresponding similarity factor on the full-size vehicle body equivalent model; the vehicle body thickness of the vehicle body distortion model is set according to a preset thickness distortion coefficient or according to a preset thickness value. The distortion coefficient is the ratio of the thickness on the vehicle body distortion model to the thickness scaled on the full-size vehicle body equivalent model based on the similarity factor (the thickness of the reference model).

[0012] Obtain a set of thickness distortion coefficients and dynamic response-time distortion relationships corresponding to the prototype train body, and calculate the distortion coefficients corresponding to dynamic response-time on the body distortion model based on the distortion relationships;

[0013] The dynamic response-time curve of the vehicle body distortion model is corrected based on the distortion coefficient corresponding to the dynamic response-time, thus completing the construction of the vehicle body distortion model.

[0014] This invention addresses this issue by using a similarity factor to scale other design variables besides thickness; for thickness, it sets the scaling factor based on the thickness distortion coefficient or the required thickness, thus constructing a vehicle body distortion model with thickness distortion. However, the constructed vehicle body distortion model suffers from distorted dynamic response due to the thickness distortion. Therefore, this invention proposes a relationship between the thickness distortion coefficient and the dynamic response-time distortion, using the thickness distortion coefficient to determine the distortion coefficient corresponding to the dynamic response-time, thereby correcting the dynamic response of the vehicle body distortion model. It should be understood that the vehicle body distortion model obtained after correcting the dynamic response-time curve proposed in this invention is the truly accurate vehicle body distortion model.

[0015] Further optionally, each type of prototype train body structure corresponds to a set of the aforementioned thickness distortion coefficients and the distortion relationship between dynamic response and time;

[0016] The process for constructing the relationship between the thickness distortion coefficient and the dynamic response-time distortion for any type of prototype train body structure is as follows:

[0017] A: Construct the car body baseline model and the car body distortion model. That is, after obtaining the full-size car body equivalent model corresponding to the full-size prototype train car body, construct a series of car body distortion models and record the thickness distortion coefficient corresponding to each car body distortion model, as well as the car body baseline model for constructing the full-size car body equivalent model.

[0018] Among them, all design variables except thickness on each vehicle body distortion model and all design variables including thickness on the vehicle body reference model are scaled on the full-size vehicle body equivalent model according to the corresponding similarity factor, and the similarity factor values ​​corresponding to the same type of design variables are the same between different models.

[0019] B: Perform collision simulations / experiments on each vehicle body distortion model and vehicle body baseline model to obtain the dynamic response-time curves for each model.

[0020] C: Compare the dynamic response-time curve of each vehicle body distortion model with the dynamic response-time curve of the vehicle body reference model to obtain a set of dynamic response prediction coefficients and time prediction coefficients corresponding to each vehicle body distortion model;

[0021] Wherein, the dynamic response prediction coefficient and the time prediction coefficient are the ratio of the dynamic response of a set of reference points on the vehicle body distortion model and the vehicle body reference model on their respective dynamic response-time curves, and the ratio of time;

[0022] D: Based on several sets of dynamic response prediction coefficients, time prediction coefficients, and thickness distortion coefficients corresponding to the series of vehicle body distortion models, a relationship between the thickness distortion coefficient and the dynamic response prediction coefficient and the time prediction coefficient is fitted. The relationship represents the distortion relationship between the thickness distortion coefficient and the dynamic response-time.

[0023] It should be understood that the fitted distortion relationship is only applicable to one vehicle body prototype, but it is applicable to all vehicle body distortion models based on this vehicle body prototype. This is because the fitted distortion relationship is based on the dynamic response-time curves of the vehicle body reference model and the vehicle body distortion model. The dynamic response of the vehicle body reference model reflects the dynamic response of the vehicle body prototype. Different vehicle body prototypes have different dynamic responses. Therefore, the fitted relationship is only applicable to one vehicle body prototype.

[0024] Further optionally, the relationship between the thickness distortion coefficient and the dynamic response and time is expressed as:

[0025]

[0026] In the formula, Represents the prediction coefficients of the dynamic response of type j. Indicates the time prediction coefficient. Indicates the thickness distortion coefficient. A set of coefficients representing the relationship between the dynamic response prediction coefficient and the thickness distortion coefficient. The coefficients represent the relationship between the time prediction coefficient and the thickness distortion coefficient. It should be understood that both sets of coefficients are obtained through data fitting.

[0027] Further optionally, the type of the dynamic response includes: displacement, acceleration, and velocity.

[0028] Further optionally, the distortion coefficient corresponding to the dynamic response-time includes the dynamic response prediction coefficient and the time prediction coefficient;

[0029] The relationship between the thickness distortion coefficient and the distortion of the dynamic response-time is the relationship between the thickness distortion coefficient and the dynamic response prediction coefficient and the time prediction coefficient.

