Bolt type selection method and device of hybrid frame assembly structure, vehicle and medium

Abstract

The invention relates to the technical field of bolt type selection, in particular to a bolt type selection method and device for a hybrid frame assembly structure, a vehicle and a medium, and the method comprises the steps that a cast aluminum solid structure and a plate shell structure are recognized in a geometric model of the hybrid frame assembly structure, and a bolt contact area on the plate shell structure is determined; the method comprises the following steps: constructing a cast aluminum solid structure, performing grid division on the cast aluminum solid structure, simulating a bolt bar by adopting a beam unit in a grid unit, establishing a calculation model of a vehicle body, a hybrid frame assembly structure and a suspension assembly, endowing the calculation model with materials, section attributes and load working conditions, extracting load data of the beam unit under each load working condition, and calculating the load data of the beam unit; and determining and selecting the type of the bolt in the bolt contact area. Therefore, the problems of complex modeling, low benchmarking result reference, poor bolt connection position load calculation precision and the like of connection bolt type selection in large brand-new structures such as a steel-aluminum hybrid frame are solved.

Description

Technical Field

[0001] This application relates to the field of bolt selection technology, and in particular to a bolt selection method, device, vehicle, and medium for a hybrid vehicle frame assembly structure. Background Technology

[0002] Bolts are widely used detachable fasteners in automobiles, and strength verification and selection of bolts are essential tasks in engineering projects.

[0003] In related technologies, the load at the bolt connection point of the frame longitudinal beam needs to take into account the flexible deformation of the frame, which increases the connection stiffness, but requires complex modeling and will affect the accuracy of the load calculation results at the bolt connection position. Summary of the Invention

[0004] This application provides a bolt selection method, device, vehicle, and medium for hybrid vehicle frame assembly structures to solve problems such as complex modeling, low reference value of benchmarking results, and poor accuracy of bolt connection position load calculation in large new structures such as steel-aluminum hybrid vehicle frames.

[0005] The first aspect of this application provides a bolt selection method for a hybrid vehicle frame assembly structure, comprising the following steps: establishing a geometric model of the hybrid vehicle frame assembly structure; extracting a reference surface of the hybrid frame from the geometric model, identifying the cast aluminum solid structure and the plate shell structure based on the reference surface, determining the bolt contact area on the plate shell structure, and setting bolts connecting the cast aluminum solid structure and the plate shell structure within the bolt contact area; meshing the reference surface and the cast aluminum solid structure, using beam elements to simulate bolt rods in the meshed units, and establishing a calculation model of the vehicle body, the hybrid vehicle frame assembly structure, and the suspension assembly assembly; assigning material and section properties and load conditions to the calculation model, and extracting the load data of the beam elements under each load condition when the vehicle model deformation is calculated to meet the target conditions, and selecting the bolt type within the bolt contact area based on the load data.

[0006] Optionally, the hybrid frame assembly structure includes a cast aluminum solid structure and a steel plate structure, with the cast aluminum solid structure bolted to both ends of the steel plate structure.

[0007] Optionally, the shell structure includes a lower shell of the frame longitudinal beam and an upper shell of the frame longitudinal beam, with a steel plate structure provided between the lower shell of the frame longitudinal beam and the upper shell of the frame longitudinal beam, and bolt contact areas provided on the surfaces of the lower shell of the frame longitudinal beam and the upper shell of the frame longitudinal beam.

[0008] Optionally, the vehicle assembly load input for the calculation model is derived from the suspension assembly.

[0009] Optionally, the load conditions include at least one of the following: vertical impact condition, extreme cornering condition, emergency braking condition, and angular torsion condition.

[0010] Optionally, the model of the bolt in the bolt contact area is selected according to the load data, comprising: identifying axial load and tangential load in the load data; calculating guaranteed load of the bolt according to the axial load and the tangential load; selecting the model of the bolt in the bolt contact area according to the guaranteed load.

[0011] The second aspect embodiment of the application provides a bolt selection device for a hybrid frame assembly structure, comprising: a establishing module configured to establish a geometric model of the hybrid frame assembly structure; a determining module configured to extract a reference surface of the hybrid frame from the geometric model, identify an aluminum casting solid structure and a plate shell structure according to the reference surface, determine a bolt contact area on the plate shell structure, and set bolts for connecting the aluminum casting solid structure and the plate shell structure in the bolt contact area; a dividing module configured to divide the reference surface and the aluminum casting solid structure into mesh units, simulate bolt rods in the mesh units, and establish a calculation model of a vehicle body, the hybrid frame assembly structure, and a suspension assembly assembly; and an assigning module configured to assign material and cross-section properties and load conditions to the calculation model, extract load data of beam elements under each load condition when the vehicle model deformation calculated by the calculation model meets a target condition, and select the model of the bolt in the bolt contact area according to the load data.

