A realistic simulation analysis method for racing car torsional conditions

Abstract

The present invention discloses a realistic simulation and analysis method for torsional conditions in a racing car, belonging to the field of racing car simulation technology. The method comprises: establishing a three-dimensional model of the connection between the suspension system and the vehicle body based on Ansys; simplifying the vehicle body into shell elements; simplifying all rods in the suspension system into linear elements, simplifying the mounting axes of the suspension rods into linear elements, and simplifying the mounting ears into shell elements; simplifying the tires into linear elements based on the kingpin position, and then assigning cross-sectional properties to obtain an equivalent simplified suspension system. The rotational freedom of the triangular arm is locked, the two rear wheels are fixed, and all rods in the suspension system except the anti-roll bar and their mounting axes are set to rigidity. A pair of torques are simultaneously applied to the two front wheels, and these torques are transmitted to the monocoque through the equivalent simplified suspension system, causing the monocoque to torsionally deform. The torsional stiffness of the monocoque is calculated based on the displacement of the two front wheel kingpins in the z-direction. This method simplifies calculations and closely matches actual force and deformation conditions.

Description

Technical Field

[0001] The invention relates to a practical simulation analysis method for a torsional working condition of a racing car, and belongs to the technical field of racing car simulation. Background Art

[0002] The torsional stiffness of a vehicle body is crucial for verifying the safety of its design and ensuring the proper functioning of all vehicle components under torsional conditions. During actual driving, road forces are transmitted to the vehicle body through the suspension system. For some passenger vehicle BIWs, the suspension mounting beam can be used as a simplified force point for analysis. However, for monocoques and other structures that differ from traditional BIWs, the suspension system has multiple mounting points on the vehicle body. In this case, the position and direction of the road force transmitted to the vehicle body are more complex, making it difficult to use a simple simplified point. Instead, the suspension system must be simplified as a force-transmitting system for analysis. Some passenger vehicle manufacturers have the capability to conduct torsional testing on BIWs. However, due to the high cost of monocoques and the complex design and manufacturing processes, relying solely on experimental design is time-consuming and labor-intensive. Therefore, partial simulation is needed to replace actual experiments. However, effective simulation analysis methods are currently lacking.

[0003] Currently, existing torsional stiffness simulation analysis is mostly aimed at car bodies with simple crossbeams as the suspension mounting points. Such car bodies are subjected to simple forces during driving, and it is relatively easy to establish simulation models.

[0004] In existing simulation analyses of torsional working conditions, some methods directly apply torque to the monocoque without considering the assembly of the suspension system; some methods directly apply torque to the transverse arm ears, which does not conform to the actual working conditions; and some methods retain some suspension rods but not the ears. This will cause some torque to be applied to the monocoque through the transverse arm, and at the same time, the suspension rods themselves will also be torsioned, which does not conform to the actual working process of the suspension system.

[0005] Therefore, existing torsional stiffness analyses of monocoques or parts of steel tube frames are inaccurate, and the resulting simulation results do not conform to actual working conditions, which is not conducive to guiding our design and analysis of monocoques. Taking a pushrod suspension system as an example, most of the rods are two-force rods, and the force direction is along the rod direction, without bending deformation, while some rods will also undergo torsional deformation. At the same time, when the tire is subjected to force from the ground and transmitted to the body through the suspension system, some suspension system mounting points will apply torque to the monocoque, while some mounting points will only apply tensile pressure. Therefore, the existing simplified force analysis of the suspension system is relatively complex, and many racing teams often do not take these into account when performing torsional working condition analysis. Therefore, the purpose of the present invention is to propose a correct and complete torsional working condition analysis method suitable for monocoque racing cars or similar structures using pushrod suspension systems.

