A digital evaluation model of a car with the body posture of the 95th percentile of Chinese males, a model construction method and application

Abstract

The application discloses a kind of automobile digitization evaluation models with Chinese sign 95th percentile male sign, the model is simulated by a variety of finite element grid unit to human tissue, give different material properties, with detailed human anatomy structure features are optimized, splice different tissue structure, obtain the model.The application also discloses the construction method of the above-mentioned model, comprising: by collecting the CT data of Chinese 95th percentile male sign to construct human geometry model, form hexahedron unit structure by finite element grid division, correct the physiological curvature of spine and construct intervertebral disc, annulus fibrosus etc., after being connected to form standing posture model by tendon, adjust posture according to passenger sitting posture angle and optimize muscle grid, finally integrate each tissue structure to form passenger posture automobile digitization evaluation model with Chinese 95th percentile male sign.The application has wide application value.

Description

Technical Field

[0001] This invention belongs to the fields of human body numerical calculation model development technology and automotive safety technology research and development, crash testing and safety system optimization technology, and relates to a digital evaluation model of vehicle occupant posture with the 95th percentile male physical characteristics in China, the model construction method and application. Background Technology

[0002] Research on occupant injury mechanisms in the field of automotive crash safety can be categorized into several typical methods: cadaver experiments, volunteer experiments, anthropometric test devices (ATDs), and digital human models. Cassaver and volunteer experiments are limited by difficulties in sample acquisition and ethical concerns, resulting in a scarcity of publicly available literature. Currently, ATDs and digital human models are primarily used to study human injuries in automotive crashes. ATDs are physical dummies, typically constructed of plastic and metal, that simulate the shape and movement of the human body to assess occupant safety and potential injury during crash tests. In contrast, digital human models are computer-generated virtual models based on anatomical data and biomechanical principles, better simulating the forces and deformations of the human body during a crash. While ATD test results are more intuitive, limitations in model design and materials prevent them from fully reflecting the impact of different body shapes or weights on test results. Digital human models, however, can be customized by adjusting parameters to generate virtual models of various body types for simulation calculations, thus improving the flexibility of model use and reducing experimental costs.

[0003] There are two types of digital human body models. One is the multi-rigid-body model, which can calculate the kinematic response of the human body model in a shorter CPU time. The other is the finite element human body model. Compared with the above models, the finite element human body model can more accurately describe the anatomical structure of the human body, such as bones, internal organs, muscles and other soft tissues. It can effectively assess the human body's collision response and injury-related local variables. For example, the finite element model can predict complex chest deformation and fractures.

[0004] Currently, several versions of finite element models of the human body have been developed abroad, but most of these models are scaled down from the 50th percentile male model. These models are designed and developed based on European and American anthropometric standards. However, there are significant differences between Chinese and European / American anthropometric dimensions. Therefore, using anthropometric models based on European and American standards to assess the injury risk of Chinese occupants in car crashes is inaccurate. Furthermore, the New Car Assessment Programme (NCAP) of various countries primarily selects the 50th percentile male occupants of medium build and the 5th percentile female occupants of small build as test subjects, neglecting the testing of the 95th percentile male occupants of large build. Given the diversity of body types in the modern population, the limitations of this testing method are becoming increasingly apparent, especially in assessing the potential collision risks faced by large-build occupants. To more comprehensively assess occupant injury in car crashes, it is necessary to develop diverse finite element models. These models should comprehensively consider differences in gender and body type. Therefore, based on CT images of the 95th percentile male volunteers, a biomimetic model of injury for the 95th percentile male car occupant, conforming to Chinese physical characteristics, is being developed to study the injury mechanism of large-build male occupants. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a digital assessment model (also known as a biomechanical model) with physical characteristics of the 95th percentile of Chinese males, a model construction method, and its application.

[0006] This invention provides a digital assessment model of a car's occupant posture based on the physical characteristics of a Chinese male at the 95th percentile, also known as a biomechanical model. This model serves as a digital computational tool in the field of automotive collision safety. The digital assessment model or biomechanical model described in this invention conforms to the latest anthropometric statistics from the China National Institute of Standardization, showing the physical characteristics of a Chinese male at the 95th percentile. The model's weight is 85.3 kg, sitting height is 99.9 cm, shoulder width is 41.5 cm, maximum shoulder width is 49.4 cm, chest thickness is 25.6 cm, chest width is 31.8 cm, and the model has 1.536 million elements and 1.203 million nodes. The model possesses detailed anatomical features, including bones, muscles, internal organs, fat, soft tissues, ligaments, tendons, and skin. The model uses hexahedral elements, quadrilateral shell elements, a small number of pentahedral elements, and / or triangular shell elements for simulation based on different structures and parts of the human body. Specifically, cancellous bone, muscles, internal organs, fat, and soft tissues are simulated using hexahedral elements; compact bone, muscles, internal organs, fat, and soft tissues are simulated using hexahedral elements; and compact bone, muscles, internal organs, fat, and soft tissues are simulated using cortical elements. Ligaments, joint capsules, muscle fascia, visceral organ membranes, and skin are constructed using quadrilateral shell elements; some ligaments and tendons are constructed using pentahedral and triangular shell elements; the various tissue structures are connected using a shared-node approach; the tissue structures in the model are assigned corresponding material properties based on their different mechanical characteristics, and contact is defined according to the tissue structure relationships; specifically, the *CONTACT_AUTOMATIC_SINGLE_SURFACE keyword is selected to define the self-contact between the various tissue structures in the model, the *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE keyword is selected to define the contact between joints in the model, and the DATABASE_CROSS_SECTION_PLANE keyword is selected to define the cross-section of the spinal finite element model;

[0007] In particular, this invention optimizes the construction of the heart, sacrum, and hip bone structures. It uses pure hexahedral units to construct a heart structure including the left atrium, right atrium, left ventricle, right ventricle, pulmonary artery, aorta, superior vena cava, and inferior vena cava; a sacral structure including the sacral canal, anterior sacral foramen, and posterior sacral foramen; and a hip bone structure including the acetabulum, obturator foramen, pubic tubercle, ischial tuberosity, iliac body, and iliac wing.

[0008] The model described in this invention has a high degree of biosimulation and can be used to conduct biomechanical studies on large male car occupants in collisions. The content of this invention is applicable to multiple fields such as medicine, engineering, sports science, product design, and emergency rescue.