[0012] Optionally, the establishing module is further configured to: the hybrid frame assembly structure comprises the aluminum casting solid structure and a steel plate structure, and the steel plate structure is connected with the aluminum casting solid structure at both ends through the bolts.

[0013] Optionally, the determining module is further configured to: the plate shell structure comprises a lower plate shell of a frame longitudinal beam and an upper plate shell of the frame longitudinal beam, the steel plate structure is arranged between the lower plate shell of the frame longitudinal beam and the upper plate shell of the frame longitudinal beam, and the bolt contact area is arranged on surfaces of the lower plate shell of the frame longitudinal beam and the upper plate shell of the frame longitudinal beam.

[0014] Optionally, the dividing module is further configured to: the load of the whole vehicle assembly of the calculation model is input from the suspension assembly assembly.

[0015] Optionally, the assigning module is further configured to: the load conditions comprise at least one of a vertical impact condition, a limit turning condition, an emergency braking condition, and an angular torsion condition.

[0016] Optionally, the assigning module is further configured to: the model of the bolt in the bolt contact area is selected according to the load data, comprising: identifying axial load and tangential load in the load data; calculating guaranteed load of the bolt according to the axial load and the tangential load; and selecting the model of the bolt in the bolt contact area according to the guaranteed load.

[0017] A third aspect of this application provides a vehicle, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the program to implement the bolt selection method for the hybrid frame assembly structure as described in the above embodiments.

[0018] A fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the bolt selection method for a hybrid frame assembly structure as described above.

[0019] A fifth aspect of this application provides a computer program that, when executed, is used to implement the bolt selection method for a hybrid frame assembly structure as described in the above embodiments.

[0020] Therefore, this application has the following beneficial effects: This application's embodiments identify the cast aluminum solid structure and plate shell structure within the geometric model of the hybrid frame assembly, determine the bolt contact area on the plate shell structure, and mesh the cast aluminum solid structure. Beam elements are used within the mesh cells to simulate bolts. By establishing computational models of the vehicle body, hybrid frame assembly structure, and suspension assembly, and assigning material and section properties and load conditions to these models, the load data of the beam elements under each load condition is extracted. This allows for the selection of bolt types within the bolt contact area, reducing the complexity of simulating bolt flexibility deformation and improving the accuracy and efficiency of bolt connection load calculations. Therefore, this solves the problems of complex modeling for bolt selection, low reference value of benchmark results, and poor accuracy in calculating bolt connection loads in large, novel structures such as steel-aluminum hybrid frames.

[0021] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0022] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a flowchart illustrating a bolt selection method for a hybrid frame assembly structure according to an embodiment of this application; Figure 2 This is a schematic diagram of a steel-aluminum hybrid vehicle frame model provided according to an embodiment of this application; Figure 3 This is a schematic diagram of a partial bolt connection of a vehicle frame according to an embodiment of this application; Figure 4 This is a schematic diagram showing that, according to an embodiment of this application, the outer diameter of the washer is 2.5 times the diameter of the screw. Figure 5 This is a schematic diagram of a vehicle body, a steel-aluminum hybrid frame, and a suspension assembly model provided according to an embodiment of this application; Figure 6 This is a flowchart illustrating the bolt selection calculation for a steel-aluminum hybrid vehicle frame assembly according to an embodiment of this application. Figure 7 This is an example diagram of a bolt selection device for a hybrid frame assembly structure provided according to an embodiment of this application; Figure 8 This is a schematic diagram of the structure of a vehicle according to an embodiment of this application. Detailed Implementation

[0023] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0024] The bolt selection method, apparatus, vehicle, and medium of the hybrid frame assembly structure according to embodiments of this application are described below with reference to the accompanying drawings. Addressing the problems mentioned in the background art regarding the complex modeling, low reference value of benchmarking results, and poor accuracy in calculating bolt connection loads in large, novel structures such as steel-aluminum hybrid frames, this application provides a bolt selection method for hybrid frame assembly structures. In this method, the cast aluminum solid structure and plate shell structure are identified in the geometric model of the hybrid frame assembly structure. The bolt contact area on the plate shell structure is determined, and the cast aluminum solid structure is meshed. Beam elements are used to simulate bolt rods within the mesh elements. By establishing computational models of the vehicle body, hybrid frame assembly structure, and suspension assembly, and assigning material and section properties and load conditions to the computational models, the load data of the beam elements under each load condition is extracted to determine the bolt type within the bolt contact area. This reduces the complexity of simulating bolt flexibility deformation and improves the accuracy and efficiency of calculating bolt connection loads. Therefore, the problems of complex modeling, low reference value of benchmarking results, and poor accuracy in calculating bolt connection loads in large, novel structures such as steel-aluminum hybrid frames are solved.

[0025] Specifically, Figure 1 This is a flowchart illustrating a bolt selection method for a hybrid frame assembly structure provided in an embodiment of this application.

[0026] like Figure 1 As shown, the bolt selection method for this hybrid frame assembly structure includes the following steps: In step S101, a geometric model of the hybrid frame assembly structure is established.

