Method for constructing multi-passenger coupled collision damage model of subway train

Abstract

The invention relates to a subway train multi-passenger coupled collision damage model construction method, and belongs to the field of subway collision damage model construction. According to the method, aiming at the characteristics of more passengers, random distribution, complex environment and the like in the subway train, the spatial partition modeling method suitable for researching the multi-passenger coupling damage of the subway train is provided in combination with the characteristics of subway train compartment interior distribution and passenger distribution; based on the method, damage characteristics and risk rules of passengers in the subway train under different passenger densities and different spaces are mainly explored, and finally, safety protection of collision of multiple passengers in the subway train is achieved by adjusting the layout of compartment interiors. According to the method, the passenger distribution characteristics of the subway train and the damage rule of compartment interior trim arrangement to different types of passengers can be explored, and a research basis is provided for reducing the passenger damage risk in the subway train.

Description

Technical Field

[0001] The present invention belongs to the field of subway collision damage model construction, and in particular relates to a method for constructing a subway train multi-passenger coupled collision damage model. Background Art

[0002] Urban rail transit, with its large capacity, high efficiency, low energy consumption, and convenient access, has become a crucial means of alleviating urban traffic congestion, achieving urban spatial restructuring, and promoting balanced urban development. According to internationally accepted statistical standards, urban rail transit is categorized into three main types: subways, light rail, and trams. Global urban rail transit operational statistics show that by the end of 2023, 563 cities in 79 countries and regions had operational urban rail transit systems, with subways, light rail, and trams accounting for 50.07%, 10.69%, and 39.24%, respectively. In cities, subways have become a primary means of transportation to alleviate traffic congestion and a crucial mode of transportation for urban residents.

[0003] Rail transit is considered the safest mode of land transportation, and its safety is constantly improving. With the development of onboard intelligence, train reliability and active collision avoidance have significantly improved. However, rail transportation is a complex and extensive system, and actual operations are subject to the influence of human factors, environmental factors, and system-specific factors, making rail vehicle collisions difficult to avoid. Due to the high passenger volume during subway operations, a train collision can result in multiple casualties. Therefore, research on the collision injury risks and protective measures associated with the coupled interactions between passengers in subway trains is crucial.

[0004] From the perspective of collision injury risk, subway train passengers exhibit the following characteristics compared to cars, also used for land transportation. First, subway train passengers are numerous and randomly distributed. The number of passengers on subway trains fluctuates in real time due to varying travel times and locations. For example, passenger flow on subway trains increases significantly during peak hours in the morning and evening, and stations near the city center typically have higher passenger flow than those in the city's periphery. These temporal and spatial variations contribute to the randomness of the number of passengers on a train. Second, the state of passengers and their surroundings on subway trains are diverse. In addition to seats, subway trains also feature interior features such as handrails to provide grip for standing passengers. Due to the varying interior layouts and styles, passenger postures vary, and the choice of seating, gripping, or standing positions also creates a diverse environment for passengers. Third, subway train passengers lack restraint systems. While in the automotive industry, seatbelts, airbags, seats and headrests, and steering mechanisms are typically used to mitigate injury risk, subway train passengers rely primarily on seats, handrails, and side panels. Because subway trains need to accommodate a large passenger flow, the space inside the car is relatively spacious, and passengers have more room to move in the event of a secondary collision.

[0005] There are generally two reasons why passengers are injured in train collisions: the first is because the integrity of the train body structure is destroyed, resulting in the loss of passenger survival space, passengers being squeezed, or passengers being stabbed by foreign objects or thrown out of the car; the second is the damage caused by secondary collisions between passengers and internal facilities in the car. When there is no obvious deformation of the vehicle, the secondary collision between passengers and the body or interior is the main cause of passenger injury. Therefore, to reduce the risk of injury to passengers in subway trains, the vehicle must first have a certain degree of crashworthiness and provide a reasonable deceleration. The current standard EN15227 provides a relatively detailed description of the requirements for vehicle crashworthiness and post-collision structural integrity, and stipulates the survival space for passengers and drivers after a collision. Domestic and foreign researchers have also conducted collision impact tests, numerical simulation studies, and parameter optimization designs on the overall vehicle structure, vehicle front-end structure, and crashworthiness components in response to vehicle crashworthiness issues. At the same time, based on the characteristics of passengers in subway trains, it is very important to carry out research on reducing the distance passengers move in the car when a collision occurs, reducing the relative speed between passengers and the car or interior, optimizing the car space and interior layout, and reasonably setting the contact stiffness between passengers and the car, so as to reduce the injury risk of passengers in subway trains.

[0006] Researchers both domestically and internationally have conducted relatively extensive research on secondary impacts involving rail vehicle occupants, focusing primarily on the dynamic response of individual occupants within the carriage and the surrounding environment. Compared to other rail vehicles, subway train occupants are characterized by a large number of passengers, a complex environment, and the absence of restraint systems. While studies on seated subway train occupants have focused on the coupling between multiple occupants, research on standing subway train occupants has primarily focused on the dynamic response of individual occupants within the carriage. Summary of the Invention

[0007] The purpose of the present invention is to focus on the interaction between passengers in subway cars, explore the characteristics of passenger distribution in subway trains and the damage patterns of different types of passengers caused by the interior layout of the car, and provide a research basis for reducing the risk of passenger injury in subway trains. Therefore, a method for constructing a collision damage model of multiple passengers coupled in subway trains is provided. This method targets the characteristics of a large number of passengers, random distribution, and a complex environment in subway trains, and combines the characteristics of the interior distribution and passenger distribution of subway train cars to propose a spatial partitioning modeling method suitable for studying the damage of multiple passengers coupled in subway trains. Based on this method, the damage characteristics and risk patterns of passengers in subway trains under different population densities and different spaces are explored in detail. Finally, safety protection against collisions of multiple passengers in subway trains is achieved by adjusting the interior layout of the car.

[0008] To achieve the above-mentioned purpose, the technical solution of the present invention is: a method for constructing a subway train multi-passenger coupled collision damage model, comprising:

[0009] Based on the seating and standing areas of subway train cars and the spatial distribution and occupant distribution characteristics of subway train cars, the subway train car space is divided into six characteristic areas: seats, end door areas at the ends of the car, middle door areas in the middle of the car, door area-end wall area, end wall area-door area, and seating area in the middle of the car.