[0006] A common pushrod suspension system and its assembly with a monocoque is shown below. A pushrod suspension system primarily consists of upper and lower wishbones, pushrods, triangular arms, dampers, and anti-roll bars. During driving, when the road surface is rough or a slope is encountered, one tire experiences a downward force, while the other experiences an upward force. This creates a pair of torques, which are transmitted through the suspension system to the monocoque, causing torsional deformation. Therefore, a correct simulation model is necessary to simplify calculations while accurately reflecting the actual force transmission direction and force pattern. From the perspective of design objectives, under torsional conditions, the suspension system's transverse arms and push rods are considered two-force rods, producing only tensile and compressive deformations. If the vehicle's front direction is the x-axis, the transverse arm can rotate along the z-axis and x-axis around the ear piece mounted on the monocoque. Fisheye bearings are commonly used at the connection between suspension rods and mounting shafts. They have all rotational degrees of freedom, but the degree of freedom of rotation about their own length is an additional item and has no effect on the force and transmission. The amount of rotation in the actual suspension system is subject to certain restrictions and can be ignored in the simulation axis. The degree of freedom of rotation mentioned below also ignores the degree of freedom of rotation about its own length, the y-axis.

[0007] The push rod has x- and z-degrees of freedom relative to its mounting point on the tire, and the same degrees of freedom relative to the yoke support. The load conditions in the upper suspension section are complex. The yoke can rotate about its mounting axis, and the rods connecting the yoke to the damping springs and anti-roll bar can also rotate about two axes around their mounting bolts on the yoke. When the tire is subjected to external forces and generates torque on the vehicle body, this torque is primarily transmitted to the monocoque by the yoke support. The damping and anti-roll bar mounting supports also transmit some torque to the monocoque, while the anti-roll bar undergoes torsional deformation, sharing some of the torque. To address these complex load conditions, the present invention proposes a simulation model to effectively simulate actual conditions. Summary of the Invention

[0008] The present invention designs and develops a simulation analysis method for racing car torsion conditions that is close to reality, can simplify calculations, and is close to the actual force transmission direction and force form, which can effectively guide design.

[0009] The technical solution provided by the present invention is:

[0010] A realistic simulation analysis method for racing car torsional conditions, including:

[0011] Based on Ansys, a 3D model of the suspension system and the vehicle body connection was established;

[0012] Simplify the car body into shell elements;

[0013] All members in the suspension system are simplified into linear elements according to the hard point positions, the mounting shafts of the suspension members are simplified into linear elements, and the mounting ears are simplified into shell elements. The tires are simplified into linear elements according to the kingpin positions. After the simplification is completed, cross-sectional properties are assigned to obtain an equivalent simplified suspension system.

[0014] Establish a remote point at the intersection of the line body and the surface except the triangular arm support, and connect the remote point to the surface through a connecting pair;

[0015] The degrees of freedom of the suspension members and their mounting axes are constrained by joint pairs. When setting the degrees of freedom of the suspension members, the connections between the push rod, anti-roll bar, damper and triangular arm use ball joints at one end and universal joints at the other end.

[0016] One end of the upper and lower cross arms is connected to the mounting shaft through a universal joint, and the other end is connected to the kingpin through an ear piece;

[0017] The rotational freedom of the triangular arm is locked, the two rear wheels are fixed, and all the rods in the suspension system except the anti-roll bar and their mounting shafts are set to rigid. A pair of torques are applied to the two front wheels simultaneously. The torques are transmitted to the monocoque through the equivalent simplified suspension system, causing the monocoque to torsion deformation.

[0018] The torsional stiffness of the monocoque is calculated using the displacement of the two front wheel kingpins in the z-direction.

[0019] Preferably, the modeling of the upper and lower cross arms on the monocoque includes:

[0020] Establish remote points at both ends of all mounting axes, and then connect them to the earpieces using fixed connections in the joint pair. Select the master-slave relationship as follows: the earpiece face is the reference, the remote point is the remote part, and the connection behavior at the joint is set to flexible. Connect the earpieces to the monocoque using surface-to-surface constraints. Constrain the upper and lower cross arms to have rotational freedom of the x-axis and z-axis relative to their mounting axes, and fix the other degrees of freedom.