[0027] Among them, the hybrid frame assembly structure is a frame system that integrates two or more materials, structural modules or load-bearing logics with different characteristics to form a high-efficiency frame system that meets the performance requirements of multiple scenarios.

[0028] Understandably, by creating a geometric model of the hybrid chassis assembly structure in the software, the spatial relationships of the hybrid chassis assembly structure can be clearly displayed, and the overall layout can be presented intuitively.

[0029] Specifically, the geometric models of the steel-aluminum hybrid chassis, body, and suspension are imported using Hypermesh (finite element preprocessing software). The X-axis (positive direction or direction 1) is defined as the direction from the front to the rear of the vehicle, and the Z-axis (positive direction or direction 3) is defined as the direction vertically upward. The Y-axis of the vehicle coordinate system is defined by the right-hand screw rule, and the rotation directions around the X, Y, and Z axes represent directions 4, 5, and 6, respectively. Hypermesh software supports importing CAD (Computer-Aided Design) formats such as STEP (Standard for the Exchange of Product Model Data), IGS (Initial Graphics Exchange Specification), and CATPart (CATIA Part). Multi-component layered management is implemented, with the chassis, body, and suspension imported into different components for multi-component layered management.

[0030] Furthermore, in the embodiments of this application, the hybrid frame assembly structure includes a cast aluminum solid structure and a steel plate structure, with the cast aluminum solid structure bolted to both ends of the steel plate structure.

[0031] Among them, cast aluminum solid structure is made of aluminum alloy as raw material. Molten aluminum liquid is injected into a mold through casting and cooled to form a structural component with no obvious splicing seam; steel plate structure is made of steel as raw material. Steel plates are processed into specific shapes and then connected by welding or bolts to form structural components.

[0032] Understandably, the hybrid frame assembly structure is composed of a cast aluminum solid structure and a steel plate structure. In the hybrid frame assembly structure, the two ends of the steel plate structure are connected to the cast aluminum solid structure by bolts, which can achieve a reliable connection between dissimilar materials, avoid the difficulties of welding technology, and ensure the structural stress coordination.

[0033] Specifically, steel-aluminum hybrid frames, such as Figure 2 As shown, the chassis model is divided into three parts: front, middle and rear. The front and rear sections are solid cast aluminum structures, while the middle section is a steel plate structure. The middle longitudinal beams are connected to the front and rear cast aluminum structures by bolts. This application proposes to establish a geometric model of the hybrid frame assembly structure, which can clearly show the front, middle, and rear sections of the frame in the hybrid frame assembly structure, as well as the spatial relationship between the middle longitudinal beam and the front and rear cast aluminum structures connected by bolts, thus intuitively presenting the overall layout.

[0034] In step S102, a reference surface of the hybrid frame is extracted from the geometric model. The cast aluminum solid structure and the plate shell structure are identified based on the reference surface. A bolt contact area is determined on the plate shell structure. Bolts connecting the cast aluminum solid structure and the plate shell structure are installed in the bolt contact area.

[0035] Among them, the reference surface of the hybrid frame is a three-dimensional coordinate reference system established during the design, manufacturing and assembly process to ensure the positional accuracy and spatial relationship of each component of the frame; the bolt contact area refers to the local area in the hybrid frame where the bolt contacts the connected parts.

[0036] Understandably, extracting and identifying the cast aluminum solid structure and plate shell structure in the reference surface of the hybrid frame assembly structure from the geometric model of the hybrid frame assembly structure, thereby determining the contact area of ​​the bolts connecting the cast aluminum solid structure and the plate shell structure, can ensure the connection accuracy of dissimilar materials and improve the accuracy of simulation.

[0037] Specifically, in Hypermesh software, the surface of the frame sheet metal structure is extracted. The cast aluminum solid structure and the shell structure are identified by the reference surface of the hybrid frame. The middle surface and the cast aluminum solid structure are geometrically processed. At the connection position around the bolt hole, two layers of washers with different functions are used. Two layers of washers with different functions are also needed around the bolt hole of the solid structure. There is a contact relationship between the shell and the solid. Initially, it is assumed that the nominal diameter of the connecting bolt is D. After the geometric processing around the bolt hole is completed, the outer diameter of the washer is 2.5D, and the bolt preload area is within 2.5D.

[0038] For example, in the connection between the cast aluminum suspension solid support and the steel plate longitudinal beam, the bolts are M10 10.9 grade steel bolts. The first layer of cast aluminum solid washers uses copper flat washers with a diameter of 16mm and a thickness of 1.5mm, which are placed on the bolt shank and directly contact the periphery of the bolt hole of the cast aluminum solid. The second layer of copper flat washers uses spring steel washers with a diameter of 16mm and a thickness of 1.2mm, which are placed on the outside of the copper flat washers.