[0010] For the six characteristic areas identified, simulations were performed on seated occupant injuries under different numbers of people and different position distributions. The distribution characteristics were then correlated with the occupant injury risk, resulting in a distribution pattern with a lower occupant injury risk, which served as a reference for passenger seat position selection. The number of people in each standing characteristic area was represented by the vehicle's standing seat density. Randomly selected distribution conditions were used to evaluate the relationship between the vehicle's standing seat density and occupant injury risk, identifying dangerous locations under different vehicle standing seat densities.

[0011] Based on the occupant injury risk caused by a collision between subway train cars, an improvement method for the car interior layout based on the multi-occupant coupled collision injury risk is proposed.

[0012] Furthermore, for the six divided characteristic areas, the multi-rigid body-finite element coupling method is selected to establish the car body-multi-occupant coupling model of each characteristic area after partitioning, and the dummy model used for occupant injury research in each characteristic area is selected and the parameters are determined.

[0013] Furthermore, the multi-rigid body-finite element coupling method is selected to establish the car body-multi-occupant coupling model of each characteristic area after partitioning. That is, based on the multi-rigid body simulation software MADYMO and the finite element calculation software LS-DYNA, a coupling model of multi-rigid body dummy-finite element car body environment is constructed.

[0014] Furthermore, the sitting dummy model adopts the ES-2 ellipsoid model in MADYMO, and the standing dummy model adopts the ellipsoid pedestrian model of the standing human body model in MADYMO.

[0015] Furthermore, a seated occupant coupling model is established to numerically simulate occupant injuries under different distribution states. Using damage evaluation indicators and damage risk descriptions, the seated occupant distribution characteristics are correlated with seated occupant injuries, and the injury patterns of multi-seating occupants on longitudinal seats are obtained.

[0016] Furthermore, the calculation formula for the comprehensive injury evaluation index of seated occupants is as follows:

[0017]

[0018] Among them, HIC is the head injury index, RDC is the chest injury index, APF is the abdomen injury index, and PSPF is the pelvic injury index;

[0019] Based on the head injury index, chest injury index, abdomen injury index, and pelvic injury index, the head injury curve, chest injury curve, abdomen injury curve, and pelvic injury curve are calculated. Specifically,

[0020] Head injury risk curve using acceleration-based HIC 36 The value is calculated as follows:

[0021]

[0022] Where Φ is the probability curve of injury, μ is the mean of the curve, and σ is the standard deviation of the curve. For AIS2+, μ = 6.96352, σ = 0.84664; for AIS 3+, μ = 7.45231, σ = 0.73998; for AIS 4+, μ = 7.65605, σ = 0.60580. AIS is the Abbreviated Injury Scale, which stratifies and classifies the severity of injuries to all areas of the body by grade numbers, where grade 0 indicates no injury, grade 1 indicates minor injury, and so on, up to grade 6, which is the most severe injury.

[0023] The chest injury curve uses the maximum value of rib compression, and the injury curve formula is as follows:

[0024]

[0025] The chest damage curve can also be calculated using the chest viscosity index, as follows:

[0026]

[0027] The abdominal-related risk curve uses the abdominal peak force APF, which is calculated as follows:

[0028]

[0029] The pelvic risk curve uses the pubic symphysis peak force (PSPF) with the following formula:

[0030]

[0031] Furthermore, considering the influence range on both sides of the characteristic area, damage evaluation indicators are selected to evaluate the injury degree of the occupants, and the injury patterns of standing occupants in the middle area of the subway car under different standing seat densities are obtained. The middle area of the subway car includes the middle door area and the seat area in the middle of the car.

[0032] Furthermore, the calculation formula for the comprehensive injury evaluation index of standing occupants is as follows:

[0033]

[0034] Among them, HIC 36 is the head injury index, C 3ms is the chest injury index, FF left , FF right are the left and right leg injury indicators, respectively;

[0035] Based on the head injury index, chest injury index, left and right leg injury index, the head injury curve, chest injury curve, thigh and calf injury curve are calculated. Specifically,

[0036] Head injury risk curve using acceleration-based HIC 36 The value is calculated as follows:

[0037]

[0038] Where Φ is the probability curve of injury, μ is the mean of the curve, and σ is the standard deviation of the curve. For AIS2+, μ = 6.96352, σ = 0.84664; for AIS 3+, μ = 7.45231, σ = 0.73998; for AIS 4+, μ = 7.65605, σ = 0.60580. AIS is the Abbreviated Injury Scale, which stratifies and classifies the severity of injuries to all areas of the body by grade numbers, where grade 0 indicates no injury, grade 1 indicates minor injury, and so on, up to grade 6, which is the most severe injury.

[0039] The chest injury curve uses the chest 3ms synthetic acceleration C 3ms The damage curve formula is as follows:

[0040]

[0041]

[0042] The thigh injury curve is calculated as follows:

[0043]

[0044] Among them, FF refers to the femoral strength;

[0045] The calf injury curve has the following formula:

[0046]

[0047] Among them, a tibia is the peak acceleration of the calf.

[0048] Furthermore, the correlation between the occupant injury pattern in each characteristic area and the standing seat density of the entire vehicle and the source of the dangerous position were analyzed to obtain the injury pattern of standing occupants in the end areas of the subway car under different standing seat densities. The end areas of the subway car include the end door area, the door area-end wall area, and the end wall area-door area located at the end of the car.

[0049] Furthermore, based on the risk of multi-occupant coupled collision damage, a method for improving the interior layout of the vehicle cabin is developed. The idea of forming partitions in the interior and guiding occupants to lower-risk positions is used to improve the interior layout of the vehicle cabin, so as to effectively reduce the risk of collision damage under multi-occupant coupling.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] (1) A modeling method suitable for the study of coupling damage of multiple passengers in subway trains was proposed. According to the space and interior distribution of subway train cars and the preferences and distribution characteristics of passengers, the cars were divided into six characteristic areas: seats, end door areas, middle door areas, door areas-end wall areas, end wall areas-door areas, and seats. In response to the numerical calculation requirements of multiple passengers in subway trains, the finite element-multi-rigid body coupling calculation method was selected to carry out the research. Based on the verified and optimized multi-rigid body dummy model and the car finite element model, the coupling calculation models of the six characteristic areas after partitioning were established respectively, and the effectiveness of the coupling model parameter settings was verified through a sled test based on passengers sitting in the forward position of the subway train.

