Analysis and evaluation method of crash response and occupant injury of typical fuselage frame sections of civil aircraft

Abstract

The present invention discloses an analysis and evaluation method for crash response of a typical fuselage frame section of a civil aircraft and injury to occupants, and specifically relates to the field of crashworthiness evaluation of civil aircraft, comprising: step S1, establishing a typical fuselage frame section-seat-occupant crash analysis finite element model of a civil aircraft based on a verified fuselage frame section finite element model and a seat / occupant restraint system finite element model; step S2, performing crash simulation calculation using the above model to obtain finite element simulation results, and comparing and correcting the simulation results with experimental data to obtain a verified fuselage frame section-seat-occupant crash analysis finite element model; step S3, evaluating the crash response of the fuselage frame section and the degree of injury to the occupants under the crash impact using the finite element simulation results obtained with the above model; and step S4, performing crash simulation analysis under various working conditions based on the above model to obtain structural crash response, occupant dynamic response and injury conditions, so as to comprehensively evaluate the occupant injury risk.

Description

Technical Field

[0001] The present invention relates to the technical field of civil aircraft crashworthiness assessment, and more specifically, to a method for analyzing and assessing crash responses of typical fuselage frames of civil aircraft and occupant injuries. Background Art

[0002] Crashworthiness refers to the characteristics of the fuselage structure, seat system, etc. that protect the occupants and prevent them from fatal injuries to the greatest extent possible when a civil aircraft crashes or other accidents occur. It is an important manifestation of the safety of civil aircraft. The study of the crashworthiness of civil aircraft needs to consider not only the anti-crash performance of the civil aircraft fuselage structure, but also the level of crash impact loads on the seats and occupants, so as to evaluate the degree of injury and risk of various parts of the occupants. This is the core issue of the study of the crashworthiness of civil aircraft and the main criterion for evaluating the crashworthiness of civil aircraft. By comprehensively evaluating the crash response of civil aircraft frame sections and the injuries to occupants, we can understand the safety of civil aircraft, use the evaluation results to improve the fuselage configuration and internal facilities such as aviation seats, thereby improving its crashworthiness, which can effectively improve the survivability of occupants in civil aircraft crash accidents.

[0003] The full-scale typical fuselage crash test is the most direct and important means to examine and verify the crashworthiness of civil aircraft structures. However, the test is costly, time-consuming, and difficult to evaluate the structural crashworthiness under various crash environments. Currently, advanced numerical calculation methods have been widely used and are also one of the research hotspots. In the simulation analysis of the crashworthiness of civil aircraft fuselages, in order to simplify the model and improve the calculation efficiency, the occupant dummy and the seat restraint system are usually simulated using concentrated mass. Therefore, in the numerical calculation process, only the crash deformation of the fuselage structure and the acceleration response at the seat rails can be obtained, and the dynamic response and injury of various parts of the occupants during the crash cannot be obtained.

[0004] Under the impact load of an aircraft crash, the biomechanical response of the passengers causes damage to various organs of the human body, which is generally divided into mechanical damage and environmental damage. Among them, mechanical damage is caused by contact and acceleration. The survey shows that civil aircraft crash accidents mainly occur during the take-off and approach phases, of which 65% of the accidents caused contact / non-contact injuries to the head, neck and abdominal cavity of the passengers, 45% of the accidents caused injuries to the passengers' spine, and other major types of injuries included invasive injuries to the passengers' lower limbs and legs. As cabin interior facilities that are in direct contact with the passengers, the aviation seat / passenger restraint system plays a key role in ensuring the safety of the passengers during an aircraft crash.

[0005] Foreign research institutions have conducted a large number of full-scale vertical crash / horizontal impact test studies and simulation analyses on transport aircraft structures, and have accumulated a large amount of test data and simulation experience. At the same time, based on verified numerical analysis models, they have further studied the structural crash response and occupant injury under different crash speeds, crash attitudes, crash environments and different loading conditions to support the crashworthiness design and occupant injury analysis of new aircraft models. Domestic crash test studies on civil aircraft fuselage structures lack systematic and in-depth civil aircraft crash safety and occupant safety analysis. The industry mainly uses test methods to demonstrate airworthiness compliance, which has high verification costs and insufficient design methods. There is a large gap with Europe and the United States in simulation analysis and verification, and there are few crash tests and simulation analyses of fuselage frames containing real aviation seats and occupant dummies. Therefore, it is urgent to develop an analysis and evaluation method for crash response and occupant injury of civil aircraft frames. Summary of the invention