[0030] The dynamic response-time curve of the vehicle body distortion model, which is corrected based on the distortion coefficient corresponding to the dynamic response-time, includes at least the following:

[0031] The corrected dynamic response on the dynamic response-time curve is calculated using the following formula: ,in, The corrected dynamic response, The dynamic response of the vehicle body distortion model. This represents the prediction coefficient for the corresponding type j dynamic response.

[0032] It should be understood that in some implementations, the time prediction coefficient is ignored and no time correction is applied; in other implementations, the corrected time on the dynamic response-time curve is calculated using the following formula: ,in, The corrected time. The time on the dynamic response-time curve of the vehicle body distortion model is represented by the time parameter. This represents the time prediction coefficient. In other implementations, the time prediction coefficients for the displacement-time curve, acceleration-time curve, and velocity-time curve are calculated, and the average of the three time prediction coefficients is used to correct the displacement-time curve, acceleration-time curve, and velocity-time curve.

[0033] Further, optionally, the similarity factors for each design variable are as follows:

[0034] , , , , , , ,

[0035] In the formula, For size similarity factor, , , , , , , , These are the length similarity factor, force similarity factor, time similarity factor, velocity similarity factor, acceleration similarity factor, mass similarity factor, stiffness similarity factor, and energy similarity factor, respectively.

[0036] Secondly, the present invention provides a train model construction method based on the aforementioned vehicle body distortion model construction method, comprising:

[0037] The full-size prototype train was structurally disassembled into the car body and energy absorption device.

[0038] Construct the car body distortion model in the train model according to the described car body distortion model construction method;

[0039] The energy absorption device in the train model is constructed based on the similarity factor and energy absorption characteristic curve.

[0040] Thirdly, the present invention provides a train model based on the aforementioned vehicle body distortion model construction method, which includes a lead car and an intermediate car;

[0041] The lead vehicle includes a lead vehicle body and a lead vehicle energy absorption device; the intermediate vehicle includes an intermediate vehicle body and an intermediate vehicle energy absorption device; the lead vehicle body and the intermediate vehicle body are both constructed with a vehicle body distortion model according to the vehicle body distortion model construction method.

[0042] Fourthly, the present invention provides a system based on the vehicle body distortion model construction method, comprising:

[0043] The similarity factor acquisition module is used to obtain the similarity factors of each design variable in the vehicle body equivalent based on the similarity principle;

[0044] The full-size car body equivalent model construction module is used to establish a full-size car body equivalent model that is equivalent to the full-size prototype train car body based on the stiffness equivalence principle;

[0045] The vehicle body distortion model construction module is used to construct a vehicle body distortion model based on the similarity factor of the design variables and the required thickness or preset thickness distortion coefficient, on the basis of the full-size vehicle body equivalent model.

[0046] Specifically, for design variables other than vehicle body thickness on the vehicle body distortion model, the model is scaled based on the corresponding similarity factor on the basis of the full-size vehicle body equivalent model; the vehicle body thickness of the vehicle body distortion model is set according to the preset thickness distortion coefficient or according to the preset thickness value.

[0047] The calculation module is used to obtain a set of thickness distortion coefficients and dynamic response-time distortion relationships corresponding to the prototype train body, and calculate the distortion coefficients corresponding to the dynamic response-time on the body distortion model based on the distortion relationships.

[0048] The correction module is used to correct the dynamic response-time curve of the vehicle body distortion model based on the distortion coefficient corresponding to the dynamic response-time, thereby completing the construction of the vehicle body distortion model.

[0049] Fifthly, the present invention provides a system based on the train model construction method, comprising:

[0050] The decomposition module is used to structurally decompose the full-size prototype train into the car body and energy absorption device.

[0051] The vehicle body distortion model construction module is used to construct the vehicle body distortion model in the train model;

[0052] The energy absorption device construction module is used to construct energy absorption devices in train models based on similarity factors and energy absorption characteristic curves.

[0053] The vehicle body distortion model construction module includes:

[0054] The similarity factor acquisition module is used to obtain the similarity factors of each design variable in the vehicle body equivalent based on the similarity principle;

[0055] The full-size car body equivalent model construction module is used to establish a full-size car body equivalent model that is equivalent to the full-size prototype train car body based on the stiffness equivalence principle;

[0056] The vehicle body distortion model construction module is used to construct a vehicle body distortion model based on the similarity factor of the design variables and the required thickness or preset thickness distortion coefficient, on the basis of the full-size vehicle body equivalent model.

[0057] Specifically, for design variables other than vehicle body thickness on the vehicle body distortion model, the model is scaled based on the corresponding similarity factor on the basis of the full-size vehicle body equivalent model; the vehicle body thickness of the vehicle body distortion model is set according to the preset thickness distortion coefficient or according to the preset thickness value.

[0058] The calculation module is used to obtain a set of thickness distortion coefficients and dynamic response-time distortion relationships corresponding to the prototype train body, and calculate the distortion coefficients corresponding to the dynamic response-time on the body distortion model based on the distortion relationships.

[0059] The correction module is used to correct the dynamic response-time curve of the vehicle body distortion model based on the distortion coefficient corresponding to the dynamic response-time, thereby completing the construction of the vehicle body distortion model.