[0009] This invention proposes a method for constructing a digital evaluation model of vehicle occupant posture based on the physical characteristics of the 95th percentile male in China with detailed anatomical structure. The specific steps of the construction method are as follows:

[0010] Step A: Based on the latest physical characteristics statistics measured by the China National Institute of Standardization, CT image data of volunteers who meet the physical characteristics of the 95th percentile of males in China were acquired multiple times. Based on the CT data, a human geometric model was reconstructed, including bones, muscles, internal organs, soft tissues, and skin. The human geometric model can be divided into rectangular geometric models, trapezoidal geometric models, and columnar geometric models according to their shapes.

[0011] Step B: Perform finite element mesh generation on the geometric model obtained in Step A to construct finite element models of various tissue structures, including the heart, sacrum, hip bone, and spine.

[0012] Specifically, for the heart structure in the model, a hexahedral finite element mesh (hexahedral elements) was used to construct structures including the left atrium, right atrium, left ventricle, right ventricle, pulmonary artery, aorta, superior vena cava, and inferior vena cava; for the sacral structure in the model, a hexahedral finite element mesh was used to construct structures including the sacral canal, anterior sacral foramen, and posterior sacral foramen; for the hip structure in the model, a hexahedral finite element mesh was used to construct structures including the acetabulum, obturator foramen, pubic tubercle, ischial tuberosity, iliac body, and iliac wing; for the spinal structure in the model, a hexahedral finite element mesh was used to construct structures including vertebral bodies, intervertebral discs (nucleus pulposus, annulus fibrosus), and spinal cord, and quadrilateral shell elements were used to construct ligaments (ligamentum flavum, anterior longitudinal ligament, posterior longitudinal ligament, interspinous ligament, and supraspinous ligament).

[0013] Step C: For the finite element model of the spine constructed in Step B, correct the physiological curvature of the spine according to the normal physiological curvature of the human spine, and construct the intervertebral discs, nucleus pulposus, annulus fibrosus, and ligaments; select the nodes of the annulus fibrosus at different positions on the hexahedral mesh using the "Move" command, and move them at a certain distance along the offset direction of the node perimeter to simulate the arc-shaped structure of the outer surface of the annulus fibrosus; specifically, the average offset distance of the annulus fibrosus in the cervical spine is 0.6-0.8 mm; the average offset distance of the annulus fibrosus in the thoracic spine is 0.8-1.0 mm; and the average offset distance of the annulus fibrosus in the lumbar spine is 1.0-1.2 mm.

[0014] Step D: Connect the finite element models of each tissue structure constructed in Step B and the finite element model of the spine with adjusted physiological curvature constructed in Step C through tendons and ligaments to form the finite element model of the standing posture of the 95th percentile male in China's physical characteristics.

[0015] Step E: Adjust the standing posture finite element model obtained in step D to the occupant posture based on the normal sitting posture angle range, and reverse optimize and adjust the muscle mesh division.

[0016] Step F: Connect the organizational structures of each part of the finite element model of a Chinese male with the 95th percentile of physical characteristics, which has been adjusted to the occupant posture, and finally obtain a digital evaluation model of the occupant posture of the car with the physical characteristics of a Chinese male with the 95th percentile of physical characteristics.

[0017] In this invention, the reconstruction of the human body geometric model in step A includes the following sub-steps:

[0018] Step A1: In Mimics software, geometric extraction of structures including bones, fat, skin, internal organs, and muscles is performed using different grayscale value ranges, and 3D models are generated.

[0019] Specifically, in Mimics software, bones, fat, skin, muscles, and internal organs are geometrically extracted according to different grayscale value ranges and 3D models are generated. Specifically, the grayscale value range of bones is [148, 661], fat is [-51, 205], skin is [-718, -177], muscles are [-5, 135], and internal organs are [-178, 146].

[0020] Step A2: For the generated 3D model, in Mimics software, use the "Smooth" command to define a smoothing coefficient of 0.6, the "Reduce" command to define a tolerance of 1mm, an edge angle of 10°, and the "Wrap" command to define a gap closure distance of 5mm. By applying the "Smooth", "Reduce", and "Wrap" commands to the surface of the geometric model, the error generated by the geometric model on the finite element model can be significantly reduced, improving the overall accuracy and reliability of the model. The model is then output in *.STL file format.

[0021] Step A3: Import the *.STL file obtained in Step A2 into Geomagic software and perform operations on the geometric model, including thinning, fast smoothing, relaxation, removal of spikes, and feature removal; process the uneven parts of the geometric model's edges through repair and trimming; use the "Bridge" command under the "Fill Holes" module to repair holes, making them conform to human anatomical structure; to effectively reduce the errors generated during the mutual penetration of geometric models, optimize their geometry by performing Boolean operations on two adjacent geometric models; for the smoothed geometric model, divide it into surface patches according to its shape and construct a grid, finally fitting it as a NURBS surface and converting it into a CAD model, outputting it in *.SAT file format.

[0022] In this invention, the finite element mesh generation method in step B includes the following sub-steps:

[0023] Step B1: Import the geometric model processed in Step A into ANSA software in *.SAT format;

[0024] Step B2: For the rectangular geometric model, use the "Hexahedral-box" method. In the "HEXA BLOCK" module, use the "Boxes" command to create a "Box" for the entire geometric model. Divide the "Box" according to the distribution of the surface patches. Move the nodes on the "Box" to the intersection of the contour lines on the surface patches, and then perform point-to-point and line-to-line matching.

[0025] And / or,

[0026] For trapezoidal geometric models, the "Hexahedral-box-box" method is used, which involves creating "Boxes" by segmenting the geometric model based on surface patches, and then using the "Paste" command to fit the corresponding faces of two adjacent "Boxes" face-to-face, so that the "Boxes" share edges.

[0027] And / or,

[0028] For columnar geometric models, the "O-Grid structure", also known as the "butterfly grid", is used. The "O-Grid" command is used to select the frame that is already attached to the "Box" and offset it inward to construct an orthogonal structure (butterfly structure).

[0029] Step B3: To ensure a high-quality finite element mesh, a "layered meshing" method is adopted. The mesh density inside the geometric model is increased by uniformly dividing the length, width, and height regions that have been fitted to the "Box", so as to constrain the distribution of the internal mesh.

[0030] Step B4: According to the grid size requirements, set the grid number for the edge that has been fitted to the "Box" using the "Number" command; in one specific implementation, the grid size requires the maximum unit size to not exceed 12mm and the minimum unit size to not exceed 1mm. The size will be adjusted according to the actual situation to better meet the actual needs.

[0031] Step B5: Using the “Volume Mesh” command, perform pure hexahedral meshing on the entire fitted “Box”. Smooth the constructed hexahedral mesh to reduce uneven distribution of the internal mesh, thus completing the hexahedral meshing of the geometric model.