[0052] (2) The damage mechanism of multiple occupants coupled with different numbers of people in each characteristic area was explored. By carrying out simulation calculations on seated occupant injuries with different numbers of people and different position distributions, the distribution characteristics were correlated with the occupant injury risk, and a distribution method with a lower occupant injury risk was obtained, providing a reference for passengers to choose seat positions. The number of people in each standing characteristic area was represented by the standing seat density of the entire vehicle. The relationship between the standing seat density of the entire vehicle and the occupant injury risk was evaluated through randomly selected distribution conditions, and dangerous positions under different standing seat densities of the entire vehicle were identified.

[0053] (3) A method for improving the interior layout of the vehicle cabin based on the risk of multi-occupant coupling collision damage is proposed. The interior layout is improved by using the idea of forming partitions and guiding occupants to lower-risk positions. The improved scheme can effectively reduce the risk of collision damage under multi-occupant coupling. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 Schematic diagram of the overall structure of the method of the present invention.

[0055] Figure 2 The distribution of compartment space areas.

[0056] Figure 3This is an illustration of the passenger distribution area in the carriage.

[0057] Figure 4 The partitions of the subway car.

[0058] Figure 5 It is a multi-passenger-carriage coupling model.

[0059] Figure 6 The injury risk of each dummy when two dummies are randomly distributed.

[0060] Figure 7 Distribution patterns with lower injury risk for different numbers of people.

[0061] Figure 8 Description of the working conditions for studying the impact of the number of people in the front and rear.

[0062] Figure 9 Occupant distribution diagram when the standing seat density of the whole vehicle is 6 people / m2.

[0063] Figure 10 Comparison of the number of people with uniform and non-uniform distribution in each region.

[0064] Figure 11 The impact of seated occupants on the injury risk of standing occupants in the seating area.

[0065] Figure 12 Distribution diagram of occupant overall injury risk under different overall standing seat densities in the door area.

[0066] Figure 13 Distribution diagram of occupant overall injury risk in the end wall area and seating area at different overall standing seat densities.

[0067] Figure 14 Risk of occupant injury at various positions in the end door area.

[0068] Figure 15 Risk of occupant injury at various positions in the center door area.

[0069] Figure 16 The risk of occupant injury at various positions in the door area and the end wall area.

[0070] Figure 17 Occupant injury risk at various positions in the door area, from the end wall area to the door area.

[0071] Figure 18 The risk of occupant injury at various positions in the door area, end wall area and middle end wall area.

[0072] Figure 19 Occupant injury risks at various locations in the end wall area, including the end wall area and the door area.

[0073] Figure 20 Risk of injury to occupants in various seating areas.

[0074] Figure 21 Interior layout adjustment plan.

[0075] Figure 22 Interior layout adjustment plan. DETAILED DESCRIPTION

[0076] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0077] The present invention provides a method for constructing a subway train multi-passenger coupled collision damage model, comprising:

[0078] Based on the seating and standing areas of subway train cars and the spatial distribution and occupant distribution characteristics of subway train cars, the subway train car space is divided into six characteristic areas: seats, end door areas at the ends of the car, middle door areas in the middle of the car, door area-end wall area, end wall area-door area, and seating area in the middle of the car.

[0079] For the six characteristic areas identified, simulations were performed on seated occupant injuries under different numbers of people and different position distributions. The distribution characteristics were then correlated with the occupant injury risk, resulting in a distribution pattern with a lower occupant injury risk, which served as a reference for passenger seat position selection. The number of people in each standing characteristic area was represented by the vehicle's standing seat density. Randomly selected distribution conditions were used to evaluate the relationship between the vehicle's standing seat density and occupant injury risk, identifying dangerous locations under different vehicle standing seat densities.

[0080] Based on the occupant injury risk caused by a collision between subway train cars, an improvement method for the car interior layout based on the multi-occupant coupled collision injury risk is proposed.

[0081] The following is a specific implementation process of the present invention.

[0082] like Figure 1 As shown, the present invention provides a method for constructing a collision damage model of multiple passengers in a subway train, which specifically includes the following contents:

[0083] S1. Method for establishing a multi-occupant zoning model for subway trains. To address the large space and high passenger density of subway cars, the car space was rationally partitioned based on the characteristics of the car interior and the distribution of passengers. To ensure the accuracy of the results and improve research efficiency, a multi-rigid-body-finite element coupling method was used to establish a car-multi-occupant coupled model for each characteristic area after partitioning. Dummies were selected and parameters were determined for occupant injury studies in each characteristic area. The accuracy of the parameter settings for the established zoning was verified based on subway passengers sitting in a forward-facing position.

[0084] S2. Injury patterns of occupants in multiple seating positions on longitudinal seats. To investigate the injury patterns of occupants in longitudinal seats under random number and position conditions, numerical simulations of occupant injuries under different distribution conditions were conducted based on the established seat-occupant coupling model. Using appropriate damage assessment indicators and damage risk descriptions, the correlation between distribution characteristics and seat-occupant injuries was explored.

[0085] S3. Study on the injury mechanism of standing passengers in the middle area of subway cars. To explore the injury patterns of standing passengers in the continuous area in the middle of the car, we first considered the impact range on both sides of the characteristic area, selected appropriate damage evaluation indicators to assess the injury degree of passengers, and conducted research on the injury mechanism of passengers in each area under different standing seat densities.

[0086] S4. Study the injury mechanism of standing passengers in the end areas of subway cars. Conduct research on the injury patterns of standing passengers in the end areas of subway cars, analyze the correlation between the injury patterns of passengers in each characteristic area and the standing seat density of the entire car, and the sources of dangerous locations, to provide a research basis for proposing interior layout adjustment plans.

[0087] S5. Improvement Methods for Carriage Interior Layout Based on Occupant Injury Risk. Based on an analysis of the characteristics and patterns of occupant injuries in various areas, further explore the impact of carriage interior layout on occupant injuries and select appropriate interior layout solutions to reduce the injury risk of multiple passenger collisions on subway trains.

[0088] 1. Method for establishing a partition model for multiple passengers in a subway car

[0089] Subway train cars have a large and random number of passengers, and the interactions between them are complex. Although the interior facilities divide the car space into large sections, interactions between passengers still exist, and the interior environment faced by passengers in each section is also different. Finding effective methods to conduct damage analysis for multiple passengers in subway trains is extremely important. Simultaneously studying the injuries of all passengers in an entire car would require a huge amount of computation, which would affect research efficiency.