[0039] Furthermore, in the embodiments of this application, the shell structure includes a lower shell of the frame longitudinal beam and an upper shell of the frame longitudinal beam, a steel plate structure is provided between the lower shell of the frame longitudinal beam and the upper shell of the frame longitudinal beam, and bolt contact areas are provided on the surfaces of the lower shell of the frame longitudinal beam and the upper shell of the frame longitudinal beam.

[0040] Among them, the lower shell of the frame longitudinal beam is a plate-like structure arranged along the longitudinal direction of the vehicle at the lower part of the frame longitudinal beam; the upper shell of the frame longitudinal beam is a plate-like structure arranged along the longitudinal direction of the vehicle at the upper part of the frame longitudinal beam; the steel plate structure is a structured material form used to manufacture frame components, which is formed by using steel plates as raw materials and through processes such as stamping, welding, and bending.

[0041] It is understandable that the plate and shell structure in the hybrid frame assembly structure includes the lower plate and shell of the frame longitudinal beams and the upper plate and shell of the frame longitudinal beams. Its surface has bolt contact area and the middle has steel plate structure. By constructing a channel-shaped load-bearing section, it can withstand multi-directional loads such as bending, torsion, tension and compression during vehicle operation. The bolt contact area realizes the reliable connection of dissimilar materials.

[0042] Specifically, such as Figure 3 As shown, in the steel-aluminum hybrid frame model, the connecting structures are plate-shell-solid-plate-shell. The upper plate of the frame longitudinal beam is located at the top of the longitudinal beam and extends along the length of the frame. It is mainly made of high-strength duplex steel or low-alloy high-strength steel. The thickness is 3-4mm for passenger cars and 4-6mm for commercial vehicles, which can bear the static load of the upper part. The lower plate of the frame longitudinal beam is located at the bottom of the longitudinal beam and is symmetrically arranged with the upper plate. The length is the same as the upper plate. The thickness is 3.5-4.5mm for passenger cars and 5-7mm for commercial vehicles, which can withstand the dynamic impact of the ground.

[0043] This application proposes to extract and identify the cast aluminum solid structure and the plate shell structure with the lower plate shell of the frame longitudinal beam and the upper plate shell of the frame longitudinal beam in the reference surface of the hybrid frame assembly structure from the geometric model of the hybrid frame assembly structure, thereby determining the contact area of ​​the bolts connecting the cast aluminum solid structure and the plate shell structure. This can ensure the connection accuracy of dissimilar materials and improve the accuracy of simulation.

[0044] In step S103, the reference surface and the cast aluminum solid structure are meshed, and beam elements are used to simulate bolt rods in the meshed cells to establish a calculation model of the body, the hybrid frame assembly structure and the suspension assembly.

[0045] Meshing is the process of discretizing a continuous solid structure into a finite number of small elements; beam elements are a simplified element type for simulating slender structures in finite element analysis. By defining cross-sectional properties such as area, moment of inertia, and torsional stiffness, they can efficiently calculate the mechanical response of slender members; bolt shanks are the core load-bearing components of bolts, including the cylindrical part below the bolt head, with threads or a smooth shaft, which plays a crucial role in connecting different structural components and transmitting loads in the automobile frame; the suspension is the force transmission mechanism that connects the frame and the wheels.

[0046] Understandably, by using beam elements to simulate bolt rods on the reference surface after meshing and the cast aluminum solid structure mesh elements, a computational model of the body, hybrid frame assembly structure and suspension assembly is established, realizing the transformation of complex geometry into a computable mechanical model, and improving computational efficiency and connection mechanical accuracy.

[0047] Specifically, Hypermesh software was used to mesh the mid-surface and solid structures after geometric processing, including sheet metal body, hybrid frame, and solid suspension. The surface structure was meshed using quadrilateral elements, while the solid structure was meshed using second-order tetrahedral elements.

[0048] like Figure 3 As shown, there is a contact relationship between the plate shell and the solid. Beam elements are used to simulate the bolt rod. The diameter of the beam element in the contact area is set to 2.5D, and the diameter of the beam element inside the cast aluminum solid structure is set to D. The actual connecting bolt is deformable. The beam element in the contact area and the beam element inside the solid are divided into at least three segments to accurately simulate the flexibility of the bolt.

[0049] like Figure 4 As shown, the Washer region, i.e. the contact region, is connected to the beam element and the surrounding plate and shell solid structure using Rbe2 (Rigid Body Element Type 2) elements.

[0050] Furthermore, in the embodiments of this application, the vehicle assembly load input of the calculation model originates from the suspension assembly.

[0051] Among them, the computational model is a virtual model that abstractly describes the real vehicle structure or system through mathematical equations and physical parameters, and is used to transform complex physical phenomena into calculable numerical models; the assembly load is a variety of mechanical inputs acting on the vehicle assembly, which can simulate the stress state of the vehicle under actual working conditions and evaluate the strength of the structure; the suspension assembly is a mechanical system composed of elastic elements, guiding mechanisms, shock absorbers and other components, which connects the frame and the wheels.