[0006] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides an analysis and evaluation method for the crash response of civil aircraft frame sections and occupant injuries. The civil aircraft fuselage frame sections, aviation seats and occupants are taken as research objects, and a finite element model of occupant-seat-fuselage section crash analysis is established based on the test results. The occupant response and injury under different crash conditions are evaluated to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a method for analyzing and evaluating a typical fuselage frame section crash response and occupant injury of a civil aircraft, comprising establishing a typical fuselage frame section-seat-occupant crash analysis finite element model for a civil aircraft, verifying the typical fuselage frame section-seat-occupant crash analysis finite element model, performing a fuselage frame section-seat-occupant crash response and occupant injury analysis under a typical crash condition, and performing an analysis and evaluation of a civil aircraft frame section crash response and occupant injury under a variety of crash conditions, wherein the specific steps are as follows:

[0008] Step S1, establishing a typical fuselage frame section-seat-occupant crash analysis finite element model for civil aircraft: respectively establishing a verified fuselage frame section structure finite element model and a seat / occupant restraint system finite element model, combining the fuselage frame section structure finite element model and the seat / occupant restraint system finite element model to establish a typical fuselage frame section-seat-occupant crash analysis finite element model for civil aircraft;

[0009] Step S2, verifying a typical fuselage frame section-seat-passenger crash analysis finite element model for civil aircraft: first, using the above model calculation to solve the simulation result of the fuselage frame section-seat-passenger crash analysis finite element model, and comparing it with the crash response of the fuselage structure, the dynamic response of the seat, the dynamic response of the passenger dummy and other data obtained from the crash test, to determine the correlation between the simulation result of the finite element model and the test result. When the correlation is poor, the material constitutive structure and failure criterion are corrected to improve the finite element model and thus improve the simulation accuracy, and finally obtain a verified fuselage frame section-seat-passenger crash analysis finite element model;

[0010] Step S3, performing a crash response and occupant injury analysis of a fuselage frame section, seat, and occupant under a typical crash condition: performing a crash simulation under a typical condition based on a verified finite element model for a crash analysis of a fuselage frame section, seat, and occupant, analyzing the crash response of a civil aircraft fuselage frame section and the degree of occupant injury, and evaluating the occupant's head and neck injuries, occupant's lumbar spine injuries, and occupant's femur injuries according to an occupant injury assessment criterion, respectively, to assess the comprehensive occupant injury;

[0011] Step S4, analyzing and evaluating the crash response of typical fuselage frames of civil aircraft and occupant injuries under different crash conditions: based on the verified fuselage frame-seat-occupant crash analysis finite element model, considering different crash conditions and different cargo loading conditions, etc., crash simulations are performed under various crash conditions, and the crash response degree of the fuselage section and the injury degree of the occupants under the crash impact are analyzed and evaluated. According to the injury assessment criteria, the injury assessment of the occupant's head, neck, lumbar spine, femur, etc. is performed respectively.

[0012] In a preferred embodiment, the fuselage frame-seat-occupant crash analysis finite element model mainly includes three parts: a verified fuselage frame model, a verified seat restraint system model, and a calibrated occupant dummy model. The seat restraint system model includes an aviation seat model and a restraint system model.

[0013] In a preferred embodiment, the fuselage frame section model is mainly established using SECTION_SHELL shell elements and the Belytschko-Tsay algorithm; the fuselage material adopts an accurate material constitutive and failure model, and the fasteners adopt solid elements of 8 hexahedral clusters.

[0014] In a preferred embodiment, the aviation seat model is a typical three-seat passenger seat on an airliner, wherein the components on the main force transmission path of the front and rear legs and support plates of the seat, the back cushion and the seat cushion assembly are modeled using SECTION_SOLID solid elements, and the thin-walled structures of the seat tubes, backrests and seat basins are simulated using SECTION_SHELL shell elements, wherein the main load-bearing structural parts of the seat are three strain-rate insensitive aluminum alloy materials, using an elastoplastic material card with model number MAT 024-PIECEWISE LINEARPLASTICITY, and the seat cushion is composed of two parts, polyurethane and polyethylene, using a low-density foam material card with model number MAT057-LOW DENSITYFOAM.