[0090] To effectively address these issues, this section proposes a multi-occupant study method for subway trains. This method partitions the train compartment space based on interior and occupant distribution characteristics, and separately examines the injury characteristics of occupants in each characteristic area. This approach not only investigates the secondary impact characteristics of occupants under different interior environments, but also discretizes the enormous computational complexity. A MADYMO / LS-DYNA coupling method is also introduced to establish a coupled train compartment-multi-occupant model. First, a Type B train compartment is partitioned according to the proposed subway compartment partitioning method. Then, the rationale for selecting this coupled numerical simulation method is explained, and coupled models of the compartment and multiple occupants are established for each partitioned area.

[0091] 1.1 Subway Car Space Partitioning Method

[0092] 1.1.1 Features of subway car interior

[0093] This paper takes the common A and B type cars as examples to analyze the characteristics of the interior space. Combining the actual interior layout of the car, it can be found that regardless of whether it is a type A car or a type B car, the car space provides a seating area and a standing area. The seating area is mostly concentrated between the doors, and the standing area is divided into multiple areas with different boundaries by the seats, doors and other car facilities. According to the surrounding interior characteristics, the standing area is named as the end wall area, door area and seat area. Figure 2 shown.

[0094] 1.1.2 Characteristics of subway passenger distribution

[0095] Passengers have different preferences for location selection under the influence of different travel attributes, car seat density, interior layout, etc. Most studies divide the location selection area into the following categories: Figure 3 As shown, the cabin space can be divided into characteristic areas with the same characteristics according to the passenger's preferences.

[0096] 1.1.3 Subway Car Partitioning Methods

[0097] Combining the distribution characteristics of the interior decoration of the carriage and the distribution characteristics of the passengers in the carriage, the subway carriage can be divided into the following areas, which can be further summarized into six characteristic areas, such as Figure 4 As shown. Subway train cars are provided with seating and standing areas. Because of the obstruction of the seat end structures at both ends of the seats, when all passengers are seated on the seats, the injury patterns of seated passengers can be studied independently from those of standing passengers. The seating area and the middle door area in the middle of the car have adjacent areas on both sides, and the passengers in these areas will have an impact on these areas. The end door areas at the ends of the car, as well as the door area-end wall area and the end wall area-door area composed of the door area and the end area have adjacent areas on only one side, and the passengers in these areas will also have an impact on the passengers in these areas. Subsequently, models will be established for these six characteristic areas and research on the injury patterns of passengers in these areas will be carried out.

[0098] 1.2 Establishment of subway train car-multi-passenger coupling model

[0099] In order to establish the car-multi-occupant coupling model for each characteristic area after the above division, it is necessary to first select a numerical calculation model suitable for the study of multi-occupant damage in subway trains, and then establish the car and occupant models for each area separately.

[0100] 1.2.1 Selection of numerical calculation methods for multi-occupant injury studies

[0101] In the study of multi-occupant injuries on subway trains, the analysis of dummy model results focuses more on the dummy's motion trajectory and overall damage when multiple passengers are present during a collision, with less in-depth research on individual parts of a particular dummy. The multi-rigid-body dummy model can obtain the required results while saving computational time, improving the efficiency of subsequent research on the impact of influencing factors on the patterns of multi-occupant injuries. The interior structures in the partitioned areas are complex and diverse. In addition to spatial dimensions, the interior structure is the primary factor affecting occupant secondary collisions. Therefore, when proposing measures to reduce the risk of injury in multi-occupant collisions, the interior structure cannot be ignored. In order to obtain the deformation of the interior structure during the collision in subsequent research and to quickly modify the spatial dimensions and interior structure, the finite element method is used to discretize the car environment. In summary, combined with the characteristics of multi-occupant injury research on subway trains, this paper will construct a coupled model of multi-rigid-body dummy and finite element car environment based on the multi-rigid-body simulation software MADYMO and the finite element calculation software LS-DYNA.

[0102] 1.2.2 Selection of Subway Train Sitting Dummy Model

[0103] Common seating in subway trains is longitudinally arranged in rows of multiple seats. When a subway train is struck head-on, passengers in these rows collide with the seat interior from the side. Therefore, this study uses a side-facing seated dummy to investigate injury patterns in seated passengers. This study uses the ES-2 dummy model for multi-occupant collision research. MADYMO provides two ES-2 dummies, and this study selected the ES-2 ellipsoid model as the research object.

[0104] 1.2.3 Selection and Parameter Determination of Subway Train Stance Model

[0105] The standing occupant model provided in the MADYMO software is suitable for frontal, lateral, rear, vertical impact, intermediate impact, and more complex scenarios (such as rollover). It is more biologically accurate than dummy models designed for specific loading directions and is more suitable for a wider range of loading conditions than standard impacts. The standing orientation and surrounding environment of standing occupants in subway trains are random, and the impact loads on occupants are uncertain. Therefore, the MADYMO human model was selected to simulate and analyze injury behavior during subway train collisions. MADYMO provides three standing human models: a polyhedral active human model, a polyhedral pedestrian model, and an ellipsoidal pedestrian model. The ellipsoidal model offers advantages such as faster computational speed, greater robustness, and easier scalability to other human sizes, making it more suitable for injury studies involving multiple occupants in subway trains. To illustrate and verify the neck and head characteristics, the neck characteristics of the human model are further explained and verified and optimized with reference to human neck tests.

[0106] 1.2.4 Finite Element Model of Subway Car and Interior

[0107] A finite element model of the carriages and related interior decorations of each characteristic area of a type B subway train after zoning is established. To ensure good riding comfort for passengers, interior decorations are installed in the carriages to provide grip and support for standing passengers. The interior decorations in the carriages mainly include pillars, handles, armrests, and seat baffles.

[0108] 1.2.5 Establishment of a Multi-passenger-Carriage Coupling Model for Subway Trains

[0109] The ES-2 dummy model provided by MADYMO is coupled with the finite element model of the car seat to study the influence of the injury pattern of seated occupants. The contact between the seated occupant and the car seat is realized using CONTACT.MB_FE. The seat finite element model is set as the slave surface, the dummy model is set as the master surface, and the contact friction coefficient between the two is set to 0.3. The contact between the occupants is realized using CONTACT.MB_MB. The friction coefficient between the two is also set to 0.3. The coupled model is as follows Figure 5 As shown in (a).