[0052] Understandably, by inputting the load data of the whole vehicle assembly from the suspension assembly into the calculation model, the authenticity and consistency of load transfer can be guaranteed, calculation errors can be reduced, the whole vehicle-level calculation logic can be simplified, and simulation efficiency can be improved.

[0053] Specifically, such as Figure 5As shown, a calculation model of the vehicle body, frame, and suspension assembly is established. The calculation model needs to consider the vehicle body, which is the carrier for receiving and transmitting suspension loads. The forces / torques transmitted by the suspension first act on specific connection points of the vehicle body, such as the suspension control arm connecting seat and the upper support of the shock absorber, and then the load is distributed by the vehicle body to other systems such as the frame, powertrain, and interior. The calculation model incorporates the vehicle body to achieve a real physical mapping. The load input of the whole vehicle assembly comes from the suspension, so the calculation model of the whole vehicle assembly needs to consider the suspension.

[0054] This application embodiment uses beam elements to simulate bolt rods on the reference surface after meshing and the cast aluminum solid structure mesh elements to establish a calculation model of the body, hybrid frame assembly structure and suspension assembly assembly. By inputting the load data of the whole vehicle assembly from the suspension assembly into the calculation model, the transformation of complex geometry into a computable mechanical model is realized, which can ensure the authenticity and consistency of load transmission and improve the calculation efficiency and connection mechanical accuracy.

[0055] In step S104, the calculation model is assigned material and section properties and load conditions. Under the condition that the deformation of the whole vehicle model meets the target conditions, the load data of the beam element under each load condition is extracted, and the bolt type in the bolt contact area is selected according to the load data.

[0056] Among them, cross-sectional properties are quantitative parameters that describe the geometric characteristics of the cross-section of a component, directly determining the component's strength, stiffness, and resistance to deformation under stress; load conditions are the stress state of a structure under real use when multiple loads act simultaneously in a specific working scenario; and load data are quantitative descriptions of various loads in load conditions.

[0057] Understandably, by assigning material and cross-sectional properties and load conditions to the calculation model, when the calculated deformation of the whole vehicle model meets the target conditions, the load data of the beam element under each load condition is extracted, the bolt type in the bolt contact area is determined, and the bearing capacity of the bolt is accurately matched with the actual force, ensuring the bolt strength safety and stiffness matching, realizing the effective and firm connection of the bolt, and accurately realizing the bolt selection.

[0058] Specifically, the material properties assigned to the calculation model include elastic modulus, Poisson's ratio, shear modulus, and density; the cross-sectional properties assigned to the calculation model include cross-sectional geometric parameters, moment of inertia, cross-sectional modulus, cross-sectional area, and shear area; and the load conditions assigned to the calculation model include vertical impact conditions, extreme turning conditions, emergency braking conditions, and angular torsion conditions.

[0059] Furthermore, in the embodiments of this application, the load conditions include at least one of vertical impact conditions, extreme cornering conditions, emergency braking conditions, and angular torsion conditions.

[0060] Among them, the vertical impact condition simulates the dynamic load scenario of the wheels colliding instantaneously with the ground when the vehicle passes over a bump, pothole or speed bump; the extreme cornering condition simulates the lateral load scenario caused by centrifugal force when the vehicle is cornering at its maximum speed; the emergency braking condition; and the angular torsion condition simulates the longitudinal load scenario caused by inertial force when the vehicle suddenly brakes at high speed.

[0061] Understandably, the load conditions assigned to the calculation model include vertical impact conditions, extreme cornering conditions, emergency braking conditions, and angular torsion conditions, which correspond to the four core force dimensions that vehicles face in actual use: vertical, lateral, longitudinal, and torsional. Inputting these load conditions can systematically verify the structural safety and long-term reliability of the entire vehicle, ensure that the multi-dimensional performance of the entire vehicle meets the standards, and match the actual usage needs of users.

[0062] Specifically, after establishing the vehicle assembly model and assigning material and section properties, the load conditions of the calculation model are set. The main load conditions for selecting frame bolts include vertical impact, extreme cornering, emergency braking, and diagonal torsion. After the boundary conditions and load conditions are set, the model is submitted for calculation.

[0063] Connecting bolts have different functions under different working conditions. For example, connecting bolts mainly bear axial loads under vertical impact conditions, connecting bolts mainly bear tangential loads under extreme turning conditions, connecting bolts mainly bear axial loads under emergency braking conditions, and connecting bolts mainly bear combined axial and tangential loads under diagonal torsion conditions.

[0064] For example, by optimizing suspension spring stiffness through vertical impact, both bump comfort and structural strength under vertical impact can be improved simultaneously; by synergistic verification of extreme cornering and angular torsion, off-road torsional resistance can be ensured while improving handling; and by superimposed calculation of emergency braking and vertical impact, front suspension overload can be avoided while controlling braking pitch angle.