[0060] Beneficial effects

[0061] 1. This invention reveals that if the vehicle body thickness is not proportionally reduced in length, width, and height, a vehicle body thickness distortion condition exists (a thickness distortion coefficient exists). This leads to model distortion, specifically causing distortion in the velocity-time, displacement-time, and acceleration-time curves, which are not entirely equivalent to the actual dynamic response of the train. However, in actual operating conditions, it is difficult to guarantee thickness equivalence, and proportionally reducing the thickness is also difficult to meet practical requirements. Therefore, vehicle body thickness distortion conditions are becoming increasingly common and increasingly difficult to avoid. To address / reduce the impact of this distortion, this invention provides a vehicle body distortion model construction method. This method determines the distortion coefficients of other dynamic responses by studying the relationship between the thickness distortion coefficient and the distortion coefficients of other dynamic responses, thereby correcting the dynamic response of the distorted model and reducing the distortion effect of thickness distortion on the model's dynamic response.

[0062] 2. In constructing the vehicle body distortion model, this invention does not directly scale the full-size prototype train body based on a similarity factor. Instead, it first constructs a full-size equivalent model based on the full-size prototype train body, and then constructs the vehicle body distortion model based on the equivalent model. Firstly, when using the full-size equivalent model as an intermediate transition, this invention constructs the full-size equivalent model based on the principle of stiffness equivalence. Therefore, while satisfying stiffness and mass equivalence, it does not need to use the same materials as the prototype to achieve the same impact performance between the full-size equivalent model and the full-size prototype train body (when using different materials, equivalence is ensured by adjusting the thickness of each vehicle body unit structure, without affecting the overall shape and size approximation). Thus, the materials of the vehicle body distortion model and the prototype train body can also be different, resulting in fewer constraints and better adaptability to the complex structure and diverse materials of actual trains. Secondly, constructing the vehicle body distortion model based on the full-size equivalent model is less difficult and easier to implement. Attached Figure Description

[0063] Figure 1 These are the prototype and the equivalent model of the full-size vehicle body, where 1(a) is the prototype and 1(b) is the equivalent model of the full-size vehicle body.

[0064] Figure 2 This is a schematic diagram of the longitudinal dynamic response of the vehicle body reference model, where 2(a) is the displacement-time curve, 2(b) is the velocity-time curve, and 2(c) is the deceleration-time curve.

[0065] Figure 3 These are schematic diagrams of the longitudinal dynamic response of the vehicle body reference model, distortion model, and distortion correction model. Among them, 3(a) is the displacement-time curve, 3(b) is the velocity-time curve, and 3(c) is the deceleration-time curve.

[0066] Figure 4 This is a schematic diagram of the division of the intermediate car body unit of the train. Among them, 4(a) is a schematic diagram of the full-size prototype intermediate car body, 4(b) is a schematic diagram of the equivalent model of the full-size intermediate car body, and 4(c) is a scaled-down model of the car body. Detailed Implementation

[0067] This invention aims to solve the problem of dynamic response distortion caused by thickness distortion in vehicle body distortion models. By determining the distortion coefficients of other dynamic responses through the relationship between the thickness distortion coefficient and these coefficients, the dynamic response of the distortion model can be corrected, reducing the impact of thickness distortion on the model's dynamic response. This results in a vehicle body distortion model with reduced thickness distortion. Consequently, vehicle body models / train models constructed using this invention do not require excessive concern about thickness distortion, effectively reducing the likelihood of insufficient thickness in existing practical engineering models that cannot be manufactured. The invention will be further illustrated below with reference to embodiments.

[0068] Example 1:

[0069] First, a simple analysis is performed on the relationship between thickness distortion and other dynamic responses in the vehicle body distortion model:

[0070] In this technical field, similarity factors for various physical quantities in a vehicle collision can be derived based on similarity criteria. Specifically, based on the conditions of complete similarity, the geometric dimensions of the train model and the prototype are completely similar, the materials are completely identical, and the similarity criteria for various physical quantities of the train model are analyzed according to the longitudinal motion equations of the train system. Under the condition of consistent boundary conditions, the design criteria for the train model are shown in Table 1.

[0071] Table 1

[0072]

[0073] in, For size similarity factor, , , , , , , These are force similarity factor, time similarity factor, velocity similarity factor, acceleration similarity factor, mass similarity factor, stiffness similarity factor, and energy similarity factor, respectively.

[0074] A model completely similar to a full-size vehicle body equivalent model is used as the baseline model. Models that differ from the baseline model only in thickness distortion are called distorted models. When a model exhibits thickness distortion, the thickness distortion term... Thickness distortion term is provided , where subscript Let these represent the distortion model and the baseline model, respectively; then the thickness distortion coefficient... Defined by the following formula:

[0075] (1)

[0076] Thickness distortion coefficient This reflects the degree of model distortion, and the design conditions for the distorted model should then follow:

[0077]

[0078]

[0079]

[0080] (2)

[0081] According to the similarity theorem, the dependent variable A term can be represented as an independent variable. The functional relationship of the terms can be expressed using a product relationship. The term is a commonly used formula in dimensional analysis. Let:

[0082] (3)

[0083] Define prediction coefficients From equations (1)-(3), we can obtain:

[0084] (4)

[0085] Clearly, the prediction coefficient is a function of the distortion coefficient. Assume the independent variable... Item for Due to change Item for .