[0110] The optimized MADYMO standing dummy model was coupled with the vehicle cabin finite element model to conduct subsequent multi-stance occupant injury studies. The distribution and specific posture of the standing occupant within the vehicle cabin were adjusted by varying the joint parameters of the occupant model. Contact between the standing occupant and the interior of the vehicle cabin was established using CONTACT.MB_FE, with a contact friction coefficient of 0.3. The same method was used to establish contact between the standing occupant and the floor, with a friction coefficient of 0.85 between the standing occupant and the floor.

[0111] Passengers who use pillars, handrails, and grab handles to protect themselves during a collision will grab the handrails to protect themselves. According to statistics, the median grip strength of adult males aged 20-80 is 39kg. Therefore, in addition to defining the contact between the occupant and the interior, a failure control must be defined to simulate the contact failure of the hand after the grip strength is exceeded. The contact force between the occupant's hand and the armrest is recorded through "SENSOR.CONTACT". When the contact force exceeds the grip strength setting value, "SWITCH.SENSOR" and "STATE.CONTACT" are used to fail the contact between the hand and the armrest. The coupled standing multi-occupant model is as follows: Figure 5 As shown in (b).

[0112] 2. Injury patterns of occupants in various sitting positions on longitudinal seats

[0113] This section focuses on the injuries to occupants in longitudinal seats in subway trains. First, the random distribution of different numbers of occupants on the seats is analyzed. Then, a multi-occupant coupling model with seat posture is established to study the impact of environmental parameters, seat materials, etc. on the occupant injury risk. Next, the damage mechanism under the random distribution of occupants on the seats is studied, and a clustering method is used to classify the damage characteristics to obtain the injury characteristics of seated occupants under random distribution. Finally, the distribution characteristics that lead to a higher injury risk are studied in combination with the injury characteristics. Under the condition of considering the uncertainty of the collision side, a distribution method with a lower occupant injury risk is obtained.

[0114] 2.1 Distribution of seated occupants under different numbers

[0115] When riding the subway, passengers choose seats based on their preferences. The vertical rows of seats between the doors on a typical subway train are designed to seat six people. Assuming that passengers choose their seats according to the designed seating positions, the distribution of seating positions for different numbers of passengers can be obtained using permutation and combination methods.

[0116] 2.2 Description of injury assessment indicators for seated occupants

[0117] Because the railway industry has not proposed injury indicators and limit values for occupants in side collisions, the injury evaluation indicators for occupants in side collisions are evaluated by referring to the European standard ECE-R95 and the 2015 version of C-NCAP. The damage to the ES-2 dummy is evaluated, and the head HIC value, rib compression RDC, abdominal peak force (APF), and peak force at the pubic symphysis (PSPF) are selected as evaluation indicators.

[0118] In order to evaluate the overall damage of occupants during a collision and the distribution of damage to multiple occupants under various boundary conditions, it is necessary to provide a comprehensive damage evaluation index for the overall damage. According to the WIC determination method, the occupant injury index and weights in side collisions are combined to obtain an overall index suitable for side collisions. The weights are determined by the hierarchical analysis method. The importance of damage to each part is clarified based on accident statistics. The weights of the head, chest, abdomen, and pelvis are 0.18, 0.59, 0.18, and 0.05, respectively. The resulting comprehensive evaluation index expression is:

[0119]

[0120] Among them, HIC is the head injury index, RDC is the chest injury index, APF is the abdomen injury index, and PSPF is the pelvic injury index;

[0121] Based on the head injury index, chest injury index, abdomen injury index, and pelvic injury index, the head injury curve, chest injury curve, abdomen injury curve, and pelvic injury curve are calculated. Specifically,

[0122] Head injury risk curve using acceleration-based HIC 36 The value is calculated as follows:

[0123]

[0124] Where Φ is the probability curve of injury, μ is the mean of the curve, and σ is the standard deviation of the curve. For AIS2+, μ = 6.96352, σ = 0.84664; for AIS 3+, μ = 7.45231, σ = 0.73998; for AIS 4+, μ = 7.65605, σ = 0.60580. AIS is the Abbreviated Injury Scale, which stratifies and classifies the severity of injuries to all areas of the body by grade numbers, where grade 0 indicates no injury, grade 1 indicates minor injury, and so on, up to grade 6, which is the most severe injury.

[0125] The chest injury curve uses the maximum value of rib compression, and the injury curve formula is as follows:

[0126]

[0127] The chest damage curve can also be calculated using the chest viscosity index, as follows:

[0128]

[0129] The abdominal-related risk curve uses the abdominal peak force APF, which is calculated as follows:

[0130]

[0131] The pelvic risk curve uses the pubic symphysis peak force (PSPF) with the following formula:

[0132]

[0133] 2.3 Injury patterns of seated occupants under different occupant distributions

[0134] 2.3.1 Study on the law of single occupant injury due to initial position

[0135] When there is only one occupant in the seat, the occupant's random position determines the distance from the end plate to the occupant. From the perspective of the occupant's dynamic impact response, changes in the dummy's initial position primarily affect the dummy's tilt angle before collision with the baffle, resulting in different injuries to various parts of the body. The injury indicators and comprehensive evaluation index (WIC) for dummies at different positions are shown in Table 1. It can be seen that the occupant in the middle position has a significant risk of head injury and a higher comprehensive injury index.

[0136] Table 1 Injury risk values of various parts of the dummy at different positions

[0137]

[0138] Research shows that the most popular seating positions for passengers in subway trains are Position 1 and Position 6, close to the baffle, chosen by approximately 71% of passengers. From the perspective of collision damage, these two positions are relatively less susceptible to damage. Approximately 24% of passengers choose seats in the middle with relatively ample space. These two positions are more susceptible to damage. Therefore, guiding passengers to sit closer to the side and improving their head impact injuries can effectively reduce the risk of injury.

[0139] 2.3.2 Impact of Multiple Occupant Injuries in Seating Positions with Two or More People

[0140] When multiple dummies are placed on a seat, the dummy closest to the baffle is called Dummy 1, and the other dummies are numbered similarly. When two dummies are placed on a seat, the coupling effect between Dummy 2 and Dummy 1 is analyzed by comparing the injury conditions of a single occupant.

[0141] like Figure 6 As shown in the figure, based on the injury results for the two occupants under random distribution, Dummy 1's head injury risk is related to its own position, while Dummy 2's head injury risk is significantly affected by Dummy 1. The distance between Dummy 2 and Dummy 1 determines the change in Dummy 2's posture, the impact point between Dummy 2 and Dummy 1, and the state of Dummy 1, ultimately determining the injury risk. Under various distribution patterns, Dummy 2 has a lower proportion of significant head injury risks, while Dummy 1 has a higher chest injury risk than Dummy 2. Both Dummy 1 and Dummy 2 have lower pelvic injury risks.