[0021] Preferably, the modeling of the tire and its assembly parts includes:

[0022] Use a straight line as a simplified wheel;

[0023] Create ears at the ends of the upper and lower cross arms, and create a connecting line at the intersection of the upper and lower cross arms as the tire;

[0024] Connect the tire and push rod mounting points to the established ear pieces through remote points, and give the push rod rotational freedom in all directions relative to the mounting axis and fixed translational freedom.

[0025] Preferably, the modeling of the triangular arm support includes:

[0026] The triangular arm support is simplified into a linear body and connected to the monocoque element through a remote point;

[0027] Set a remote point on the line and connect the jib to the remote point to complete the connection between the jib and its support;

[0028] Among them, the remote point is the reference and the jib support is the remote component;

[0029] The remote point on the triangular arm support is set as the reference, the triangular arm surface is set as the remote component, the remote point on the damping and push rod connection support on the triangular arm is set as the remote component, and the triangular arm surface is set as the reference;

[0030] The connections between the anti-roll bar, push rod, damper and triangular arm are all set to have only all rotational degrees of freedom at one end relative to the connecting axis and restrict all translational degrees of freedom, and the other end has only rotational degrees of freedom in the x and z directions relative to the connecting axis; the anti-roll bar and its mounting support are connected through a remote point.

[0031] Preferably, the two front wheels each apply a force of 1000N, one in an upward direction and the other in a downward direction.

[0032] Preferably, the calculation formula of the monocoque torsional stiffness is:

[0033] ;

[0034] Where, is the applied force, is the distance between the two kingpins, and are the absolute values ​​of displacement of the two front kingpins respectively.

[0035] The beneficial effects of the present invention are:

[0036] In the present invention, line elements and shell elements are used instead of solid elements, which facilitates modeling and can reduce the amount of calculation during simulation. At the same time, constraints are imposed more accurately and conveniently, reducing the workload while being able to simulate real working conditions.

[0037] The present invention provides a realistic simulation and analysis method for torsional conditions in race cars, filling the gap in the lack of comprehensive and accurate simulation and analysis methods for torsional conditions in monocoque race cars. By demonstrating the deformations of the monocoque and suspension system under relatively realistic torsional conditions, it simplifies calculations while accurately reflecting actual force transmission directions and stress patterns, providing valuable guidance for race car design.

[0038] In the present invention, by adopting a universal joint at one end and a ball joint at the other end, it is possible to avoid over-constraint caused by repeated constraints on some rotational degrees of freedom while simplifying the actual limit constraints, and the connection behavior at the connection point is selected to be flexible, which can be closer to the actual behavior and avoid over-constraint.

[0039] By customizing the local coordinate system of the joint, the rotational degrees of freedom can be accurately constrained to make it fit the actual situation.

[0040] The deformation vector probe is used to check whether the deformation form is consistent with the actual situation. The free modal analysis is used to eliminate the problems of over-constraint and under-constraint of the model. The grid independence analysis is used to improve the credibility of the results. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a deformation cloud diagram of a racing car model that is close to reality when the suspension rod member of the present invention is set to be rigid.

[0042] Figure 2 This is a simplified CATIA model of the cross arm and its mounting ears described in the present invention.

[0043] Figure 3 This is the ANSYS model of the cross arm and its mounting shaft described in the present invention.

[0044] FIG4 (a) is a schematic diagram of the connection between the cross arm mounting shaft and the cross arm ear piece according to the present invention.

[0045] Figure 4(b) is a partial view of the connection in Figure 4(a) and a diagram of the specific operation settings.

[0046] FIG5 (a) is a schematic diagram of the assembly of the transverse arm ear piece and the monocoque according to the present invention.

[0047] Figure 5(b) is a partial view and specific operation setting diagram corresponding to Figure 5(a).

[0048] FIG6 (a) is a schematic diagram showing the constraint of the cross arm relative to the mounting axis according to the present invention.