[0032] In this invention, step C, the correction and construction of the physiological curvature of the spine, includes the following sub-steps:

[0033] Step C1: Based on the normal physiological curvature image of the spine, use the point-plotting method to select points on the upper, middle, and lower regions of the anterior surface of the 24 vertebrae and the upper surface of the anterior surface of the sacrum along the midsagittal plane of the human body, and connect the selected 73 points with spline curves to obtain the normal physiological curvature curve of the spine.

[0034] Step C2: Import the obtained normal spinal physiological curvature curve into ANSA software and scale it so that the spinal physiological curvature curve is the same size as the spinal finite element model.

[0035] Step C3: Using the sacrum as a reference, align the sacral point at the end of the normal physiological curvature curve of the spine with the sacrum. Then, translate and rotate each vertebra individually to align it with the point on the curve, and finally obtain the physiological curvature of the spine of the 95th percentile male in China.

[0036] Step C4: Use the "Elements" command under the "MESH" module to complete the construction of the intervertebral disc between each adjacent upper and lower vertebral body; use the "Solid Builder" command to construct the annulus fibrosus around the edge of the constructed intervertebral disc, with the lower surface of the upper vertebral body and the upper surface of the lower vertebral body as the boundary; then use the "Move" command to move the nodes on the finite element mesh of the annulus fibrosus to simulate the arc-shaped structure of the outer surface of the annulus fibrosus.

[0037] Step C5: By constructing a quadrilateral mesh to simulate the structures between vertebrae, including facet joint capsules, articular cartilage, interspinous ligaments, supraspinous ligaments, transverse ligaments, ligamentum flavum, anterior longitudinal ligament, and posterior longitudinal ligament, a finite element model of the male spine at the 95th percentile that conforms to normal physiological curvature is obtained.

[0038] In this invention, the construction of the finite element model of the standing posture of the 95th percentile male in China in step D includes the following sub-steps:

[0039] Step D1: Using the head finite element model as a reference, connect the spine finite element model after correction and construction in step C with the head finite element model;

[0040] Step D2: Adjust and connect the rib finite element model according to the human anatomical structure. The connection between muscles and bones is simulated using 2D shell elements and pentahedrons.

[0041] Step D3: Symmetrically model the upper and lower limbs along the midsagittal plane of the human body, and connect them to the corresponding bones through ligaments and tendons;

[0042] Step D4: Import the smoothed skin geometry model into ANSA software. Construct the fat using "Projection" to obtain the finite element model of the 95th percentile male standing posture in China. The specific operation of "Projection" is as follows: Use the "Extrude" command to select the area to be projected, then select the skin structure as the boundary condition, and finally combine the "Offset" and "Guidelines" commands to project the fat.

[0043] In this invention, step E, adjusting the sitting posture of the 95th percentile male passenger in China, includes the following sub-steps:

[0044] Step E1: Using the pelvic structure, namely the sacrum, hip bones, coccyx, etc., as a reference, adjust the 95th percentile male standing posture finite element model to the occupant posture.

[0045] Step E2: Adjust the body angles of the 95th percentile male finite element model according to the normal sitting posture angle range of the occupant; specifically, adjust the corresponding upper arm angle, forearm angle, backrest angle, torso angle, knee angle, and ankle angle according to the rotation centers of the shoulder joint, elbow joint, wrist joint, hip joint, knee joint, and ankle joint; the normal sitting posture range includes: upper arm angle 0°~30°, forearm angle 120°~160°, backrest angle 20°~30°, torso and thigh angle 95°~115°, knee angle 100°~145°, and ankle angle 87°~110°;

[0046] Step E3: Correct and connect the finite element model of the muscle in the seated position; for muscle structures with large deformation, such as the gluteus maximus, rectus femoris, long head of biceps femoris, lateral head of gastrocnemius, and medial head of gastrocnemius, a reverse engineering method is used to ensure the quality of the finite element mesh: generate shell elements on the deformed surface of the structure and output them in *.STL file format, import them into Geomagic software to re-mesh the surface patches, and finally import them into ANSA software to re-mesh the mesh.

[0047] In step F, the finite element model adjusted to the occupant posture in step E is connected, mainly including the tendons, ligaments, fat and skin at the shoulder joint, elbow joint, hip joint and knee joint, and finally obtains a digital evaluation model of the car with the physical characteristics of a male at the 95th percentile of Chinese physical characteristics.

[0048] This invention also proposes a digital vehicle evaluation model based on the above method, which features the physical characteristics of a Chinese male at the 95th percentile. The model's characteristic dimensions conform to the anthropometric statistics of the China National Institute of Standardization. The model weighs 85.3 kg, has a sitting height of 99.9 cm, a shoulder width of 41.5 cm, a maximum shoulder width of 49.4 cm, a chest thickness of 25.6 cm, a chest width of 31.8 cm, 1.536 million units, and 1.203 million nodes. The model has a detailed anatomical structure, and corresponding material properties are assigned to different tissue structures to give the model mechanical properties.

[0049] The digital evaluation model selects the keyword *CONTACT_AUTOMATIC_SINGLE_SURFACE to define the self-contact between the tissue structures in the model, selects the keyword *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE to define the contact between joints in the model, and selects the keyword DATABASE_CROSS_SECTION_PLANE to define the cross-section of the spinal finite element model.

[0050] The digital evaluation model can effectively reflect biomechanical characteristics in both local (head, neck, upper limbs, lower limbs, pelvis) and whole-person verification tests, and can effectively reflect fractures, craniocerebral and visceral injuries. The digital evaluation model can be applied to the evaluation of occupant protection in automobile collision safety performance testing and new car evaluation procedures, filling the gap in the evaluation of injuries to large male occupants.

[0051] The digital assessment model is applicable to multiple fields, including medicine, engineering, sports science, product design, and emergency rescue. Specifically, it covers areas such as automotive design and safety research, road traffic accident research, medical research and medical device design, and emergency rescue implementation. By simulating the natural response mechanisms of organisms to injury, the model provides a deeper understanding of injury mechanisms, thereby offering innovative solutions for various application areas. Specifically, in the medical field, the model can guide the development of new treatment plans and improve patient rehabilitation outcomes. In engineering, human-adaptive design methods can develop more robust and safer materials and structures. In sports science, the model helps athletes develop personalized training plans and reduce injury risks. In product design, the model promotes the development of more ergonomic products. In emergency rescue, simulating the reactions of organisms in emergencies optimizes rescue strategies and improves rescue efficiency. Through interdisciplinary collaboration and innovation, the model can improve human quality of life and safety.