[0142] The presence of multiple occupants in a seat further complicates the impact of these occupants. A random distribution of three occupants can be viewed as adding a random occupant to a random distribution of two occupants. Therefore, by comparing the injuries of the third occupant under these random distributions, we can understand the impact of this additional occupant on the injuries of the original two occupants. Similarly, further analysis can be performed with four, five, or six dummies in the seat.

[0143] 2.3.3 Study on the correlation between distribution characteristics and occupant injuries

[0144] Further investigation into the relationship between distribution characteristics and occupant injuries provides guidance for minimizing occupant injuries. This study used the K-means method to classify 192 groups of occupant injuries. By evaluating the cohesion and separation of the clustering results, it was determined that the classification effect was best when clustered into five clusters. The cluster centers and sample points for each cluster when the number of clusters was five are shown in Table 2. It can be seen that the majority of occupant injuries fall into Cluster 1, accounting for 73.96%. At this cluster, the risk of head injury is relatively low, the risk of chest injury is below 30%, and the WIC value is below 0.4. Although the probability of head injury in Cluster 2 is slightly higher than that in Cluster 1, the overall injury risk is relatively low. Occupants in Cluster 3 have a higher risk of chest injury. Analysis of the corresponding distribution characteristics reveals that this is due to the occupants' tendency to tilt slightly during impact, which increases the risk of chest injury from adjacent occupants on the non-impacting side. Occupants in Cluster 4 have a higher risk of chest injury. These occupants are located in the middle, with the impact side being mostly unoccupied, making their heads more likely to impact first. The head injury of the occupant in cluster 5 mainly comes from the collision between the occupant's head and the head of the occupant on the impact side, which creates the risk of head injury.

[0145] Table 2 Cluster centers and sample points of each group

[0146]

[0147] The results of injury feature clustering show that the injury risk of most seated occupants is relatively low, especially when the number of occupants is 4-6. When there are 1-2 empty spaces from the occupants on the impact side and the fender, there is a greater probability of head injury. When the total empty space from the impact side is 1 and there are adjacent occupants on the non-impact side of the occupant, there is a greater probability of chest injury. Considering the uncertainty of the impact side, a single occupant's choice of a seat close to the fender has a lower injury risk during a collision than a seat in the middle. The injury risk of each occupant is also lower when six occupants are fully seated. The distribution of lower injuries to each occupant under other numbers is as follows: Figure 7 shown.

[0148] 3. Study on the injury mechanism of standing passengers in the middle and end areas of subway cars

[0149] 3.1 Determination of adjacent impact range

[0150] The continuous nature of the train compartment precludes a completely independent study of the stance area. Choosing an appropriate method to decouple the characteristic regions for analysis facilitates a balance between accuracy and computational cost. Therefore, we first conducted a study of the adjacent influence range. Using two occupants as the analysis subjects, we examined the changes in their trajectories and injury risk when different numbers of occupants were placed in front of and behind them. This study helped determine the size of the adjacent influence range for subsequent research.

[0151] Build as Figure 8The five working conditions shown in the figure study the influence of the number of passengers in the front and rear, where L-0 means there are no passengers in the front and rear, L-1 means there is one passenger in the front and rear, and so on. Considering the random distribution of passengers in the car, the two passengers as the research subjects are also selected as follows. Figure 8 The results show that when there are three occupants in the front and rear of the vehicle in the longitudinal direction, the maximum longitudinal displacement of the object begins to converge, and the effect of increasing the number of occupants on the maximum displacement becomes smaller.

[0152] 3.2 Relationship between the density of standing seats and the number of people on subway trains

[0153] Refer to the requirements of the opposite seat density in the standard and choose 1-6 people / m 2 When half of the carriage area is considered, the area of the door area, the seating area, and the end wall area are 2.35m 2 、1.66m 2 and 1.88m 2 , assuming the standing density of the vehicle is 6 people / m 2 When the passengers are evenly distributed in the whole car, the number of people in each area is rounded to 14, 10 and 11 respectively. According to the interior position in the car, the distribution of passengers at this time is roughly as follows Figure 9 When the overall standing density is 1-5 people / m 2 When the position of the occupants in each area changes from Figure 9 The distribution positions shown in the figure are randomly selected. The distribution of standing passengers in the car is uneven. The number of people in each area cannot be obtained by multiplying the standing density of the whole car by the area. The distribution of passengers under different standing density of the whole car is obtained according to the probability of passengers choosing a standing position. Comparison of uniform and non-uniform distribution of passengers under different standing density of the whole car Figure 10 shown.

[0154] 3.3 Description of injury assessment indicators for standing occupants

[0155] Combining the description of standing occupant injuries in automobiles and rail vehicles, it can be found that the injury sites of standing occupants are concentrated in the head, chest and lower limbs. Therefore, this invention uses head, chest and leg injury indicators to describe the occupant injury degree. The head is expressed by the HIC value, and the chest indicator is selected because the occupant's standing direction is random, so the chest 3ms synthetic acceleration C is used. 3ms Evaluation: Leg injuries are evaluated by femoral axial force FF, and calf injuries are evaluated by tibial index TI.

[0156] Similar to the side occupant injury assessment, a comprehensive evaluation index is used to evaluate the overall injury of the occupant during the collision. This index characterizes the occupant's head, chest, and leg injuries through a single parameter. The calculation formula is as follows:

[0157]

[0158] Among them, HIC 36 is the head injury index, C 3ms is the chest injury index, FF left , FF right are the left and right leg injury indicators, respectively;

[0159] Based on the head injury index, chest injury index, left and right leg injury index, the head injury curve, chest injury curve, thigh and calf injury curve are calculated. Specifically,

[0160] Head injury risk curve using acceleration-based HIC 36 The value is calculated as follows:

[0161]

[0162] Where Φ is the probability curve of injury, μ is the mean of the curve, and σ is the standard deviation of the curve. For AIS2+, μ = 6.96352, σ = 0.84664; for AIS 3+, μ = 7.45231, σ = 0.73998; for AIS 4+, μ = 7.65605, σ = 0.60580. AIS is the Abbreviated Injury Scale, which stratifies and classifies the severity of injuries to all areas of the body by grade numbers, where grade 0 indicates no injury, grade 1 indicates minor injury, and so on, up to grade 6, which is the most severe injury.