[0049] Figure 6(b) is a partial view and specific operation setting diagram corresponding to Figure 6(a).

[0050] Figure 7 This is a schematic diagram of the connection between the push rod and the ear piece at the end of the upper cross arm and the simplified tire assembly according to the present invention.

[0051] Figure 8 This is a simplified diagram of remote point connections at a tire according to the present invention.

[0052] FIG9 ( a ) is a schematic diagram showing the connection between the ear piece at the end of the cross arm and the cross arm according to the present invention.

[0053] Figure 9(b) is a partial view and specific operation setting diagram corresponding to Figure 9(a).

[0054] Figure 10 This is a schematic diagram of the connection and setting of the end of the cross arm described in the present invention.

[0055] Figure 11 This is a simplified schematic diagram of the triangular arm, damping spring, anti-roll bar and its support according to the present invention.

[0056] FIG12( a ) is a schematic diagram showing the connection between the damping spring ear, the anti-roll bar ear and the monocoque according to the present invention.

[0057] Figure 12(b) is the specific operation setting diagram corresponding to Figure 12(a).

[0058] Figure 13 Schematic diagram of the remote points on the triangular arm, damping spring and anti-roll bar support of the present invention.

[0059] FIG14( a ) is a schematic diagram of the triangular arm and its mounting support according to the present invention.

[0060] Figure 14(b) is the specific operation setting diagram corresponding to Figure 14(a).

[0061] Figure 15 This is a schematic diagram of the connection between the other mounting shaft and the triangular arm described in the present invention.

[0062] FIG16 ( a ) is a schematic diagram showing the connection between the triangular arm support and the monomer shell according to the present invention.

[0063] Figure 16(b) is a partial view and specific operation setting diagram corresponding to Figure 16(a).

[0064] FIG17( a ) is a schematic diagram of the connection between the push rod and the triangular arm according to the present invention.

[0065] Figure 17(b) is a partial view and specific operation setting diagram corresponding to Figure 17(a).

[0066] FIG18 (a) is a schematic diagram of the connection between the push rod and the outer ear piece of the cross arm according to the present invention.

[0067] Figure 18(b) is a partial view and specific operation setting diagram corresponding to Figure 18(a).

[0068] FIG19( a ) is a schematic diagram of a coordinate axis selection interface for a customized reference coordinate system according to the present invention.

[0069] Figure 19(b) shows the selection position of the corresponding operation in Figure 19(a) in the settings.

[0070] FIG20( a ) is a schematic diagram showing the connection between the damper, anti-roll bar and triangular arm according to the present invention.

[0071] Figure 20(b) is the specific operation setting diagram corresponding to Figure 20(a).

[0072] Figure 21 This is a schematic diagram of the simplified CATIA model described in the present invention.

[0073] Figure 22 This is a schematic diagram of the fixed rear kingpin according to the present invention.

[0074] Figure 23 This is a schematic diagram of applying torque to the front kingpin according to the present invention.

[0075] Figure 24 This is a schematic diagram of the total load setting according to the present invention.

[0076] Figure 25 Schematic diagram of the anti-roll bar deformation direction vector probe according to the present invention.

[0077] Figure 26 This is the deformation cloud map with a global grid size of 15 mm.

[0078] Figure 27 This is the deformation cloud map with a global grid size of 10 mm.

[0079] Figure 28 This is the deformation cloud map with a global grid size of 5 mm.

[0080] Figure 29 This is a schematic diagram of the free modal vibration analysis described in the present invention.

[0081] Figure 30 Schematic diagram of the structure of a common push rod suspension system described in the present invention.

[0082] Figure 31 Schematic diagram of the assembly relationship between a common push rod suspension system and a monocoque according to the present invention.