[0015] In a preferred embodiment, the restraint system model is a two-point seat belt and its anchor point. The seat belt adopts a mixed modeling method of one-dimensional SECTION SEATBELT seat belt unit and two-dimensional SECTION SHELL shell unit, and is connected using CNRB. The seat belt material is nylon. The 1D unit in the finite element model uses the MATB01-SEATBELT seat belt material card to simulate the fixation of the seat belt and the anchor point, and the 2D unit uses the MAT 034-FABRIC fabric material card to simulate the interaction between the seat belt and the occupant dummy.

[0016] In a preferred embodiment, the passenger dummy model is a fine simulation dummy of a Hybrid III 50th percentile male. Various sensors installed in the dummy can output compression loads of the femur, tibia and lumbar spine, and acceleration data of the head, and has good bionics.

[0017] In a preferred embodiment, the fuselage frame-seat-occupant crash analysis finite element model sets the contact definition between the components, mainly including: the contact between the fuselage frame and the rigid impact plane, the self-contact of the fuselage frame, the contact between the seat system and the dummy, the contact between the restraint system and the dummy, and the contact between other components inside the seat system.

[0018]

[0019]

[0020] In a preferred embodiment, the fuselage frame-seat-occupant crash analysis finite element model performs crash simulation analysis, compares the deformation mode of the fuselage structure, the movement posture of the occupant dummy, and the load borne by the head and lumbar spine of the occupant dummy to modify the model, and performs crash simulation under different crash postures, different crash speeds, different crash environments, different cargo loadings and other working conditions to achieve a comprehensive analysis and evaluation of the fuselage structure crash response and occupant injuries.

[0021] In a preferred embodiment, the comprehensive injury assessment method is as follows: the occupant injury risk quantitative assessment index includes:

[0022] Lumbar compression load of occupant: FL≤6,672N;

[0023] Compression load of left and right femur of occupant: FF≤10,008N;

[0024] Occupant head injury criterion: HIC≤1,000;

[0025] Occupant neck injury criterion: Nij≤1;

[0026] In addition, the present invention makes a comprehensive assessment of the occupant injury risk with reference to the concept of the comprehensive crashworthiness assessment index (ICI), and the assessment formula is:

[0027]

[0028] Among them, if the seat is always connected to the seat rail, Attach=1, otherwise Attach=0; if the seat deformation does not affect the emergency evacuation of the occupant, Seat=1, otherwise Seat=0; if the seat belt remains restrained at the pelvis of the occupant, Restraint=1, otherwise Restraint=0.

[0029] Technical effects and advantages of the present invention:

[0030] 1. This method is used to analyze and evaluate the crash response of civil aircraft frame sections and occupant injuries. A finite element model for crash dynamics analysis of a typical civil aircraft fuselage section with real seats and occupant dummies is established. The validity of the finite element model is verified based on test data to ensure the credibility of the finite element analysis method.

[0031] 2. This analysis and evaluation method for civil aircraft frame section crash response and occupant injury studies different crash conditions, further reveals the influence law and mechanism of fuselage section structure crash on occupant safety, and provides support for the structural crashworthiness analysis of China's civil aircraft and the airworthiness certification of occupant protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure flow of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Example

[0035] The present invention provides a method for analyzing and evaluating the crash response of a typical fuselage frame section of a civil aircraft and the injuries to the occupants. Figure 1 , including establishing a typical fuselage frame section-seat-occupant crash analysis finite element model for civil aircraft, verifying a typical fuselage frame section-seat-occupant crash analysis finite element model, typical fuselage frame section-seat-occupant crash response and occupant injury analysis, analysis and evaluation of civil aircraft frame section crash response and occupant injury under various working conditions, wherein the occupant injury evaluation includes a comprehensive injury evaluation method, and the specific steps are as follows:

[0036] Step S1, establishing a typical fuselage frame section-seat-occupant crash analysis finite element model for civil aircraft: respectively establishing a verified fuselage frame section structure finite element model and a seat / occupant restraint system finite element model, combining the fuselage frame section structure finite element model and the seat / occupant restraint system finite element model to establish a typical fuselage frame section-seat-occupant crash analysis finite element model for civil aircraft;