[0065] Furthermore, in the embodiments of this application, selecting the bolt type within the bolt contact area based on load data includes: identifying the axial load and tangential load in the load data; calculating the guarantee load of the bolt based on the axial load and tangential load; and selecting the bolt type within the bolt contact area based on the guarantee load.

[0066] Among them, axial load is a load that acts along the axis of the component and is perpendicular to the cross-section of the component; tangential load is a load that acts parallel to the cross-section or contact surface of the component and is perpendicular to the axis of the component; the guarantee load is the maximum load value index under the action of the load that the fastener will not produce permanent deformation and can maintain the reliability of the connection.

[0067] Understandably, by identifying the axial and tangential loads in the load data, the maximum load that the bolt can stably withstand under specified conditions is calculated. This determines the bolt type for the load selection area, ensuring that the bolt's load-bearing capacity perfectly matches the actual force, thus guaranteeing the long-term reliability and safety of the bolted connection.

[0068] Specifically, check whether the deformation of the calculation model for each load condition is correct. If it is correct, extract the beam element, that is, the axial force and tangential force of the screw under each load condition. Use the bolt connection load calculated by the whole vehicle finite element assembly model as input, calculate the bolt guarantee load according to the calculation formula of the bolt selection guarantee load, and further determine the bolt grade and nominal diameter according to the mechanical design manual or national standard to complete the bolt selection of the hybrid frame structure.

[0069] For example, the connecting bolts between the vehicle body and the front suspension control arm need to transmit vertical impact conditions and extreme cornering conditions. Through whole-vehicle finite element simulation, the load data of the beam element in the bolt connection area is extracted and converted into the actual force on the bolt. Under the vertical impact condition, the vertical force transmitted by the beam element is converted into the axial tensile load borne by the bolt after lever arm conversion. Under the extreme cornering condition, the lateral force transmitted by the beam element acts directly on the bolt, and the bolt bears the tangential shear load. When the bolt bears both axial and tangential loads at the same time, the equivalent stress theory needs to be used to convert the composite load into an equivalent tensile load, and then compared with the bolt's guarantee load to ensure that the safety factor requirements are met.

[0070] The guaranteed load value of a bolt is determined by its strength grade and specifications. You can find the guaranteed tensile load of different bolt models in the Mechanical Design Handbook or the ISO 898-1 standard, and select the model that meets the guaranteed load and is suitable for the connection area space.

[0071] This application embodiment assigns material and cross-sectional properties and load conditions to the calculation model. When the calculated deformation of the whole vehicle model meets the target conditions, the load data of the beam unit under each load condition is extracted to determine the bolt type in the bolt contact area. This ensures that the bolt's load-bearing capacity is accurately matched with the actual force, guarantees the bolt's strength safety and stiffness matching, achieves effective and firm bolt connection, and accurately realizes bolt selection.

[0072] To better understand the solution of this application, the bolt selection method or execution process of the hybrid frame assembly structure of this application is described below through a specific embodiment, as follows: Figure 6 As shown: In step S601, the bolt selection calculation for the steel-aluminum hybrid frame structure begins.

[0073] In step S602, the geometric model of the steel-aluminum hybrid frame assembly is imported.

[0074] Import the steel-aluminum hybrid frame, body, and suspension geometry models using Hypermesh preprocessing software.

[0075] In step S603, two washers are applied around the bolt holes on the middle surface of the frame steel plate.

[0076] The mid-surface of the steel plate frame structure is extracted, and the mid-surface of the frame and the cast aluminum solid structure are geometrically processed. Two washers are applied around the bolt holes, and the outer diameter meets the requirements.

[0077] In step S604, the frame steel plate structure is meshed using S4 and S3 elements.

[0078] In step S605, the cast aluminum frame structure is meshed using second-order tetrahedral elements.

[0079] Quadrilateral elements and second-order tetrahedral elements are used to mesh the plate and shell structures and solid structures.

[0080] In step S606, the Beam element simulates the bolt rod (the segmented elements have different diameters), and Rbe2 simulates the contact area.

[0081] Beam elements are used to simulate the screw. The screw needs to be segmented in different areas and the screw diameter is different. Rbe2 elements are used to simulate the bolt contact area.

[0082] In step S607, a calculation model of the vehicle body, frame, and frame assembly is established.

[0083] In step S608, the material and section properties of the assembly are established and assigned, the load conditions are set, and the calculation is performed.

[0084] In step S609, check whether the deformation of the assembly model is correct.

[0085] If the assembly model deforms correctly, the axial and tangential forces of the bolt Beam elements under each load condition are extracted; if the assembly model deforms incorrectly, the model returns to the Beam element to simulate the bolt rod (the segmented elements have different diameters), Rbe2 simulates the contact area, or returns to create a calculation model of the body, frame, and chassis assembly, or returns to create and assign material and section properties to the assembly, sets the load conditions, and solves the calculation.