[0083] Figure 32 This is an enlarged cloud diagram of the deformation results of the racing car model after torsion when the suspension rod member of the present invention is set to elastic. DETAILED DESCRIPTION

[0084] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0085] Figure 1-32 As shown, the present invention provides a simulation analysis method for torsional working conditions of a racing car that is close to reality. Based on Ansys simulation software, in the Windows 11 operating environment, using the ANSYS 2024r1 version, a three-dimensional model of the connection between the suspension system and the vehicle body is established. The specific operation settings are shown in the figure.

[0086] The vehicle body is simplified into shell elements, all rods in the suspension system are simplified into linear elements according to the hard point positions, the mounting shafts of the suspension rods are simplified into linear elements, and the mounting ears are simplified into shell elements. The tires are simplified into linear elements according to the kingpin positions, and after the simplification is completed, cross-sectional properties are assigned to obtain an equivalent simplified suspension system.

[0087] Establish a remote point at the intersection of the line body and the surface except the triangular arm support, and connect the remote point to the surface through a connecting pair;

[0088] The degrees of freedom of the suspension members and their mounting axes are constrained by joint pairs. When setting the degrees of freedom of the suspension members, the connections between the push rod, anti-roll bar, damper and triangular arm use ball joints at one end and universal joints at the other end.

[0089] One end of the upper and lower cross arms is connected to the mounting shaft through a universal joint, and the other end is connected to the kingpin through an ear piece;

[0090] The rotational freedom of the triangle arm is locked, the two rear wheels are fixed, all the rods in the suspension system except the anti-roll bar and their mounting shafts are set to rigid, and a pair of torques are applied to the two front wheels at the same time. The torques are transmitted to the monocoque through the equivalent simplified suspension system, causing the monocoque torsional deformation.

[0091] The torsional stiffness of the monocoque is calculated using the displacement of the two front wheel kingpins in the z-direction.

[0092] After simplifying the three-dimensional entity into shell elements and line elements, cross-sectional properties are assigned. In Ansys, the line is fixedly connected to the surface. A remote point is first established at the intersection of the line and the surface, and then the remote point is connected to the surface through a connection pair. In the present invention, as a preferred embodiment, the bolt connection in the model is simplified in this way.

[0093] The universal joint fixes the translational degrees of freedom in the x, y, and z directions and the rotational degrees of freedom about the y axis, releasing the rotational degrees of freedom in the x and z directions. The ball joint fixes the translational degrees of freedom in the x, y, and z directions, releasing all degrees of freedom. This avoids duplicate rotational degrees of freedom constraints at both ends, which can lead to overconstrained models.

[0094] In the present invention, the rear overhang is simplified in the same manner as the front overhang, and the specific simplification process of the front overhang is taken as an example.

[0095] like Figure 2 -6, the upper and lower cross arms of the suspension system and their mounting parts on the monocoque, the simplified structure includes:

[0096] Establish remote points at both ends of all mounting axes, and then connect them to the earpieces using fixed connections in the joint pair. Select the master-slave relationship as follows: the earpiece face is the reference, the remote point is the remote part, and the connection behavior at the joint is set to flexible. Connect the earpieces to the monocoque using surface-to-surface constraints. Constrain the upper and lower cross arms to have rotational freedom of the x-axis and z-axis relative to their mounting axes, and fix the other degrees of freedom.

[0097] Among them, when setting up, the name of "Universal Joint" in the software is "Universal".

[0098] like Figure 7-10 As shown, the simplification of the tire and its assembly parts includes: using a straight line as the simplified tire, and since the push rod has all rotational degrees of freedom relative to the mounting point on the cross arm, an ear piece is established at the end of the cross arm line, and a connecting line is established at the intersection of the upper and lower cross arms (the original hard point position) as the tire; the tire and the push rod mounting point are connected to the corresponding ear piece through a remote point, and the push rod is given rotational degrees of freedom in all directions relative to the mounting axis, and the translational degrees of freedom are fixed.

[0099] Shell elements are established according to the actual shape of the triangular arm support, and line elements are established according to the actual positions of the installation axes of the push rod, damper, and anti-roll bar on the triangular arm. The damper, anti-roll bar and their mounting ears on the monocoque are simplified, and the rotational freedom of the connecting line body about the installation axis is constrained to simulate a real motion scenario.