[0086] In the above formula, 1-n represents the presence of n dimensionless units. Number, assumption For self-change item, For dependent variables Term. A is an undetermined coefficient, and a, b, ..., z are undetermined power exponents. Under certain conditions, the structural response is also deterministic; characterizing these deterministic conditions... The term is called the independent variable, which characterizes the structural response. All terms are functions of these independent variables and are called strain terms.

[0087] Taking a single variable as an example, the acceleration prediction coefficient is defined. ,and and The expression only in The above are different, therefore the acceleration prediction coefficient Distortion coefficient The function.

[0088] Based on the above principles, this embodiment provides a method for constructing a vehicle body distortion model, which includes the following steps:

[0089] Step 1: Obtain the similarity factors of each design variable between the train model and the full-size prototype train. See Table 1 for details.

[0090] Step 2: Based on the principle of stiffness equivalence, establish an equivalent full-size train body model that is equivalent to the full-size prototype train body. Taking the intermediate car body as an example, in this embodiment, the intermediate car body of the full-size prototype train is divided into... Each vehicle body unit, such as Figure 4 As shown in (a), an equivalent model of the full-size intermediate car body with the same impact characteristics as the intermediate car body on the full-size prototype train is established using the stiffness equivalence method, such as... Figure 4 As shown in (b); finally, based on the full-size equivalent model of the intermediate vehicle body, a distortion model of the intermediate vehicle body is established using the complete similarity method, as follows: Figure 4 As shown in (c).

[0091] Among them, for Figure 4 (a) shows the intermediate car on the full-size prototype train, which divides the car body into... There are several car body units, and the mass of each car body unit is as follows: , ... The structural stiffness of each car body unit is as follows: , ... An equivalent model of a full-size intermediate car body with a relatively simple structure and dimensions basically the same as the intermediate car body of a full-size train was established. The equivalent model of the full-size intermediate car body was further divided into... There are several car body units, and the mass of each car body unit is as follows: , ... The structural stiffness of each car body unit is as follows: , ... At the same location on the car body, the full-size intermediate car body and its equivalent model have the same number of car body elements. Furthermore, by adjusting the structure of each car body element in the equivalent model, the corresponding element stiffness and element mass of the full-size intermediate car body and its equivalent model are approximately equal. At this point, the stiffness characteristic curves of the equivalent model and the prototype intermediate car body have approximately equivalent relationships. When the car body undergoes small deformations within its elastic range, the load-bearing characteristics of the equivalent model and the prototype intermediate car body are the same.

[0092] For example, in this embodiment, the external dimensions of the full-size intermediate car body equivalent model are approximately equal to those of the prototype train intermediate car body, with a length, width, and height of 25000mm, 3360mm, and 2950mm respectively. Figure 1 As shown, the equivalent model of the full-size intermediate vehicle body has the same mass as the prototype intermediate vehicle body, which is 27,000 kg. In this embodiment, the ANSYS Workbench static analysis module is used to verify the deformation of the equivalent model of the full-size intermediate vehicle body and the prototype intermediate vehicle body, as well as the overall stiffness of the vehicle body.

[0093] In other feasible embodiments, the present invention does not restrict the specific process of establishing a full-size equivalent model of the full-size prototype train body based on the stiffness equivalence principle.

[0094] Step 3: Based on the similarity factor of the design variables and the required thickness or a preset thickness distortion coefficient, construct a vehicle body distortion model on the basis of the full-size vehicle body equivalent model. Specifically, for design variables other than the vehicle body thickness on the vehicle body distortion model, scale the full-size vehicle body equivalent model according to the corresponding similarity factor; set the vehicle body thickness of the vehicle body distortion model according to the preset thickness distortion coefficient or a preset thickness value.

[0095] It should be understood that the required vehicle body thickness may vary in actual engineering needs. A feasible approach is to directly set the required thickness or to set a thickness distortion coefficient. The distortion coefficient is the ratio of the thickness on the distorted vehicle body model to the thickness scaled onto the full-size equivalent vehicle body model based on a similarity factor (the thickness of the baseline model).

[0096] Therefore, the constructed vehicle body distortion model is as follows: except for the vehicle body thickness, other parameters are scaled down according to a set similarity factor. In this embodiment, a scale similarity factor of 1:8 is used for model scaling. For example, when the length, width, height and thickness of the vehicle body are all scaled down to 1:8, the corresponding length, width and height are 3125mm, 420mm and 369mm respectively.