[0086] In step S610, the axial force and tangential force of the screw Beam unit under each load condition are extracted.

[0087] Provided that the deformation of the whole vehicle model is correct, extract the axial force and tangential force of the Beam element (connecting bolt) under various load conditions (user application scenarios).

[0088] In step S611, the bolt guarantee load is calculated based on empirical formulas.

[0089] The guaranteed load of the connecting bolts is calculated using the formula, and the bolt type is further determined.

[0090] In step S612, the bolt grade and nominal diameter are further determined based on the bolt guarantee load.

[0091] In step S613, the bolt selection calculation for the steel-aluminum hybrid frame structure is completed.

[0092] In summary, the bolt selection method for the hybrid frame assembly structure proposed in this application identifies the cast aluminum solid structure and plate shell structure in the geometric model of the hybrid frame assembly structure, determines the bolt contact area on the plate shell structure, and meshes the cast aluminum solid structure. Beam elements are used to simulate bolt rods within the mesh elements. By establishing a calculation model of the vehicle body, the hybrid frame assembly structure, and the suspension assembly assembly, and assigning material and section properties and load conditions to the calculation model, the load data of the beam elements under each load condition is extracted to determine the bolt type within the bolt contact area. This method reduces the complexity of simulating bolt flexible deformation and improves the calculation accuracy and efficiency of loads at bolt connection locations.

[0093] Next, referring to the accompanying drawings, a bolt selection device for a hybrid frame assembly structure proposed according to an embodiment of this application is described.

[0094] Figure 7 This is a block diagram of a bolt selection device for a hybrid frame assembly structure according to an embodiment of this application.

[0095] like Figure 7 As shown, the bolt selection device 700 for the hybrid frame assembly structure includes: a creation module 701, a determination module 702, a division module 703, and an assignment module 704.

[0096] The system comprises the following modules: Module 701, which establishes the geometric model of the hybrid frame assembly structure; Module 702, which extracts the reference surface of the hybrid frame from the geometric model, identifies the cast aluminum solid structure and the plate shell structure based on the reference surface, determines the bolt contact area on the plate shell structure, and sets the bolts connecting the cast aluminum solid structure and the plate shell structure within the bolt contact area; Module 703, which meshes the reference surface and the cast aluminum solid structure, uses beam elements to simulate bolt rods in the meshed units, and establishes the calculation model of the body, the hybrid frame assembly structure, and the suspension assembly assembly; and Module 704, which assigns material and section properties and load conditions to the calculation model. Under the condition that the deformation of the whole vehicle model meets the target conditions, the module extracts the load data of the beam elements under each load condition and selects the bolt type within the bolt contact area based on the load data.

[0097] Furthermore, in this embodiment, the hybrid frame assembly structure includes a cast aluminum solid structure and a steel plate structure, with the cast aluminum solid structure bolted to both ends of the steel plate structure.

[0098] Furthermore, in this embodiment, the shell structure includes a lower shell of the frame longitudinal beam and an upper shell of the frame longitudinal beam, with a steel plate structure provided between the lower shell of the frame longitudinal beam and the upper shell of the frame longitudinal beam, and bolt contact areas provided on the surfaces of the lower shell of the frame longitudinal beam and the upper shell of the frame longitudinal beam.

[0099] Furthermore, in this embodiment of the application, the vehicle assembly load input of the calculation model originates from the suspension assembly.

[0100] Furthermore, in the embodiments of this application, the load conditions include at least one of vertical impact conditions, extreme turning conditions, emergency braking conditions, and angular torsion conditions.

[0101] Furthermore, in this embodiment of the application, the assignment module 704 is further configured to: select the bolt type within the bolt contact area based on the load data, including: identifying the axial load and tangential load in the load data; calculating the guarantee load of the bolt based on the axial load and tangential load; and selecting the bolt type within the bolt contact area based on the guarantee load.

[0102] It should be noted that the explanation of the bolt selection method embodiment for the hybrid frame assembly structure described above also applies to the bolt selection device for the hybrid frame assembly structure in this embodiment, and will not be repeated here.

[0103] According to the bolt selection device for the hybrid frame assembly structure proposed in this application, the cast aluminum solid structure and plate shell structure are identified in the geometric model of the hybrid frame assembly structure. The bolt contact area on the plate shell structure is determined, and the cast aluminum solid structure is meshed. Beam elements are used to simulate bolt rods in the mesh elements. By establishing a calculation model of the body, the hybrid frame assembly structure and the suspension assembly, the calculation model is given material and section properties and load conditions. The load data of the beam elements under each load condition is extracted to determine the bolt type in the bolt contact area. This can reduce the complexity of simulating the flexible deformation of the bolt and improve the calculation accuracy and efficiency of the load at the bolt connection position.

[0104] Figure 8 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application. The vehicle 800 may include: The memory 801, the processor 802, and the computer program stored on the memory 801 and capable of running on the processor 802.