[0163] The chest injury curve uses the chest 3ms synthetic acceleration C 3ms The damage curve formula is as follows:

[0164]

[0165]

[0166] The thigh injury curve is calculated as follows:

[0167]

[0168] Among them, FF is the thigh bone force;

[0169] The calf injury curve has the following formula:

[0170]

[0171] Among them, a tibia is the peak acceleration of the calf.

[0172] 3.4 Simulation study of collision damage process in each characteristic area

[0173] Random working conditions with different standing density in each characteristic area are selected, among which 1-4 people / m 2 Select three working conditions, 5 people / m 2 Select two working conditions and cover the statistical distribution as much as possible, 2 people / m 2 The crew is distributed at 1 person / m 2 The distribution of occupants in adjacent impact areas is then determined by analogy. A multi-rigid-body-finite element coupling model is established for each characteristic area at different seat densities, and simulations are performed to analyze and determine the damage patterns in each area. This provides a basis for subsequently summarizing the relationship between the damage characteristics of each characteristic area and the seat density of the entire vehicle.

[0174] 3.5 Study on the coupling effect of standing / sitting multi-occupant collision injuries

[0175] 3.5.1 Impact of seated occupants on standing occupants

[0176] There may be a mutual influence between standing occupants in the seating area and seated occupants on the seats on both sides. To determine the relationship between the two and the injury risk pattern of standing occupants in the seating area, simulation calculations and analysis were conducted for two situations with and without seated occupants under different standing seat densities. The injury risks under the two working conditions with and without seated occupants were compared. Figure 11 The results show that the chest injury risk of some occupants changes significantly when a seated occupant is present. This chest injury risk arises from the collision between the occupant's chest and the seated occupant's legs. Seated occupants have a relatively small impact on the head and leg injury risks of all occupants.

[0177] At the same time, the impact of standing occupants in the seating area on the injuries of sitting occupants was observed. The results showed that standing occupants in the seating area had little impact on the overall motion trajectory of sitting occupants.

[0178] 3.6 Relationship between damage characteristics of each characteristic area and vehicle standing density

[0179] 3.6.1 Overall Damage Risk Distribution as a Function of Vehicle Seat Density

[0180] The distribution diagram of head and chest injury risks in the four door areas at different overall standing seat densities is shown in the figure below: Figure 12 Except for door zone 4, the mean head injury risk of occupants in the other three zones shows a trend of first decreasing rapidly and then slowly increasing, while the mean chest injury risk shows a trend of first decreasing rapidly and then remaining basically unchanged. In addition, as the overall standing seat density increases, the distribution trend of injury risk becomes more concentrated.

[0181] The distribution diagram of head and chest injury risks in the end wall area and the seating area at different overall standing seat densities is shown in the figure below: Figure 13 The mean head injury risk in end wall area 1 shows a trend of first decreasing, then slowly increasing, and then decreasing as the overall standing density increases. The head injury risk of occupants in end wall area 2 is 3-4 people / m 2 The reason for this is that the risk of chest injury caused by the occupants falling into the tunnel near the middle is relatively small, 1 person / m 2 The mean risk of head injury is larger when the standing density is high, and it tends to decrease with the increase of the overall standing density.

[0182] 3.6.2 Changes in dangerous locations with standing density

[0183] The damage conditions at different locations in the door area with different characteristics under different overall standing seat densities are as follows: Figures 14 to 17 The injury risk of occupants at various positions in the end wall area is shown as follows: Figure 18 and Figure 19 As shown in the figure, the chest injury risk of passengers in the seating area is not significantly higher. Figure 20 shown.

[0184] Overall, at low density, due to less mutual influence between passengers, passengers directly hitting the interior or floor will lead to a greater risk of injury. At this time, the dangerous position is affected by the environment in which the passengers are located. At high density, there is more mutual influence between passengers, and the risk of injury to most passengers is relatively small. At this time, the dangerous positions are concentrated in special locations in each area.

[0185] 4. Improvement Method of Car Interior Layout Based on Multi-Occupant Injury Risk

[0186] By summarizing the dangerous working conditions with the highest average occupant injury risk in each characteristic area at different standing density in previous studies, two ideas for improving interior layout are obtained. One is to add interior decoration around positions with higher occupant injury risk and use the partitions formed by the interior decoration to reduce occupant injuries. The other is to change the occupant's selection preferences through interior layout, add interior decoration at positions with lower occupant injury risk, and guide occupants to positions with lower injury risk.

[0187] Specific measures such as Figure 21 As shown, new pillars are added at the junction of each area, which increases the gripping position and provides separation for the original handle restraint occupants near the middle of the car; a new horizontal handle is added in the door area, which changes the occupants in this area from an unrestrained state to a handle restraint state, increasing the probability of occupants choosing this position; two pillars are added at equal distances in the middle of the seating area, which increases the gripping position and provides separation, and handrails are added between the seats, which changes the restraint method and provides separation; finally, the structure of the seat end is changed to reduce the risk of injury to some standing and sitting occupants.

[0188] Simulation results show that using tubular-2 seat end structures can effectively reduce injury risk for some occupants. For seated occupants, the newly added armrests between seats effectively reduce injury risk for different occupant loads. For standing occupants, the added armrests and grab handles guide more occupants to the seating area.

[0189] In the adjusted interior layout, based on the number of passengers and the most likely distribution under different standing density conditions, and referring to the dangerous working conditions before the interior layout adjustment, a group of working conditions were randomly selected and compared with the results before the interior layout adjustment. The average WIC of all passengers composed of random working conditions in each characteristic area changes with the standing density as shown below: Figure 22 As shown in the figure, the results show that under low standing density, interior layout adjustment cannot completely eliminate dangerous positions. At this time, the average WIC of random working condition is larger than that of minimum working condition. The standing density is 3-5 people / m 2 When the average value of the random working condition is almost the same as the minimum working condition; the standing density is 6 people / m 2 When the vehicle is adjusted to the lowest possible level, the average WIC value of the randomly selected working condition is smaller than that of the minimum working condition because the injury risk of occupants in dangerous positions in the high standing seat density before the interior adjustment is reduced.

[0190] In summary, rational interior layout adjustments not only reduce the risk of injury for seated passengers in longitudinal seats, but also alter passenger preferences for standing passengers within the train car, adjusting the distribution of passengers within each area. The newly added interior design also effectively separates passengers. Interior layout improvements based on guidance and separation are a feasible approach to reducing the risk of injury for multiple passengers on subway trains.