[0097] Step 4: Obtain a set of thickness distortion coefficients and dynamic response-time distortion relationships corresponding to the prototype train body, and calculate the distortion coefficients corresponding to the dynamic response-time on the body distortion model based on the distortion relationships.

[0098] Each type of prototype train body structure corresponds to a set of thickness distortion coefficients and dynamic response-time distortion relationships; the process of constructing the thickness distortion coefficients and dynamic response-time distortion relationships for any type of prototype train body structure is as follows:

[0099] A: Constructing the car body baseline model and car body distortion model involves obtaining the full-size equivalent model of the full-size prototype train car body, constructing a series of car body distortion models, and recording the thickness distortion coefficient for each distortion model, as well as the car body baseline model for constructing the full-size equivalent model. All design variables on each car body distortion model except for thickness, and all design variables on the car body baseline model including thickness, are scaled on the full-size equivalent model according to the corresponding similarity factor. Furthermore, the similarity factor values ​​for the same type of design variables are the same across different models.

[0100] In this embodiment, a similar reference model is established at a 1:8 scale based on a full-size equivalent vehicle body model (the length, width, height and thickness of the vehicle body are all reduced to 1:8). On this basis, a series of thickness distortion models are established. The length, width and height of the reference model and the distortion model are 3125mm, 420mm and 369mm, respectively. A series of thicknesses are set as shown in Table 2, and the corresponding thickness distortion coefficients are calculated.

[0101] Table 2

[0102]

[0103] B: Perform collision simulations / experiments on each vehicle body distortion model and vehicle body baseline model to obtain the dynamic response-time curves for each model.

[0104] C: By comparing the dynamic response-time curve of each vehicle body distortion model with the dynamic response-time curve of the vehicle body reference model, a set of dynamic response prediction coefficients and time prediction coefficients corresponding to each vehicle body distortion model are obtained. The dynamic response prediction coefficients and time prediction coefficients are the ratios of the dynamic responses of a set of reference points on the respective dynamic response-time curves of the vehicle body distortion model and the vehicle body reference model, and the ratios of the times.

[0105] In this embodiment, displacement, velocity, and acceleration are selected as the main comparison parameters to verify the effectiveness of the benchmark model. Figure 2 As shown, the curves match well. The geometric dimensions and distortion coefficients of the baseline model and the distortion model of the vehicle body are shown in Table 2.

[0106] D: Based on several sets of dynamic response prediction coefficients, time prediction coefficients, and thickness distortion coefficients corresponding to the series of vehicle body distortion models, a relationship between the thickness distortion coefficient and the dynamic response prediction coefficient and the time prediction coefficient is fitted. The relationship represents the distortion relationship between the thickness distortion coefficient and the dynamic response-time.

[0107] Taking the displacement-time history curve as an example, the characteristic points of the vehicle body reference model curve are selected. (Take the point of maximum displacement), and assume the vehicle body reference model is at... The coordinates of the point are Extract the feature points corresponding to the vehicle body distortion model. Assume the vehicle body distortion model is in The coordinates of the point are Time prediction coefficient and displacement prediction coefficient The displacement-time history curves of each distortion model in Table 2 were calculated, and the resulting prediction coefficients are shown in Table 3. It should be understood that in other feasible embodiments, the selection of feature points can use other criteria, and this invention does not impose specific limitations on this.

[0108] Table 3

[0109]

[0110] By fitting the data in Table 3, we can obtain the functional relationships between the displacement prediction coefficient and the distortion coefficient, and the functional relationships between the time prediction coefficient and the distortion coefficient:

[0111] (5)

[0112] Similarly, the velocity prediction coefficient, acceleration prediction coefficient, and distortion coefficient can be obtained. The functional relationship, where the velocity prediction coefficient function and time prediction coefficient function as follows:

[0113] (6)

[0114] Acceleration prediction coefficient function and time prediction coefficient function as follows:

[0115] (7)

[0116] Based on the above relationship, by substituting the thickness distortion coefficient into the corresponding formula, we can obtain the prediction coefficient corresponding to the dynamic response-time, i.e., the distortion coefficient.

[0117] Step 5: Correct the dynamic response-time curve of the vehicle body distortion model based on the distortion coefficient corresponding to the dynamic response-time described in Step 4.

[0118] Using the vehicle body baseline model and distortion model Modal 3 ( Taking a model with a thickness of 4.968 mm as an example, the effectiveness of the correction method is verified. The distortion coefficients of the Modal 3 distortion model are shown. ,Will Substituting into equations (5) to (7), the corresponding prediction coefficients are obtained. The definition of the displacement prediction coefficient is as follows: Therefore, the displacement of the distortion correction model is Similarly, the velocity and acceleration values ​​of the distortion correction model can be obtained. That is, the horizontal and vertical axes of the distortion model are scaled according to the corresponding prediction coefficients to obtain the distortion correction model. The displacement, velocity, and acceleration response comparison curves are shown below. Figure 3 As shown. The results have some errors, but they are within acceptable limits. The thickness distortion correction method is feasible and can accurately predict the dynamic response of the prototype.