[0105] When the processor 802 executes the program, it implements the bolt selection method for the hybrid frame assembly structure provided in the above embodiments.

[0106] Furthermore, vehicle 800 also includes: Communication interface 803 is used for communication between memory 801 and processor 802.

[0107] The memory 801 is used to store computer programs that can run on the processor 802.

[0108] The memory 801 may include high-speed RAM (Random Access Memory) memory, and may also include non-volatile memory, such as at least one disk storage.

[0109] If the memory 801, processor 802, and communication interface 803 are implemented independently, then the communication interface 803, memory 801, and processor 802 can be interconnected via a bus to complete communication between them. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 8 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0110] Optionally, in a specific implementation, if the memory 801, processor 802, and communication interface 803 are integrated on a single chip, then the memory 801, processor 802, and communication interface 803 can communicate with each other through an internal interface.

[0111] The processor 802 may be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of this application.

[0112] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the bolt selection method for the hybrid frame assembly structure described above.

[0113] This application also provides a computer program product, including a computer program or instructions, characterized in that, when the computer program or instructions are executed, they implement the bolt selection method for the above-mentioned hybrid frame assembly structure.

[0114] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0115] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0116] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0117] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any of the following techniques known in the art, or a combination thereof: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (FPGAs), field-programmable gate arrays (FPGAs), etc.

[0118] Those skilled in the art will understand that all or part of the steps of the methods implementing the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0119] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A bolt selection method for a hybrid frame assembly structure, characterized in that, Includes the following steps: Establish a geometric model of the hybrid chassis assembly structure; A reference surface for the hybrid frame is extracted from the geometric model. Based on the reference surface, the cast aluminum solid structure and the plate shell structure are identified. A bolt contact area is determined on the plate shell structure. Bolts connecting the cast aluminum solid structure and the plate shell structure are installed in the bolt contact area. Mesh the reference surface and the cast aluminum solid structure, and use beam elements to simulate bolt rods in the meshed cells to establish a calculation model of the vehicle body, the hybrid frame assembly structure and the suspension assembly assembly. Assign material and section properties and load conditions to the calculation model. When the vehicle model deformation is calculated to meet the target conditions, extract the load data of the beam element under each load condition, and select the bolt type in the bolt contact area based on the load data.

2. The bolt selection method for the hybrid frame assembly structure according to claim 1, characterized in that, The hybrid frame assembly structure includes a cast aluminum solid structure and a steel plate structure, with the cast aluminum solid structure bolted to both ends of the steel plate structure.

3. The bolt selection method for the hybrid frame assembly structure according to claim 2, characterized in that, The shell structure includes a lower shell of the frame longitudinal beam and an upper shell of the frame longitudinal beam. The steel plate structure is provided between the lower shell of the frame longitudinal beam and the upper shell of the frame longitudinal beam. The bolt contact area is provided on the surface of the lower shell of the frame longitudinal beam and the upper shell of the frame longitudinal beam.

4. The bolt selection method for the hybrid frame assembly structure according to claim 1, characterized in that, The load input of the vehicle assembly in the calculation model comes from the suspension assembly.

5. The bolt selection method for the hybrid frame assembly structure according to claim 1, characterized in that, The load conditions include at least one of the following: vertical impact condition, extreme turning condition, emergency braking condition, and angular torsion condition.

6. The bolt selection method for the hybrid frame assembly structure according to claim 1, characterized in that, The step of selecting the bolt type within the bolt contact area based on the load data includes: Identify the axial and tangential loads in the load data; The guarantee load of the bolt is calculated based on the axial load and the tangential load. The bolt type within the bolt contact area is selected based on the guaranteed load.

7. A bolt selection device for a hybrid vehicle frame assembly structure, characterized in that, include: A module is created to build the geometric model of the hybrid chassis assembly structure; The determination module is used to extract a reference surface of the hybrid frame from the geometric model, identify the cast aluminum solid structure and the plate shell structure based on the reference surface, determine a bolt contact area on the plate shell structure, and set bolts connecting the cast aluminum solid structure and the plate shell structure within the bolt contact area; The meshing module is used to mesh the reference surface and the cast aluminum solid structure. In the meshed cells, beam elements are used to simulate bolts and to establish a calculation model of the vehicle body, the hybrid frame assembly structure and the suspension assembly assembly. The assignment module is used to assign material and cross-sectional properties and load conditions to the calculation model. When the calculation model calculates the deformation of the whole vehicle model to meet the target conditions, it extracts the load data of the beam element under each load condition and selects the bolt type in the bolt contact area according to the load data.

8. A vehicle, characterized in that, The hybrid frame assembly structure of the vehicle is bolted, and the bolts are selected using the bolt selection method for the hybrid frame assembly structure as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed, they implement the bolt selection method for the hybrid frame assembly structure according to any one of claims 1-6.

10. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed, they implement the bolt selection method for the hybrid frame assembly structure according to any one of claims 1-6.

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