[0052] The beneficial effects of this invention include: The construction of a digital evaluation model for automobiles based on the physical characteristics of the 95th percentile male in China fills the gap in the construction of finite element models of the 95th percentile male occupants in China. Compared with digital models developed abroad, the anatomical characteristics are more obvious, the biosimulation is higher, and it can more accurately judge different stress and strain conditions and damage conditions of the human body. It can provide basic data and technical support for automobile digital evaluation technology, integrated research on active and passive safety of automobiles, and the development of safety protection devices. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This invention provides a construction method and application flowchart for a digital evaluation model of automobiles with the physical characteristics of the 95th percentile male in China.

[0055] Figure 2 The diagram shows a Boolean operation on a geometric model; where (a) is the original geometric model, (b) is the geometric model after the Boolean operation, and (c) is the geometric model after smoothing.

[0056] Figure 3 This diagram illustrates the hexahedral finite element mesh generation of a trapezoidal geometric model using the "Hexahedral-box-box" method. (a) shows the processed geometric model with outlines, (b) shows a "Box" constructed based on the segmented outer contour of the geometric model, (c) shows two "Boxes" fitted face-to-face, (d) shows the fitted "Box", (e) shows the number of meshes on each side of the "Box", and (f) shows the hexahedral finite element mesh.

[0057] Figure 4 A schematic diagram of the "layered mesh" method to improve the quality of finite element meshes; where (a) is the "Box" geometric model that has been fitted, (b) is the internal mesh distribution of the finite element without using the "layered mesh" method, (c) is the uniform division of adjacent sides of the "Box", (d) is the internal node distribution, and (e) is the internal mesh distribution of the finite element with the "layered mesh" method.

[0058] Figure 5 This is a schematic diagram of spinal physiological curvature correction; where (a) is the spinal physiological curvature before correction, (b) is the normal physiological curvature curve of the spine in the 95th percentile of Chinese males, and (c) is the spinal physiological curvature after correction.

[0059] Figure 6 This is a schematic diagram of a hexahedral heart structure. The heart structure includes: left atrium, right atrium, left ventricle, right ventricle, pulmonary artery, aorta, superior vena cava, and inferior vena cava.

[0060] Figure 7 This is a schematic diagram of the hexahedral pelvic structure; where (a) is the sacral structure, (b) is the hip structure, and (c) is a sectional view of the sacrum.

[0061] Figure 8 Determining the rotation axes of various body parts for occupant posture adjustment; including (a) upper torso rotation axis, (b) lower limb rotation axis, (c) lower leg rotation axis, (d) foot rotation axis, (e) upper limb rotation axis, and (f) elbow joint rotation axis.

[0062] Figure 9 The diagram shows the muscle shape correction; (a) is the finite element model before correction, (b) is the "Box" constructed for the deformed region, (c) is the finite element model after deformation, (d) is the new geometric model after the reverse operation, (e) is the surface patch division of the new geometric model, and (f) is the finite element model after correction.

[0063] Figure 10 This is a schematic diagram of the digital evaluation model of the physical characteristics of Chinese males at the 95th percentile according to the present invention; wherein, (a) is a front view and (b) is a side view.

[0064] Figure 11 This is a schematic diagram illustrating the combination of a digital evaluation model of the physical characteristics of the 95th percentile male in China with a car seat, as described in an embodiment of the present invention.

[0065] Figure 12 This is a schematic diagram of the acceleration of various parts of the body in the digital evaluation model of the physical characteristics of a male in the 95th percentile of China according to an embodiment of the present invention; wherein (a) is the acceleration of the head, (b) is the acceleration of the T1 thoracic vertebra, (c) is the acceleration of the T8 thoracic vertebra, and (d) is the acceleration of the pelvis. Detailed Implementation

[0066] The present invention will be further described in detail below with reference to the specific embodiments and accompanying drawings. Except for the contents specifically mentioned below, the processes, conditions, and experimental methods for implementing the present invention are all common knowledge and general knowledge in the art, and the present invention does not have any particular limitations.

[0067] The digital vehicle evaluation model (also known as a biomechanical model) based on the physical characteristics of the 95th percentile male in China proposed in this invention is constructed based on CT medical imaging data of the 95th percentile male volunteers in China. The model's characteristic dimensions conform to the anthropometric statistics of the China National Institute of Standardization. The model's weight is 85.3 kg, sitting height is 99.9 cm, shoulder width is 41.5 cm, maximum shoulder width is 49.4 cm, chest thickness is 25.6 cm, chest width is 31.8 cm, the number of elements is 1.536 million, and the number of nodes is 1.203 million. The model has a detailed anatomical structure, including structures such as bones, muscles, internal organs, fat, soft tissues, ligaments, tendons, and skin. The model uses hexahedral elements, quadrilateral shell elements, and a small number of pentahedral elements and triangular shell elements for simulation, and the various tissue structures are connected by sharing nodes. The tissue structures in the model are assigned corresponding material properties according to their different mechanical characteristics.

[0068] The digital assessment model described in this invention has a high degree of biosimulation and can be used to conduct biomechanical research on car occupants with the physical characteristics of the 95th percentile male in China during collisions. The digital car assessment model based on the physical characteristics of the 95th percentile male in China proposed in this invention fills a gap in domestic research on the injury mechanisms of large-statured male occupants and can be used for integrated research on active and passive safety in automobiles, as well as digital car assessment.

[0069] This invention provides a method for constructing the above-mentioned digital assessment model, such as... Figure 1 As shown, it includes the following steps:

[0070] (1) Geometric model reconstruction method.

[0071] Based on the latest vital sign statistics measured by the China National Institute of Standardization, CT image data of volunteers conforming to the 95th percentile of male physical characteristics in China were acquired multiple times. Using Mimics software, a human geometric model, including bones, muscles, internal organs, soft tissues, and skin, was accurately extracted. The "Smooth," "Reduce," and "Wrap" commands were used to define smoothing coefficients, tolerances, edge angles, and gap closure distances. This preprocessing step aimed to significantly reduce the errors introduced by the geometric model into the finite element model, improving the overall model's accuracy and reliability. By appropriately setting these parameters, this invention can optimize the smoothness of the geometric surface, ensuring better performance and accuracy of the model in subsequent analysis and applications.