[0191] The above are preferred embodiments of the present invention. Any changes made according to the technical solution of the present invention, as long as the resulting functions and effects do not exceed the scope of the technical solution of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A method for constructing a collision damage model for multiple passengers in a subway train, characterized in that: include: Based on the seating and standing areas of subway train cars and the spatial distribution and occupant distribution characteristics of subway train cars, the subway train car space is divided into six characteristic areas: seats, end door areas at the ends of the car, middle door areas in the middle of the car, door area-end wall area, end wall area-door area, and seating area in the middle of the car. For the six characteristic areas identified, simulations were performed on seated occupant injuries under different numbers of people and different position distributions. The distribution characteristics were then correlated with the occupant injury risk, resulting in a distribution pattern with a lower occupant injury risk, which served as a reference for passenger seat position selection. The number of people in each standing characteristic area was represented by the vehicle's standing seat density. Randomly selected distribution conditions were used to evaluate the relationship between the vehicle's standing seat density and occupant injury risk, identifying dangerous locations under different vehicle standing seat densities. Based on the occupant injury risk caused by a collision between subway train cars, an improvement method for the car interior layout based on the multi-occupant coupled collision injury risk is proposed.

2. The method for constructing a subway train multi-passenger coupled collision damage model according to claim 1, characterized in that: For the six characteristic areas divided, the multi-rigid body-finite element coupling method is selected to establish the car body-multi-occupant coupling model of each characteristic area after partitioning, and the dummy model used for occupant injury research in each characteristic area is selected and the parameters are determined.

3. The method for constructing a subway train multi-passenger coupled collision damage model according to claim 2, characterized in that: The multi-rigid body-finite element coupling method is selected to establish the car body-multi-occupant coupling model of each characteristic area after partitioning. That is, based on the multi-rigid body simulation software MADYMO and the finite element calculation software LS-DYNA, a coupling model of multi-rigid body dummy-finite element car body environment is constructed.

4. The method for constructing a subway train multi-passenger coupled collision damage model according to claim 3, characterized in that: The sitting dummy model adopts the ES-2 ellipsoid model in MADYMO, and the standing dummy model adopts the ellipsoid pedestrian model of the standing human body model in MADYMO.

5. The method for constructing a subway train multi-passenger coupled collision damage model according to claim 1, characterized in that: A seated occupant coupling model is established to numerically simulate occupant injuries under different distribution states. Using damage evaluation indicators and damage risk descriptions, the seated occupant distribution characteristics are correlated with seated occupant injuries, and the injury patterns of multi-seating occupants on longitudinal seats are obtained.

6. The method for constructing a subway train multi-passenger coupled collision damage model according to claim 5, characterized in that: The calculation formula for the comprehensive injury evaluation index of seated occupants is as follows: Among them, HIC is the head injury index, RDC is the chest injury index, APF is the abdomen injury index, and PSPF is the pelvis injury index; based on the head injury index, chest injury index, abdomen injury index, and pelvis injury index, the head injury curve, chest injury curve, abdomen injury curve, and pelvis injury curve are calculated. Specifically, Head injury risk curve using acceleration-based HIC 36 The value is calculated as follows: Where Φ is the probability curve of injury, μ is the mean of the curve, and σ is the standard deviation of the curve. For AIS2+, μ = 6.96352, σ = 0.84664; for AIS 3+, μ = 7.45231, σ = 0.73998; for AIS 4+, μ = 7.65605, σ = 0.60580. AIS is the Abbreviated Injury Scale, which stratifies and classifies the severity of injuries to all areas of the body by grade numbers, where grade 0 indicates no injury, grade 1 indicates minor injury, and so on, up to grade 6, which is the most severe injury. The chest injury curve uses the maximum value of rib compression, and the injury curve formula is as follows: The chest damage curve can also be calculated using the chest viscosity index, as follows: The abdominal-related risk curve uses the abdominal peak force APF, which is calculated as follows: The pelvic risk curve uses the pubic symphysis peak force (PSPF) with the following formula:

7. The method for constructing a subway train multi-passenger coupled collision damage model according to claim 1, characterized in that: Considering the influence range on both sides of the characteristic area, damage evaluation indicators are selected to evaluate the injury degree of the occupants, and the injury patterns of standing occupants in the middle area of the subway car under different standing seat densities are obtained. The middle area of the subway car includes the middle door area and the seat area in the middle of the car.

8. The method for constructing a subway train multi-passenger coupled collision damage model according to claim 7, characterized in that: The calculation formula for the comprehensive injury evaluation index of standing occupants is as follows: Among them, HIC 36 is the head injury index, C 3ms is the chest injury index, FF left , FF right are the left and right leg injury indicators, respectively; Based on the head injury index, chest injury index, left and right leg injury index, the head injury curve, chest injury curve, thigh and calf injury curve are calculated. Specifically, Head injury risk curve using acceleration-based HIC 36 The value is calculated as follows: Where Φ is the probability curve of injury, μ is the mean of the curve, and σ is the standard deviation of the curve. For AIS2+, μ = 6.96352, σ = 0.84664; for AIS 3+, μ = 7.45231, σ = 0.73998; for AIS 4+, μ = 7.65605, σ = 0.60580. AIS is the Abbreviated Injury Scale, which stratifies and classifies the severity of injuries to all areas of the body by grade numbers, where grade 0 indicates no injury, grade 1 indicates minor injury, and so on, up to grade 6, which is the most severe injury. The chest injury curve uses the chest 3ms synthetic acceleration C 3ms The damage curve formula is as follows: The thigh injury curve is calculated as follows: Among them, FF refers to the femoral strength; The calf injury curve has the following formula: Among them, a tibia is the peak acceleration of the calf.

9. The method for constructing a subway train multi-passenger coupled collision damage model according to claim 1, characterized in that: The correlation between the occupant injury pattern in each characteristic area and the standing seat density of the entire vehicle, as well as the source of dangerous positions, was analyzed to obtain the injury pattern of standing occupants in the end areas of subway cars under different standing seat densities. The end areas of subway cars include the end door area, the door area-end wall area, and the end wall area-door area located at the end of the car.

10. The method for constructing a subway train multi-passenger coupled collision damage model according to claim 1, characterized in that: Based on the risk of multi-occupant coupled collision damage, the vehicle interior layout is improved by using the idea of forming interior partitions and guiding occupants to lower-risk positions, so as to effectively reduce the risk of collision damage under multi-occupant coupling.

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