[0100] The rotational freedom of the yoke around its mounting bracket needs to be restricted. Since a real yoke can rotate around its mounting bracket, when analyzing the monocoque's torsional stiffness, the formula for calculating the monocoque's torsional stiffness must include the kingpin. The z-direction displacement generated by a z-direction force is then calculated. Therefore, to study the motion of the suspension system under torsional conditions, the present invention preferably locks the yoke's degrees of freedom, restricting its rotational freedom around its mounting bracket. This treats the yoke as a force-transmitting system, ensuring that the kingpin's displacement is solely due to the torsion of the monocoque.

[0101] The modeling of the triangular arm support includes: simplifying the triangular arm support into a linear body, connecting it to the monocoque through a remote point, setting a remote point on the linear body, and connecting the triangular arm to the remote point to complete the connection between the triangular arm and the support. In the present invention, as a preference, the remote point on the triangular arm support is set as a reference, and the triangular arm surface is set as a remote component. The damper, push rod, and remote point on the connecting support on the triangular arm are set as remote components, and the triangular arm surface is set as a reference; the connection between the anti-roll bar, push rod, damper, and triangular arm is uniformly set as follows: one end of the connecting rod has only all rotational degrees of freedom relative to the connecting axis and restricts all translational degrees of freedom, and the other end has only rotational degrees of freedom in the x and z directions relative to the connecting axis, and the anti-roll bar and its mounting support are connected through a remote point.

[0102] Simplifications of the connecting ears between the damping and anti-roll bars and the wedge arms include:

[0103] like Figure 11-2 As shown in FIG0 , the other end of the push rod is connected to the triangular arm through a universal joint, the anti-roll bar connecting rod and the damper are connected to the triangular arm through a universal joint, the other end is connected to its mounting bracket on the monocoque through a ball joint, and both ends of the anti-roll bar are connected to the anti-roll bar bracket on the monocoque through remote points.

[0104] All joints are designed to be flexible, and the local coordinate system is defined by itself. The local coordinate system generally takes the axis direction of the rod itself as the y-axis and the axis direction of the rod installation axis itself as the z-axis to accurately simulate the actual degrees of freedom.

[0105] After completing the above simplified settings, the model is assigned actual material strength properties to simulate actual torsional conditions.

[0106] like Figure 21-29 As shown in the figure, it is a simplified model diagram and the deformation cloud diagram of the torsion working condition of this model. The constraint method is: apply a force of 1000N to each of the two front tires, one in an upward direction and the other in a downward direction, while fixing the two rear tires. Figure 32 Zooming in on the deformation results shows that under torsional conditions, the suspension system transmits torque to the monocoque. With the exception of the anti-roll bar, the other members experience no bending or torsion, only tensile and compressive deformation, consistent with actual operating conditions. Free modal vibration analysis also shows that the first six modes are zero, and the 0Hz mode exhibits no local component displacement, indicating neither overconstraint nor underconstraint. A mesh independence analysis shows that the results vary by less than 1.5 percent as the mesh is gradually refined.

[0107] Finally, after confirming that the simulation was correct, the suspension members were set to rigid and the solution was repeated. The calculation showed that the torsional stiffness of the monocoque was 5488 Nm / °.

[0108] The calculation formula for the torsional stiffness of the monocoque is:

[0109] ;

[0110] Where, is the applied force, is the distance between the two kingpins, and are the absolute values ​​of displacement of the two front kingpins respectively.

[0111] It can be seen that this method can transmit torque to the monocoque more accurately and realistically, and demonstrates the deformation of the monocoque and suspension system under relatively realistic torsional working conditions.

[0112] In the present invention, line elements and shell elements are used instead of solid elements, which facilitates modeling and can reduce the amount of calculation during simulation. At the same time, the application of constraints is more accurate and convenient, which can simulate real working conditions while reducing the workload, and is conducive to guiding racing car design.