[0119] Example 2:

[0120] This embodiment provides a train model construction method based on the aforementioned vehicle body distortion model construction method, which includes:

[0121] Step S1. Decompose the full-size prototype train into its structure, dividing it into the car body and energy absorption device.

[0122] The response characteristics of different structural parts differ during a train collision. The collision characteristics of an energy-absorbing structure are reflected by compression, impact force, and absorbed energy; while in the design of impact-resistant trains, in order to maximize the passive safety protection of occupants, the car body structure only undergoes small deformations within the elastic range during a collision, and its collision characteristics are reflected in the collision deceleration response of the car body.

[0123] Taking the lead car as an example, the lead car includes the car body and the energy absorption device. The energy absorption device of the lead car includes the buffer, crush tube, main energy absorption device, etc.

[0124] Taking the intermediate car as an example, its energy-absorbing device consists of a buffer and a crushing tube. The equivalent scaled-down design of the energy-absorbing device includes two types of design parameters: length and force. The horizontal and vertical coordinate parameters of the energy-absorbing characteristic curve of the intermediate car buffer of the full-size train are multiplied by the length similarity factor. Force similarity factor The energy absorption characteristic curve of the equivalent compressed buffer can be obtained, and the energy absorbed when fully compressed can be obtained by integrating the energy absorption characteristic curve. The compression plateau force and compressible stroke of the intermediate car crush tube of the full-size prototype train are multiplied by the force similarity factor. Length similarity factor The compression plateau force and compressible stroke of the equivalent shrink-die crushing tube are obtained. Finally, the energy absorption characteristic curve of the equivalent shrink-die energy absorption device is obtained, that is, the compressible stroke and maximum energy absorption of the equivalent shrink-die buffer are 8.75mm and 22.66J, respectively, and the compression plateau force and compressible stroke of the crushing tube are 24kN and 45.63mm, respectively, and the design is carried out accordingly.

[0125] It should be noted that this invention does not restrict how the energy absorption device is designed; any corresponding existing technology can be used based on the similarity factor and energy absorption characteristic curve.

[0126] Step S2. Construct the car body distortion model in the train model according to steps 1-5; and construct the energy absorption device in the train model based on the similarity factor and energy absorption characteristic curve. The construction process of the car body distortion model can be referred to the detailed description in the foregoing embodiments. The construction of the energy absorption device can refer to existing technologies.

[0127] Example 3:

[0128] This invention provides a train model based on the aforementioned vehicle body distortion model construction method, which includes a lead car and an intermediate car;

[0129] The lead vehicle includes a lead vehicle body and a lead vehicle energy absorption device; the intermediate vehicle includes an intermediate vehicle body and an intermediate vehicle energy absorption device; the lead vehicle body and the intermediate vehicle body are both constructed with a vehicle body distortion model according to steps 1-5.

[0130] The specific implementation process can be found in the details of Embodiments 1 and 2.

[0131] Example 4:

[0132] This embodiment provides a system based on the vehicle body distortion model construction method, which includes: a similarity factor acquisition module, a full-size vehicle body equivalent model construction module, a vehicle body distortion model construction module, a calculation module, and a correction module.

[0133] The system includes the following modules: a similarity factor acquisition module for acquiring similarity factors of various design variables in the equivalent car body based on similarity principles; a full-size equivalent car body model construction module for establishing a full-size equivalent car body model based on stiffness equivalence principles; a car body distortion model construction module for constructing a car body distortion model based on the full-size equivalent car body model using the similarity factors of the various design variables and the required thickness or a preset thickness distortion coefficient; a calculation module for acquiring a set of the thickness distortion coefficients and the distortion relationship between dynamic response and time corresponding to the prototype train body, and calculating the distortion coefficients corresponding to the dynamic response and time on the car body distortion model based on the distortion relationship; and a correction module for correcting the dynamic response and time curve of the car body distortion model based on the distortion coefficients corresponding to the dynamic response and time, thus completing the construction of the car body distortion model.

[0134] Specifically, for design variables other than vehicle body thickness on the vehicle body distortion model, the model is scaled based on the corresponding similarity factor on the basis of the full-size equivalent vehicle body model; the vehicle body thickness of the vehicle body distortion model is set according to a preset thickness distortion coefficient or according to a preset thickness value.

[0135] Example 5:

[0136] This embodiment provides a system based on the train model construction method, which includes: a decomposition module, a car body distortion model construction module, and an energy absorption device construction module.

[0137] The decomposition module is used to structurally decompose the full-size prototype train into a car body and an energy-absorbing device; the car body distortion model construction module is used to construct the car body distortion model in the train model; and the energy-absorbing device construction module is used to construct the energy-absorbing device in the train model based on similarity factors and energy absorption characteristic curves.

[0138] The vehicle body distortion model construction module includes: a similarity factor acquisition module, a full-size vehicle body equivalent model construction module, a vehicle body distortion model construction module, a calculation module, and a correction module.