[0037] Step S2, verifying a typical fuselage frame section-seat-passenger crash analysis finite element model for civil aircraft: first, using the above model calculation to solve the simulation result of the fuselage frame section-seat-passenger crash analysis finite element model, and comparing it with the crash response of the fuselage structure, the dynamic response of the seat, the dynamic response of the passenger dummy and other data obtained from the crash test, to determine the correlation between the simulation result of the finite element model and the test result. When the correlation is poor, the material constitutive structure and failure criterion are corrected to improve the finite element model and thus improve the simulation accuracy, and finally obtain a verified fuselage frame section-seat-passenger crash analysis finite element model;

[0038] Step S3, typical fuselage frame section-seat-occupant crash response and occupant injury analysis: based on the verified fuselage frame section-seat-occupant crash analysis finite element model, a crash simulation under typical working conditions is performed to analyze the crash response of the civil aircraft fuselage frame section and the degree of occupant injury. According to the occupant injury assessment criteria, the occupant head and neck injuries, occupant lumbar spine injuries, and occupant femur injuries are assessed respectively to assess the comprehensive occupant injury;

[0039] Step S4, evaluating the crash response of the civil aircraft frame section and the injury degree of the occupants under the crash impact, based on the verified fuselage section-seat-occupant crash analysis finite element model, the crash response of the fuselage section and the injury degree of the occupants under the crash impact are evaluated, and according to the injury assessment criteria, the injury assessment of the occupants' head, neck, lumbar spine, femur, etc. is performed respectively.

[0040] Furthermore, the fuselage frame-seat-occupant crash analysis finite element model mainly includes three parts: a verified fuselage frame model, a verified seat restraint system model, and a calibrated occupant dummy model. The seat restraint system model includes an aviation seat model and a restraint system model.

[0041] Furthermore, the fuselage frame section model is mainly established using SECTION_SHELL shell elements and the Belytschko-Tsay algorithm; the fuselage material adopts an accurate material constitutive and failure model, and the fasteners adopt solid elements of 8 hexahedral clusters.

[0042] Furthermore, the aviation seat model is a typical three-seat passenger seat on an airliner, in which the components on the main force transmission path of the front and rear legs and support plates of the seat, the back cushion and the seat cushion assembly are modeled using SECTION_SOLID solid elements, and the thin-walled structures of the seat tubes, backrests and seat basins are simulated using SECTION_SHELL shell elements. The main load-bearing structural parts of the seat are three types of strain-rate insensitive aluminum alloy materials, using an elastoplastic material card with model number MAT 024-PIECEWISE LINEAR PLASTICITY, and the seat cushion is composed of two parts, polyurethane and polyethylene, using a low-density foam material card with model number MAT057-LOWDENSITYFOAM.

[0043] Furthermore, the restraint system model is a two-point seat belt and its anchor point. The seat belt adopts a mixed modeling method of one-dimensional SECTION_SEATBELT seat belt unit and two-dimensional SECTION_SHELL shell unit, and is connected using CNRB. The seat belt material is nylon. The 1D unit in the finite element model uses the MAT_B01-SEATBELT seat belt material card to simulate the fixation of the seat belt and the anchor point, and the 2D unit uses the MAT_034-FABRIC fabric material card to simulate the interaction between the seat belt and the occupant dummy.

[0044] Furthermore, the occupant dummy model is a fine simulation dummy of the Hybrid III 50th percentile male. The main components of this model of dummy include the head and neck, upper torso, pelvis, and lower torso. After being benchmarked with the physical dummy, the physical characteristics of each part are basically consistent with the corresponding physical dummy, and various sensors installed in the body can output the compression load of the femur, tibia and lumbar spine, and the head acceleration data, which has good bionics.

[0045] Furthermore, the fuselage frame section-seat-occupant crash analysis finite element model sets the contact definition between the various components, mainly including: the contact between the fuselage frame and the rigid impact plane, the self-contact of the fuselage frame, the contact between the seat system and the dummy, the contact between the restraint system and the dummy, and the contact between other components inside the seat system.