[0072] The geometric model is imported into Geomagic software. During the polygon stage, the surface of the geometric model is smoothed using commands such as thinning, fast smoothing, relaxation, removing spikes, and removing features. To ensure that the edge curvature of the geometric model more closely matches the true anatomical structure, the uneven parts of the edges are repaired and trimmed: the selected area mesh is deleted, and the "Curvature" and "Bridge" options in the "Fill Hole" command are used to select and delete the surrounding mesh of the selected area, making the curvature of the new mesh match the curvature of the surrounding mesh. To effectively reduce the error caused by the interpenetration of geometric models, Boolean operations are performed on two adjacent geometric models to optimize their geometry. Specifically, first, two adjacent geometric models are selected, such as... Figure 2 As shown in (a), a subtraction operation is performed to eliminate geometric errors caused by model overlap, while ensuring that the original object remains unchanged and is available for subsequent processing. After subtraction, the newly generated geometric model is as follows. Figure 2 As shown in (b), the surface is uneven and the mesh curvature is abnormal, requiring further processing through the polygon stage, including surface smoothing, to improve the overall geometric quality. The processed geometric model is as follows. Figure 2 As shown in (c), in the precise surface stage, firstly, preliminary surface patches are created on the geometric model using drawing commands. Then, the shapes of these surface patches are adjusted using relaxation commands to achieve the required smoothness and continuity. Based on this, split / merge commands are used to handle complex geometric structures, making the connections between surface patches more reasonable. Furthermore, subdividing the curves helps increase the resolution of the surface patches, thereby improving the surface detail. Finally, commands such as shrink are used to optimize the constructed grid to ensure accurate surface fitting. The final generated surface data is fitted as a NURBS (Non-Uniform Rational B-Spline) surface, ensuring high controllability and flexibility through this standardized format. Finally, the generated surface is converted into a CAD model and output as a *.SAT file.

[0073] (2) Finite element model construction method.

[0074] The reconstructed human body geometric model can be categorized by shape into rectangular, trapezoidal, and columnar geometric models. Specifically, the rectangular geometric model includes the ribs, costal cartilages, clavicle, maxilla and mandible, trapezium, trapezium, capitate, hamate, pisiform, triquetrum, lunate, scaphoid, metacarpals, proximal phalanges, middle phalanges, distal phalanges, medial cuneiform, intermediate cuneiform, lateral cuneiform, cuboid, navicular, talus, calcaneus, patella, heart, liver, spleen, pancreas, kidneys, stomach, large intestine, small intestine, bladder, prostate, trachea, esophagus, and blood vessels. The trapezoidal geometric model includes the sternum, scapula, sacrum, hip bones, cervical vertebrae (C1-C7), thoracic vertebrae (T1-T12), and lumbar vertebrae (L1-L5). The columnar geometric model includes the humerus, ulna, radius, femur, tibia, fibula, and lungs. Muscles in different parts of the body can also be classified according to these three types.

[0075] In this invention, specifically, a hexahedral finite element mesh (hexahedral elements) is used to construct the heart structure in the model, including structures such as the left atrium, right atrium, left ventricle, right ventricle, pulmonary artery, aorta, superior vena cava, and inferior vena cava, as shown below. Figure 6 As shown; for the sacral structure in the model, a hexahedral finite element mesh was used to construct structures including the sacral canal, anterior sacral foramen, and posterior sacral foramen; for the hip structure in the model, a hexahedral finite element mesh was used to construct structures including the acetabulum, obturator foramen, pubic tubercle, ischial tuberosity, iliac body, and iliac wing, as shown. Figure 7 As shown.

[0076] For rectangular geometric models, the "Hexahedral-box" method is used. This involves constructing an initial "Box" matching the rectangular geometric model using the "Boxes" command within the "HEXA BLOCK" module. Then, based on the geometric distribution of the surface patches, the "Box" is appropriately divided into multiple sub-blocks. Subsequently, the nodes on the "Box" are moved to positions near their corresponding geometric nodes, ensuring that the nodes of the "Box" model are highly aligned with the geometric features of the original geometric model. For trapezoidal geometric models, the "Hexahedral-box-box" method is used. First, as shown... Figure 3 As shown in (a), the surface patches of the trapezoidal geometric model are analyzed segment by segment. Based on their geometric features and the shape of the patches, the entire model is rationally divided into several sub-regions. For each sub-region, a corresponding "Box" is independently created to ensure that each "Box" can accurately cover its corresponding surface patch, such as... Figure 3 As shown in (b). After creating all the "Boxes", use the "Paste" command to perform a "face-to-face" snapping operation between adjacent "Boxes", as follows. Figure 3(c) This command directly mates the corresponding faces of the two selected "Boxes," ensuring precise alignment of their geometric boundaries at their contact points, thus forming a shared-edge relationship. Finally, as... Figure 3 As shown in (d), point-to-point and line-to-line snapping operations are performed to ensure a tight fit between the "Box" structure and the rectangular geometric model, thereby improving the integrity and structural stability of the overall geometric model. This operation not only improves the overall geometric consistency of the model but also effectively avoids errors caused by gaps or overlaps between different "Boxes". After completing the above steps, the number of sides for each "Box" can be set, such as... Figure 3 As shown in (e). Then, using the "Volume Mesh" command, the entire fitted "Box" is meshed using pure hexahedral meshes, ultimately resulting in a hexahedral finite element mesh, as shown. Figure 3 As shown in (f), for the columnar geometric model, an "O-Grid structure," or "butterfly grid," is adopted. The "O-Grid" command is used to select the frame faces already fitted to the "Box" and offset them inwards, thus effectively constructing an orthogonal structure, the so-called "butterfly structure." This method not only optimizes the utilization efficiency of the geometric interior space but also enhances the geometric properties of the model.

[0077] To ensure the generation of high-quality finite element meshes, this invention proposes a "layered meshing" method, such as... Figure 4 As shown in (a), this is the geometric model that has been fitted with the "Box". After the geometric model is meshed into hexahedrons, the internal mesh arrangement is as follows. Figure 4 As shown in (b), the middle mesh size is large, while the mesh sizes at both ends are smaller, resulting in an uneven overall mesh distribution. Therefore, the "Split" command is used to uniformly divide the geometric model that has been fitted to the "Box," as follows: Figure 4 As shown in (c), this operation can better constrain the outline of the geometric model and improve the arrangement of the internal mesh. Figure 4 (d) shows the internal node distribution of the segmented "Box". The sorting and layout of the internal mesh can be controlled by moving the nodes. These operations significantly improve the quality of the finite element mesh, as shown in the specific results. Figure 4 As shown in (e), a more reasonable and uniform mesh distribution is observed, laying a good foundation for subsequent finite element analysis.