[0139] The similarity factor acquisition module is used to acquire the similarity factors of each design variable in the car body equivalence based on the similarity principle; the full-size car body equivalent model construction module is used to establish a full-size car body equivalent model that is equivalent to the full-size prototype train car body based on the stiffness equivalence principle; the car body distortion model construction module is used to construct a car body distortion model based on the similarity factors of each design variable and the required thickness or preset thickness distortion coefficient; the calculation module is used to acquire a set of the thickness distortion coefficients and the distortion relationship between dynamic response and time corresponding to the prototype train car body, and calculate the distortion coefficient corresponding to the dynamic response and time on the car body distortion model based on the distortion relationship; the correction module is used to correct the dynamic response and time curve of the car body distortion model based on the distortion coefficient corresponding to the dynamic response and time, and complete the construction of the car body distortion model.

[0140] Specifically, for design variables other than vehicle body thickness on the vehicle body distortion model, the model is scaled based on the corresponding similarity factor on the basis of the full-size equivalent vehicle body model; the vehicle body thickness of the vehicle body distortion model is set according to a preset thickness distortion coefficient or according to a preset thickness value.

[0141] The implementation process of each module in Examples 4 and 5 is described in the above method and will not be repeated here. It should be understood that the above division of functional modules is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the integrated units described above can be implemented in hardware or as software functional units.

[0142] It should be emphasized that the examples described in this invention are illustrative rather than limiting. Therefore, this invention is not limited to the examples described in the specific embodiments. Any other embodiments derived by those skilled in the art based on the technical solutions of this invention, without departing from the spirit and scope of this invention, whether modifications or substitutions, are also within the protection scope of this invention.

Claims

1. A method for constructing a vehicle body distortion model, characterized in that: Includes the following steps: The similarity factor of each design variable in the equivalent vehicle body is obtained based on the similarity principle; Based on the principle of stiffness equivalence, an equivalent full-size train body model was established, which is equivalent to the full-size prototype train body. Based on the similarity factor of the design variables and the required thickness or preset thickness distortion coefficient, a vehicle body distortion model is constructed on the basis of the full-size vehicle body equivalent model. Specifically, for design variables other than vehicle body thickness on the vehicle body distortion model, the model is scaled based on the corresponding similarity factor on the basis of the full-size vehicle body equivalent model; the vehicle body thickness of the vehicle body distortion model is set according to the preset thickness distortion coefficient or according to the preset thickness value. Obtain a set of thickness distortion coefficients and dynamic response-time distortion relationships corresponding to the prototype train body, and calculate the distortion coefficients corresponding to dynamic response-time on the body distortion model based on the distortion relationships; The dynamic response-time curve of the vehicle body distortion model is corrected based on the distortion coefficient corresponding to the dynamic response-time, and the vehicle body distortion model is constructed. Each type of prototype train body structure corresponds to a set of thickness distortion coefficients and dynamic response-time distortion relationships; the process of constructing the thickness distortion coefficients and dynamic response-time distortion relationships for any type of prototype train body structure is as follows: A: Construct the car body baseline model and the car body distortion model. That is, after obtaining the full-size car body equivalent model corresponding to the full-size prototype train car body, construct a series of car body distortion models and record the thickness distortion coefficient corresponding to each car body distortion model, as well as the car body baseline model for constructing the full-size car body equivalent model. Among them, all design variables except thickness on each vehicle body distortion model and all design variables including thickness on the vehicle body reference model are scaled on the full-size vehicle body equivalent model according to the corresponding similarity factor, and the similarity factor values ​​corresponding to the same type of design variables are the same between different models. B: Perform collision simulations / experiments on each vehicle body distortion model and vehicle body baseline model to obtain the dynamic response-time curves for each model. C: Compare the dynamic response-time curve of each vehicle body distortion model with the dynamic response-time curve of the vehicle body reference model to obtain a set of dynamic response prediction coefficients and time prediction coefficients corresponding to each vehicle body distortion model; Wherein, the dynamic response prediction coefficient and the time prediction coefficient are the ratio of the dynamic response of a set of reference points on the vehicle body distortion model and the vehicle body reference model on their respective dynamic response-time curves, and the ratio of time; D: Based on several sets of dynamic response prediction coefficients, time prediction coefficients, and thickness distortion coefficients corresponding to the series of vehicle body distortion models, a relationship between the thickness distortion coefficient and the dynamic response prediction coefficient and the time prediction coefficient is fitted. The relationship represents the distortion relationship between the thickness distortion coefficient and the dynamic response-time.

2. The method for constructing a vehicle body distortion model according to claim 1, characterized in that: The relationship between the thickness distortion coefficient and the dynamic response and time is expressed as follows: ； In the formula, Represents the prediction coefficients of the dynamic response of type j. Indicates the time prediction coefficient. Indicates the thickness distortion coefficient. A set of coefficients representing the relationship between the dynamic response prediction coefficient and the thickness distortion coefficient. A set of coefficients representing the relationship between the time prediction coefficient and the thickness distortion coefficient.