[0046] Furthermore, the fuselage frame-seat-occupant crash analysis finite element model performs crash simulation analysis, compares the deformation mode of the fuselage structure, the movement posture of the occupant dummy, and the loads borne by the head and lumbar spine of the occupant dummy to modify the model, and performs crash simulation under different crash postures, different crash speeds, different crash environments, different cargo loadings and other working conditions, to achieve a comprehensive analysis and evaluation of the crash response of the fuselage structure and occupant injuries.

[0047] Furthermore, the implementation process of the drop impact test is as follows: the theoretical vertical drop impact speed selected in the test is 20fps (6.10m / s), the test piece is vertically suspended with three-point symmetry, and the test piece is aligned with the center area of ​​the force measuring platform through the plumb line and the marking point on the force measuring platform. After confirming that the lifting height and the fuselage attitude angle are correct, the test piece is free-falling to make the instantaneous speed of the test piece reach the expected speed within the error range of ±5%, that is, 5.80m / s to 6.41m / s. According to the formula Where V is the expected contact velocity of 6.10m / s, the gravity acceleration g is 9.81m / s, the test piece should be lifted to a height of 1898mm and then released. The test process is mainly divided into three parts: pre-test preparation, formal test, and post-test inspection. The pre-test preparation includes test piece inspection, installation of dummies and sensors, test piece weighing and weight balancing, and system joint debugging. The formal test mainly involves lifting the test piece, confirming the fuselage posture before release, releasing the test piece after removing the protective device, and saving the test data and images. After the test, check the measurement data and high-speed camera image records for completeness and validity.

[0048] Furthermore, the collection of the crash test data includes the collection of seat rail acceleration data, fuselage velocity and displacement data, and response data of various parts of the dummy. The seat rail acceleration is measured by arranging 12 acceleration sensors at the cabin floor rails and at the connection between the legs of the two sets of seats, wherein the cabin floor longitudinal beams are numbered L1 to L8 from left to right. At the same time, acceleration sensors are arranged at the connection between each leg and the rail of the two sets of seats, and wires of sufficient length are reserved to measure the acceleration load of the rail at the seat legs. The fuselage velocity and displacement data are collected by arranging Mark points at the upper connecting trusses, cabin floor beams, cabin support columns, and cargo hold beams. A total of 35 Mark points are arranged on the fuselage frame section, numbered M1 to M35. By arranging high-speed cameras around the test platform, the motion trajectory of each Mark mark point during the crash can be obtained. Secondly, through data analysis and processing with TEMA3D software, the vertical velocity and displacement time history data of each key position of the fuselage frame section can be obtained. The response data of each part of the dummy is collected. The test arranges one Mark mark point on the head and knee of each of the four dummies, which are numbered M36 to M47 in sequence. Then, through data analysis and processing with high-speed cameras and TEMA3D software, the vertical velocity and displacement time history data of the head and knee of each dummy can be obtained. Secondly, through the lumbar load sensor and pelvic acceleration sensor built into the P1 and P4 dummies, the lumbar load and pelvic acceleration time history data of the two dummies can be obtained.

[0049] Furthermore, the experimental value of the injury criterion of the present invention is obtained by measuring an aviation dummy under an impact test, that is, the occupant injury of the impact test is measured using an aviation dummy, and the HIC value evaluates the occupant head injury. The occupant injury evaluation criterion refers to relevant regulations / standards, such as FAR25.562, FMVSS208, AC21-22, TSO-C127b, and AC25.562-1B.

[0050] Furthermore, the comprehensive injury assessment method is as follows: the occupant injury risk quantitative assessment indicators include:

[0051] Lumbar compression load of occupant: FL≤6,672N;

[0052] Compression load of left and right femur of occupant: FF≤10,008N;

[0053] Occupant head injury criterion: HIC≤1,000;

[0054] Occupant neck injury criterion: Nij≤1;

[0055] In addition, the present invention makes a comprehensive assessment of the occupant injury risk with reference to the concept of the comprehensive crashworthiness assessment index (ICI), and the assessment formula is:

[0056]

[0057] Among them, if the seat is always connected to the seat rail, Attach=1, otherwise Attach=0; if the seat deformation does not affect the emergency evacuation of the occupant, Seat=1, otherwise Seat=0; if the seat belt remains restrained at the pelvis of the occupant, Restraint=1, otherwise Restraint=0.