[0078] (3) Methods for adjusting the physiological curvature of the spine of Chinese male car occupants at the 95th percentile.

[0079] When volunteers undergo CT scans, they are in a supine position, and their physiological curvature is as follows: Figure 5As shown in (a), it needs to be corrected according to the normal physiological structure of the spine to conform to the physiological curvature of the spine in a sitting position. The normal physiological curvature image of the adult spine was imported into Catia software. Using the point-plotting method, three points were marked on the upper, middle, and lower regions of the anterior surface of each of the 7 cervical vertebrae (C1-C7), 12 thoracic vertebrae (T1-T12), and 5 lumbar vertebrae (L1-L5), and one point was marked on the upper surface of the anterior end of the sacrum. The 73 points were connected using a spline curve to obtain the standard physiological curvature curve of the adult spine, as shown below. Figure 5 As shown in (b). Importing it into ANSA software, using the sacrum as a reference, the distal sacral point is aligned with the sacrum. The curve is then scaled to fit the size of the model spine. Each vertebra is individually translated and rotated to align with a point on the curve, ultimately obtaining the physiological curvature of the spine of a biomimetic model of physical impairment in the 95th percentile of Chinese males, as shown. Figure 5 As shown in (c).

[0080] For the intervertebral disc structure between vertebral bodies, the "Elements" command in the "Mesh" module is used to select the corresponding mesh surfaces between the upper vertebral body (i.e., the lower surface of the upper vertebral body) and the lower vertebral body (i.e., the upper surface of the lower vertebral body) to generate a hexahedral mesh. Then, the "Solid Builder" command is used to generate a volume mesh sequentially along the mesh edge of the vertebral structure, ensuring that the volume mesh of each intervertebral disc can be seamlessly integrated with the vertebral structures at both ends to construct the annulus fibrosus. After completing the initial volume mesh generation, the "Split Cases" command is used to divide the overall mesh along the outer edge to make the mesh evenly distributed. Finally, the "MOVE GRIDS" command is used to select the hexahedral mesh nodes on the outer periphery of the intervertebral disc and offset them by a certain distance within a radius range to simulate the arc-shaped structure of the outer surface of the annulus fibrosus.

[0081] (4) Method for determining and adjusting the sitting posture of a digital evaluation model for automobiles with physical characteristics of the 95th percentile male in China.

[0082] Referring to the comfortable trunk angle range (i.e., the normal sitting angle range of an occupant) under the standard sitting posture of the 95th percentile male, the upper arm angle is 0°–30°, the forearm angle is 120°–160°, the backrest angle is 20°–30°, the angle between the trunk and thigh is 95°–115°, the knee angle is 100°–145°, and the ankle angle is 87°–110°. The injury biomimetic model is adjusted to the occupant posture using the pelvic structure as a reference. Figure 8 As shown, adjust the corresponding upper arm angle, forearm angle, backrest angle, torso angle, knee angle, and ankle angle by rotating around the center of rotation of the shoulder joint, elbow joint, wrist joint, hip joint, knee joint, and ankle joint.

[0083] (5) Muscle optimization and adjustment method for digital evaluation model of automobile with physical characteristics of the 95th percentile of Chinese males.

[0084] When the human upper and lower limbs are flexed and stretched, the corresponding muscles will also be compressed and stretched. According to the principles of skeletal muscle movement anatomy, the muscles in the aforementioned bionic model of injury need to be optimized to make them more in line with the muscle morphology of the human body in a sitting position.

[0085] For areas with small range of motion, such as the shoulder, elbow, wrist, and ankle joints, simple deformation of the muscles in these areas is performed, i.e., stretching and compressing using the "MORPH" modifier, adjusting the penetration between areas to conform to anatomical structural features. For areas with large range of motion, such as the hip and knee joints, the range of muscle deformation is large, and simple stretching and compression cannot guarantee mesh quality and may even cause model distortion. For example... Figure 9 As shown in (a), this is the uncorrected finite element model of the muscle; a "Box" is constructed from it using "MORPH", as follows. Figure 9 As shown in (b), in order to achieve the best correction effect, “Boxes” can be created in segments;

[0086] By moving the node above the "Box", the muscle is stretched and compressed. The corrected muscle is as follows: Figure 9 As shown in (c); 2D shell elements are generated on the overall surface of the deformed muscle using "Vol.Shell", and then re-imported into Geomagic to generate a new muscle geometry model, as shown. Figure 9 As shown in (d); the new geometric model is re-divided into surface patches, as follows: Figure 9 As shown in (e); finally, following the method in (2) above, the corrected finite element model is obtained, as shown in (e). Figure 9 As shown in (f).

[0087] (6) Connection of a digital evaluation model for automobiles with the physical characteristics of the 95th percentile male in China.

[0088] The head, neck, chest, abdomen, pelvis, and limbs of the biomimetic model of injury are connected using ligaments, tendons, fat, and skin. Ligaments are simulated by constructing "Faces" between bones; "Faces" are first constructed between bones and muscles, and then pentahedrons are generated on the surfaces of hexahedrons and adjacent shell elements using the "Elements" command. These 2D shell elements and pentahedrons simulate tendon structures. The fat structure is constructed using the outer skin geometry model. To ensure uniform mesh distribution in the fat structure, the skin geometry model is first segmented, and then a fascia is constructed by covering the overall model structure with a surface membrane (2D shell elements). Finally, the fascia is projected onto the skin geometry using the "Extrude" command; finally, a 2D shell element structure is generated on the constructed fat surface using the "Vol.Shell" command to simulate the skin structure. Figure 10As shown, this is the digital evaluation model for automobiles in this invention, which features the physical characteristics of a male at the 95th percentile in China.

[0089] The digital evaluation model of vehicle occupant posture with the physical characteristics of a male in the 95th percentile of China in this invention has a more detailed muscle structure in the upper limbs, lower limbs, chest and abdomen, and pelvis. In contrast, the existing finite element dummy model does not have a detailed muscle structure and uses an equivalent muscle pattern for the upper and lower limbs without subdividing the muscle structure.

[0090] The advantage of using hexahedral meshes in this invention is that there are more contact surfaces between hexahedral elements, thus obtaining more interpolation information and achieving faster convergence speed, which has a significant advantage in numerical simulation.

[0091] like Figure 11 As shown, the digital vehicle assessment model with the physical characteristics of the 95th percentile male in China, as disclosed in this invention, was placed on a seat to simulate a frontal collision test, and the injury mechanism of the 95th percentile male vehicle occupant in China was studied; as Figure 12 As shown, the output shows the acceleration of the model's head, first thoracic vertebra (T1), eighth thoracic vertebra (T8), and pelvic region in the experiment, which can be used to evaluate human injury in a frontal collision with a car.