3. The method for constructing a vehicle body distortion model according to claim 1, characterized in that: The types of dynamic responses include: displacement, acceleration, and velocity.

4. The method for constructing a vehicle body distortion model according to claim 1, characterized in that: The distortion coefficient corresponding to the dynamic response-time includes the dynamic response prediction coefficient and the time prediction coefficient; The relationship between the thickness distortion coefficient and the distortion of the dynamic response-time is the relationship between the thickness distortion coefficient and the dynamic response prediction coefficient and the time prediction coefficient. The dynamic response-time curve of the vehicle body distortion model, which is corrected based on the distortion coefficient corresponding to the dynamic response-time, includes at least the following: The corrected dynamic response on the dynamic response-time curve is calculated using the following formula: ,in, The corrected dynamic response, The dynamic response of the vehicle body distortion model. This represents the prediction coefficient for the corresponding type j dynamic response.

5. The method for constructing a vehicle body distortion model according to claim 1, characterized in that: The similarity factors for each design variable are as follows: 、 、 、 、 、 、 、 ； In the formula, For size similarity factor, , , , , , , , These are the length similarity factor, force similarity factor, time similarity factor, velocity similarity factor, acceleration similarity factor, mass similarity factor, stiffness similarity factor, and energy similarity factor, respectively.

6. A method for constructing a train model, characterized in that: include: The full-size prototype train was structurally disassembled into the car body and energy absorption device. The vehicle body distortion model in the train model is constructed according to the vehicle body distortion model construction method according to any one of claims 1-5; The energy absorption device in the train model is constructed based on the similarity factor and energy absorption characteristic curve.

7. A train model based on the vehicle body distortion model construction method according to any one of claims 1-5, characterized in that: Including the lead car and the middle car; The lead vehicle includes a lead vehicle body and a lead vehicle energy absorption device; the intermediate vehicle includes an intermediate vehicle body and an intermediate vehicle energy absorption device; the lead vehicle body and the intermediate vehicle body are both constructed with a vehicle body distortion model according to the vehicle body distortion model construction method.

8. A system based on the vehicle body distortion model construction method according to any one of claims 1-5, characterized in that: include: The similarity factor acquisition module is used to obtain the similarity factors of each design variable in the vehicle body equivalent based on the similarity principle; The full-size car body equivalent model construction module is used to establish a full-size car body equivalent model that is equivalent to the full-size prototype train car body based on the stiffness equivalence principle; The vehicle body distortion model construction module is used to construct a vehicle body distortion model based on the similarity factor of the design variables and the required thickness or preset thickness distortion coefficient, on the basis of the full-size vehicle body equivalent model. Specifically, for design variables other than vehicle body thickness on the vehicle body distortion model, the model is scaled based on the corresponding similarity factor on the basis of the full-size vehicle body equivalent model; the vehicle body thickness of the vehicle body distortion model is set according to the preset thickness distortion coefficient or according to the preset thickness value. The calculation module is used to obtain a set of thickness distortion coefficients and dynamic response-time distortion relationships corresponding to the prototype train body, and calculate the distortion coefficients corresponding to the dynamic response-time on the body distortion model based on the distortion relationships. The correction module is used to correct the dynamic response-time curve of the vehicle body distortion model based on the distortion coefficient corresponding to the dynamic response-time, thereby completing the construction of the vehicle body distortion model.

9. A system based on the train model construction method of claim 6, characterized in that: include: The decomposition module is used to structurally decompose the full-size prototype train into the car body and energy absorption device. The vehicle body distortion model construction module is used to construct the vehicle body distortion model in the train model; The energy absorption device construction module is used to construct energy absorption devices in train models based on similarity factors and energy absorption characteristic curves. The vehicle body distortion model construction module includes: The similarity factor acquisition module is used to obtain the similarity factors of each design variable in the vehicle body equivalent based on the similarity principle; The full-size car body equivalent model construction module is used to establish a full-size car body equivalent model that is equivalent to the full-size prototype train car body based on the stiffness equivalence principle; The vehicle body distortion model construction module is used to construct a vehicle body distortion model based on the similarity factor of the design variables and the required thickness or preset thickness distortion coefficient, on the basis of the full-size vehicle body equivalent model. Specifically, for design variables other than vehicle body thickness on the vehicle body distortion model, the model is scaled based on the corresponding similarity factor on the basis of the full-size vehicle body equivalent model; the vehicle body thickness of the vehicle body distortion model is set according to the preset thickness distortion coefficient or according to the preset thickness value. The calculation module is used to obtain a set of thickness distortion coefficients and dynamic response-time distortion relationships corresponding to the prototype train body, and calculate the distortion coefficients corresponding to the dynamic response-time on the body distortion model based on the distortion relationships. The correction module is used to correct the dynamic response-time curve of the vehicle body distortion model based on the distortion coefficient corresponding to the dynamic response-time, thereby completing the construction of the vehicle body distortion model.

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