[0058] Experimental example

[0059] This experimental example is based on the verified fuselage section-seat-occupant crash analysis finite element model to evaluate the dynamic response and injury analysis of the occupants under different crash conditions. The different crash conditions include different crash postures, different crash speeds, and different crash environments. The present invention only takes different crash postures as examples, and selects left and right roll angles of 3°, 6°, and 9°, respectively, to study the dynamic response and injury degree of the occupants corresponding to different pitch angles at a vertical impact speed of 6.01 m / s.

[0060] According to the value of the acceleration sensor, a line graph of the relationship between the seat guide rail acceleration peak and the turning angle was obtained, and it was concluded that: the overload at the left guide rail when rolling to the right is generally higher than that at the right side, and the lumbar load level of each occupant shows a trend of first increasing and then decreasing with the increase of the angle, and the lumbar load is highest at a rolling angle of about 3°; the lumbar load level of the occupant in a downward pitch angle crash is generally higher than that in an upward pitch angle crash condition, and the lumbar load level of each occupant shows a trend of first increasing and then decreasing with the increase of the angle, and the lumbar load is highest at a pitch angle of about 3° / 6°.

[0061] In summary, the analysis and evaluation method of the present invention can evaluate the crash response of civil aircraft frame sections and occupant injuries.

[0062] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An analysis and evaluation method for the crash response of a typical fuselage frame section of a civil aircraft and occupant injury, characterized by: It includes establishing a typical fuselage frame section-seat-occupant crash analysis finite element model for civil aircraft, verifying a typical fuselage frame section-seat-occupant crash analysis finite element model, conducting fuselage frame section-seat-occupant crash response and occupant injury analysis under typical crash conditions, and conducting analysis and evaluation of civil aircraft frame section crash response and occupant injury under various crash conditions. The specific steps are as follows: Step S1, establishing a typical fuselage frame section-seat-occupant crash analysis finite element model for civil aircraft: respectively establishing a verified fuselage frame section structure finite element model and a seat / occupant restraint system finite element model, combining the fuselage frame section structure finite element model and the seat / occupant restraint system finite element model to establish a typical fuselage frame section-seat-occupant crash analysis finite element model for civil aircraft; Step S2, verifying a typical fuselage frame section-seat-passenger crash analysis finite element model for civil aircraft: first, using the above model calculation to solve the simulation result of the fuselage frame section-seat-passenger crash analysis finite element model, and comparing it with the crash response of the fuselage structure, the dynamic response of the seat, the dynamic response of the passenger dummy and other data obtained from the crash test, to determine the correlation between the simulation result of the finite element model and the test result. When the correlation is poor, the material constitutive structure and failure criterion are corrected to improve the finite element model and thus improve the simulation accuracy, and finally obtain a verified fuselage frame section-seat-passenger crash analysis finite element model; Step S3, performing a crash response and occupant injury analysis of a fuselage frame section, seat, and occupant under a typical crash condition: performing a crash simulation under a typical condition based on a verified finite element model for a crash analysis of a fuselage frame section, seat, and occupant, analyzing the crash response of a civil aircraft fuselage frame section and the degree of occupant injury, and evaluating the occupant's head and neck injuries, occupant's lumbar spine injuries, and occupant's femur injuries according to an occupant injury assessment criterion, respectively, to assess the comprehensive occupant injury; Step S4, analyzing and evaluating the crash response of typical fuselage frames of civil aircraft and occupant injuries under different crash conditions: based on the verified fuselage frame-seat-occupant crash analysis finite element model, considering different crash conditions and different cargo loading conditions, etc., crash simulations are performed under various crash conditions, and the crash response degree of the fuselage section and the injury degree of the occupants under the crash impact are analyzed and evaluated. According to the injury assessment criteria, the injury assessment of the occupant's head, neck, lumbar spine, femur, etc. is performed respectively.

2. The method for analyzing and evaluating the crash response of a typical fuselage frame section of a civil aircraft and the injury to the occupants according to claim 1 is characterized by: The fuselage frame-seat-occupant crash analysis finite element model mainly includes three parts: a verified fuselage frame model, a verified seat restraint system model, and a calibrated occupant dummy model. The seat restraint system model includes an aviation seat model and a restraint system model.