[0092] The digital vehicle evaluation model, which exhibits the physical characteristics of a 95th percentile male in China, is moved onto the seat using "translation" and "rotation" tools, ensuring contact between the model and the seat without penetration. In Primer software, a three-point seatbelt is constructed on the model, the seatbelt path is adjusted to ensure proper fit between the shoulder straps and lap belt and the model, the seatbelt pretension and retractor force are set, and material properties are assigned to the seatbelt. In ANSA software, the *CONTACT_AUTOMATIC_SINGLE_SURFACE keyword is selected to define the self-contact between the various tissue structures of the injury biomimetic model; the *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE keyword is selected to define the contact between the model and the seat belt and seat; and the *DATABASE_HISTORY_NODE(_ID) keyword is selected to define the measurement points on the head, T1 thoracic vertebra, T8 thoracic vertebra, and pelvis of the model. A gravity field is set for the digital vehicle evaluation model and seat model with the physical characteristics of a 95th percentile male in China. A velocity curve is applied to the seat model, and a frontal collision test is conducted. The corresponding kinematic and biomechanical parameters are output for the digital vehicle evaluation model with the physical characteristics of a 95th percentile male in China, and the injury status of the vehicle occupant with the physical characteristics of a 95th percentile male in China is comprehensively evaluated.

[0093] This invention provides a digital assessment model for automobiles based on the physical characteristics of the 95th percentile male in China, serving as an important tool for integrated research on active and passive safety in automobiles and the development of safety protection devices. The digital assessment model is developed and applied based on finite element software, primarily used to analyze human injury during automobile collisions; it is also known as a biomechanical model. The model conforms to the latest measurement and statistical data of the 95th percentile male height in China from the China National Institute of Standardization. The model possesses detailed anatomical structural features, and corresponding material properties are assigned to different tissue structures based on their mechanical characteristics. This invention can provide fundamental data and technical support for automobile design and safety research, road traffic accident research, medical research and medical device design, and emergency rescue implementation.

[0094] The scope of protection of this invention is not limited to the above embodiments. Any variations and advantages that can be conceived by those skilled in the art without departing from the spirit and scope of this invention are included in this invention and are protected by the appended claims.

Claims

1. A method for constructing a digital evaluation model of an occupant posture automobile with the physical characteristics of the 95th percentile of Chinese males, characterized in that, The model feature size conforms to the latest measurement of the 95th percentile male physical sign statistical data of China by China Standardization Research Institute, the model weight is 85.3 kg, the sitting height is 99.9 cm, the shoulder width is 41.5 cm, the maximum shoulder width is 49.4 cm, the chest thickness is 25.6 cm, the chest width is 31.8 cm, the unit number is 1.536 million, and the node number is 1.203 million; the model has detailed human anatomy structure features, including bones, muscles, internal organs, fat, soft tissue, ligaments, tendons and skin structure; the model is simulated by using hexahedral elements, quadrilateral shell elements, pentahedral elements and / or triangular shell elements according to different structures and parts of the human body, and the connection between the structures is realized by using the common node method; the structure in the model is endowed with corresponding material properties according to its different mechanical properties, and the contact is defined according to the structure relationship; The model uses hexahedral finite element grid to construct the heart structure including left atrium, right atrium, left ventricle, right ventricle, pulmonary artery, aorta, superior vena cava and inferior vena cava structure, constructs the sacrum structure including sacral canal, presacral foramen and posterosacral foramen structure, and constructs the hip bone structure including acetabular fossa, obturator foramen, pubic tubercle, ischial tuberosity, iliac body and iliac wing; The construction method specifically comprises: Step A: according to the latest human physical sign statistical data, the CT image data of the volunteers conforming to the physical sign of the 95th percentile male in China is obtained in multiple times, and the human body geometric model is reconstructed according to the CT image data; Step B: the human body geometric model obtained in step A is subjected to finite element grid division, and the finite element models of various structures including the heart, sacrum, hip bone and spine are constructed; the heart, sacrum and hip bone are constructed by pure hexahedral elements, and the spine is constructed by hexahedral elements and quadrilateral shell elements; Step C: the spine physiological curvature correction is performed on the spine finite element model constructed in step B, and the construction of intervertebral disc, nucleus pulposus, annulus fibrosus and ligament is performed; the nodes of the annulus fibrosus at different positions of the spine on the hexahedral grid are selected by the "Move" command to offset, so as to simulate the arc structure of the outer surface of the annulus fibrosus; Step D: the finite element models of various structures constructed in step B and the spine finite element model with adjusted physiological curvature constructed in step C are connected into the finite element model of the standing posture of the male with the 95th percentile physical sign in China by the way of muscle tendon and ligament; Step E: the standing posture finite element model obtained in step D is adjusted to the passenger posture according to the normal sitting angle range of the passenger, and the muscle grid division is inversely optimized and adjusted; Step F: the parts of the passenger posture automobile finite element model of the male with the 95th percentile physical sign in China are connected, and finally the passenger posture automobile digitized evaluation model with the physical sign of the 95th percentile male in China is obtained.

2. The construction method of claim 1, wherein, In step A, the human body is reconstructed according to the CT image data including bones, muscles, internal organs, soft tissue and skin structure; The human body geometric model is divided into rectangular geometric model, trapezoidal geometric model and columnar geometric model according to shape; And / or, The reconstructed human body geometric model comprises the following substeps: Step A1: In the Mimics software, the geometry of each tissue structure is extracted by including bone, fat, skin, internal organs, muscle structure in different gray value ranges, and a 3D model is generated; Step A2: For the generated 3D model, the "Smooth" instruction is used to define the smoothing coefficient, the "Reduce" instruction is used to define the tolerance and edge angle, and the "Wrap" instruction is used to define the gap closing distance. The surface of the geometric model is defined and processed by "Smooth", "Reduce", "Wrap", and output in *.STL file format; Step A3: Import the *.STL file obtained in step A2 into Geomagic software, and perform operations including refinement, fast smoothing, relaxation, deletion of spikes, and feature removal on the geometric model. Optimize the edge curvature of the geometric model, repair the holes of the geometric model, and optimize the geometry of adjacent geometric models using Boolean operations. Finally, the smoothed model is fitted to a NURBS surface and converted to a *.SAT format CAD model output; and / or, The gray value ranges of different tissue structures include the following: bone [148, 661], fat [-51, 205], skin [-718, -177], muscle [-5, 135], and internal organs [-178, 146]; and / or, The "Smooth" instruction is used to define the smoothing coefficient as 0.6, the "Reduce" instruction is used to define the tolerance as 1 mm, the edge angle is defined as 10°, and the "Wrap" instruction is used to define the gap closing distance as 5 mm.