[0113] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A simulation analysis method for torsional working conditions of a racing car close to reality, characterized by: include: Based on Ansys, a 3D model of the suspension system and the vehicle body connection was established; Simplify the car body into shell elements; All members in the suspension system are simplified into linear elements according to the hard point positions, the mounting shafts of the suspension members are simplified into linear elements, and the mounting ears are simplified into shell elements. The tires are simplified into linear elements according to the kingpin positions. After the simplification is completed, cross-sectional properties are assigned to obtain an equivalent simplified suspension system. Establish a remote point at the intersection of the line body and the surface except the triangular arm support, and connect the remote point to the surface through a connecting pair; The degrees of freedom of the suspension members and their mounting axes are constrained by joint pairs. When setting the degrees of freedom of the suspension members, the connections between the push rod, anti-roll bar, damper and triangular arm use ball joints at one end and universal joints at the other end. One end of the upper and lower cross arms is connected to the mounting shaft through a universal joint, and the other end is connected to the kingpin through an ear piece; The rotational freedom of the triangular arm is locked, the two rear wheels are fixed, and all the rods in the suspension system except the anti-roll bar and their mounting shafts are set to rigid. A pair of torques are applied to the two front wheels simultaneously. The torques are transmitted to the monocoque through the equivalent simplified suspension system, causing the monocoque to torsion deformation. The torsional stiffness of the monocoque is calculated using the displacement of the two front wheel kingpins in the z-direction.

2. The method for simulating and analyzing the torsional working condition of a racing car according to claim 1, characterized in that: The modeling of the upper and lower cross arms on the monocoque includes: Establish remote points at both ends of all mounting axes, and then connect them to the earpieces using fixed connections in the joint pair. Select the master-slave relationship as follows: the earpiece face is the reference, the remote point is the remote part, and the connection behavior at the joint is set to flexible. Connect the earpieces to the monocoque using surface-to-surface constraints. Constrain the upper and lower cross arms to have rotational freedom of the x-axis and z-axis relative to their mounting axes, and fix the other degrees of freedom.

3. The method for simulating and analyzing the torsional working condition of a racing car according to claim 2, characterized in that: The modeling of the tire and its assembly parts includes: Use a straight line as a simplified wheel; Create ears at the ends of the upper and lower cross arms, and create a connecting line at the intersection of the upper and lower cross arms as the tire; Connect the tire and push rod mounting points to the established ear pieces through remote points, and give the push rod rotational freedom in all directions relative to the mounting axis and fixed translational freedom.

4. The method for simulating and analyzing the torsional working condition of a racing car according to claim 3, characterized in that: The modeling of the triangular arm support includes: The triangular arm support is simplified into a linear body and connected to the monocoque element through a remote point; Set a remote point on the line and connect the jib to the remote point to complete the connection between the jib and its support; Among them, the remote point is the reference and the jib support is the remote component; The remote point on the triangular arm support is set as the reference, the triangular arm surface is set as the remote component, the remote point on the damping and push rod connection support on the triangular arm is set as the remote component, and the triangular arm surface is set as the reference; The connections between the anti-roll bar, push rod, damper and triangular arm are all set to have only all rotational degrees of freedom at one end relative to the connecting axis and restrict all translational degrees of freedom, and the other end has only rotational degrees of freedom in the x and z directions relative to the connecting axis; the anti-roll bar and its mounting support are connected through a remote point.

5. The method for simulating and analyzing the torsional working condition of a racing car according to claim 4, characterized in that: The two front wheels each apply a force of 1000N, one in an upward direction and the other in a downward direction.

6. The method for simulating and analyzing the torsional working condition of a racing car according to claim 5, characterized in that: The calculation formula of the monocoque torsional stiffness is: ； Where, is the applied force, is the distance between the two kingpins, and are the absolute values ​​of displacement of the two front kingpins respectively.

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