3. The method for analyzing and evaluating the crash response of a typical fuselage frame section of a civil aircraft and the injury to the occupants according to claim 2 is characterized by: The fuselage frame section model is mainly established using SECTION_SHELL shell elements and the Belytschko-Tsay algorithm; the fuselage material adopts an accurate material constitutive and failure model, and the fasteners adopt solid elements of 8 hexahedral clusters.

4. The method for analyzing and evaluating the crash response of a typical fuselage frame section of a civil aircraft and the injury to the occupants according to claim 2 is characterized by: The aviation seat model is a typical three-seat passenger seat on an airliner, in which the components on the main force transmission path of the front and rear legs and support plates of the seat, the back cushion and the seat cushion assembly are modeled using SECTION_SOLID solid elements, and the thin-walled structures of the seat tube, back and seat basin are simulated using SECTION_SHELL shell elements. The main load-bearing structural parts of the seat are three strain-rate insensitive aluminum alloy materials, using an elastoplastic material card with model number MAT 024-PIECEWISE LINEAR PLASTICITY, and the seat cushion is composed of two parts, polyurethane and polyethylene, using a low-density foam material card with model number MAT057-LOW DENSITYFOAM.

5. The method for analyzing and evaluating the crash response of a typical fuselage frame section of a civil aircraft and the injury to the occupants according to claim 2 is characterized by: The restraint system model is a two-point seat belt and its anchor point. The seat belt adopts a mixed modeling method of one-dimensional SECTION_SEATBELT seat belt unit and two-dimensional SECTION_SHELL shell unit, and is connected using CNRB. The seat belt material is nylon. The 1D unit in the finite element model uses the MAT_B01-SEATBELT seat belt material card to simulate the fixation of the seat belt and the anchor point, and the 2D unit uses the MAT_034-FABRIC fabric material card to simulate the interaction between the seat belt and the occupant dummy.

6. The method for analyzing and evaluating the crash response of a typical fuselage frame section of a civil aircraft and the injury to the occupants according to claim 2 is characterized by: The passenger dummy model is a fine simulation dummy of a Hybrid III 50th percentile male. Various sensors installed in the dummy can output compression loads of the femur, tibia and lumbar spine, and acceleration data of the head, and has good bionics.

7. The method for analyzing and evaluating the crash response of a typical fuselage frame section of a civil aircraft and the injury to the occupants according to claim 1, characterized in that: The fuselage frame-seat-occupant crash analysis finite element model sets the contact definition between the various components, mainly including: the contact between the fuselage frame and the rigid impact plane, the self-contact of the fuselage frame, the contact between the seat system and the dummy, the contact between the restraint system and the dummy, and the contact between other components inside the seat system.

8. The method for analyzing and evaluating the crash response of a typical fuselage frame section of a civil aircraft and the injury to the occupants according to claim 1 is characterized by: The fuselage frame-seat-occupant crash analysis finite element model performs crash simulation analysis, compares the deformation mode of the fuselage structure, the movement posture of the occupant dummy, and the load borne by the head and lumbar spine of the occupant dummy to modify the model, and performs crash simulation under different crash postures, different crash speeds, different crash environments, different cargo loadings and other working conditions to achieve a comprehensive analysis and evaluation of the crash response of the fuselage structure and occupant injuries.

9. The method for analyzing and evaluating the crash response of a typical fuselage frame section of a civil aircraft and the injury to the occupants according to claim 1, characterized in that: The occupant injury risk quantitative assessment indicators include: Lumbar compression load of occupant: FL≤6,672N; Compression load of left and right femur of occupant: FF≤10,008N; Occupant head injury criterion: HIC≤1,000; Occupant neck injury criterion: Nij≤1; In addition, the present invention makes a comprehensive assessment of the occupant injury risk with reference to the concept of the comprehensive crashworthiness assessment index (ICI), and the assessment formula is: Among them, if the seat is always connected to the seat rail, Attach=1, otherwise Attach=0; if the seat deformation does not affect the emergency evacuation of the occupant, Seat=1, otherwise Seat=0; if the seat belt remains restrained at the pelvis of the occupant, Restraint=1, otherwise Restraint=0.

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