3. The construction method of claim 1, wherein, In step B, the heart structure including the left atrium, right atrium, left ventricle, right ventricle, pulmonary artery, aorta, superior vena cava, and inferior vena cava structure is constructed using hexahedral finite element mesh, the sacrum structure including the sacral canal, presacral foramen, and post-sacral foramen structure is constructed, the hip bone structure including the acetabular fossa, obturator foramen, pubic tubercle, ischial tuberosity, iliac body, and iliac wing is constructed, and the spine structure including the pyramidal bone, intervertebral disc, and spinal cord is constructed. The ligament structure on the spine is constructed using tetrahedral shell elements; and / or, The finite element mesh division method includes the following sub-steps: Step B1: Import the geometric model processed in step A into ANSA software in *.SAT format; Step B2: For a rectangular geometric model, use the "Hexahedral-box" method to create a "Box" for the entire geometric model in the "HEXA BLOCK" module using the "Boxes" instruction, segment the "Box" according to the surface patch distribution position, move the nodes on the "Box" to the intersection points of the contour lines on the surface patches, and then perform point-to-point and line-to-line fitting; and / or, For a trapezoidal geometric model, use the "Hexahedral-box-box" method to create "Boxes" for the geometric model according to the surface patches, and use the "Paste" command to "face-to-face" fit the corresponding faces of the adjacent two "Boxes" to make the "Boxes" share edges; and / or, For the cylindrical geometry model, the "O-Grid structure" is adopted, and the frame surface of the "Box" is selected inwardly offset by the "O-Grid" command to construct the orthogonal butterfly structure; Step B3: The "Layered Mesh" method is adopted, and the key areas of the "Box" are uniformly segmented and the internal grid distribution is constrained; Step B4: According to the grid size requirement, the grid number of the edge of the "Box" is set by the "Number" command; Step B5: The "Volume Mesh" instruction is used to divide the entire "Box" into pure hexahedral grids, and the hexahedral grid is smoothed to complete the hexahedral grid division of the geometry model; And / or, The grid size requirement is that the maximum unit size is not more than 12 mm, and the minimum unit size is not more than 1 mm.

4. The construction method of claim 1, wherein, In step C, for the annulus fibrosus at different positions of the spine, the average offset distance of the annulus fibrosus of the cervical spine part is 0.6-0.8 mm; the average offset distance of the annulus fibrosus of the thoracic spine part is 0.8-1.0 mm; and the average offset distance of the annulus fibrosus of the lumbar spine part is 1.0-1.2 mm; And / or, The correction and construction of the physiological curvature of the spine include the following sub-steps: Step C1: The point drawing method is used to draw points on the upper, middle and lower three regions of the front end surface of the 24 vertebrae of the normal spine and the upper surface of the front end of the sacrum along the median sagittal plane of the human body, and a spline curve is used to connect the 73 selected points to obtain the normal spine physiological curvature curve; Step C2: The obtained normal spine physiological curvature curve is imported into the ANSA software and scaled to make the spine physiological curvature curve the same size as the finite element model of the spine; Step C3: Take the sacrum as the reference, and make the sacrum point at the end of the normal spine physiological curvature curve fit with the sacrum, and then translate and rotate each vertebra separately to make it fit with the point on the curve, and finally obtain the physiological curvature of the 95th percentile male spine of the Chinese standard; Step C4: Through the "Elements" instruction under the "MESH" module, the construction of the intervertebral disc between each adjacent upper and lower vertebrae is completed; using the "Solid Builder" command, the lower surface of the upper vertebra and the upper surface of the lower vertebra are used as boundaries, and the annulus fibrosus is constructed around the edge of the constructed intervertebral disc, and then the nodes on the finite element grid of the annulus fibrosus are moved by the "Move" command to simulate the arc structure of the outer surface of the annulus fibrosus; Step C5: The quadrilateral grid is constructed to simulate the structures between the vertebrae including the articular process joint capsule, articular cartilage, interspinous ligament, supraspinous ligament, transverse ligament, yellow ligament, anterior longitudinal ligament and posterior longitudinal ligament, and the 95th percentile male spine finite element model in accordance with the normal physiological curvature is obtained.

5. The construction method of claim 1 wherein, The construction of the standing posture finite element model of the 95th percentile male of the Chinese standard in step D includes the following sub-steps: Step D1: Take the head finite element model as the reference, and connect the spine finite element model corrected and constructed in step C with the head finite element model; Step D2: the rib finite element model is adjusted and connected according to human anatomy, and the connection part of muscle and bone is simulated by 2D shell element and pentahedron; Step D3: the upper and lower limb finite element model is symmetrical according to the median sagittal plane of human body, and is connected with the corresponding bone through ligament and tendon; Step D4: the skin geometry model after smoothing treatment is imported into ANSA software, and the fat is constructed through "projection", and finally the standing finite element model of the 95th percentile male of Chinese characteristics is obtained.

6. The construction method of claim 1 wherein, The adjustment of the sitting posture of the 95th percentile male passenger in step E includes the following sub-steps: Step E1: taking the pelvic structure as the reference, the standing finite element model of the 95th percentile male is adjusted to the passenger posture; Step E2: according to the normal sitting posture angle range of the passenger, the rotation centers of the shoulder joint, elbow joint, wrist joint, hip joint, knee joint and ankle joint of the 95th percentile male finite element model are adjusted, and the corresponding arm angle, forearm angle, backrest angle, torso angle, knee angle and ankle angle are adjusted; Step E3: the muscle finite element model in the sitting posture state is corrected and connected; for the muscle structures including gluteus maximus, rectus femoris, biceps femoris long head, lateral head of gastrocnemius and medial head of gastrocnemius, the reverse engineering method is used to redivide the curved sheet, and the ANSA software is imported to redivide the grid; And / or, The normal sitting posture angle range includes: arm angle 0°-30°, forearm angle 120°-160°, backrest angle 20°-30°, torso and thigh angle 95°-115°, knee angle 100°-145°, and ankle angle 87°-110°.

7. A digital evaluation model of a vehicle with the passenger posture of the 95th percentile male of Chinese characteristics constructed by the method of any one of claims 1-6.

8. Application of the construction method of any one of claims 1-6 in vehicle design and safety research, road traffic accident research, medical research and medical device design, and emergency rescue implementation.

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