New energy automobile wheel and bolt triaxial endurance fatigue test system and test method thereof

Abstract

A new energy automobile wheel and bolt triaxial endurance fatigue test system and a test method thereof relate to the field of automobile hub processing, and comprise a dynamic test wheel, and strain gauges are pasted at the positions of a spoke, a rim, a rim, a bolt hole and a center hole of the dynamic test wheel; the wheel bolt axial force strain gauge is pre-buried in a shaft core drill hole of the finished wheel bolt; the wheel six-component sensor is assembled on the processing rim; the three-axis endurance fatigue test system is provided with a broadband response road simulation test bench used for installing a suspension clamp of a wheel-tire assembly. And a new generation of wheel and bolt triaxial endurance fatigue test technical scheme with ultrahigh strength, excellent fatigue resistance and reliable anti-loosening capability is developed.

Description

Technical Field

[0001] This invention relates to the field of automotive wheel hub processing technology, specifically to a triaxial durability fatigue testing system and method for new energy vehicle wheels and bolts. Background Technology

[0002] New energy vehicle wheels and connecting bolts face severe load challenges. In recent years, the global pace of technological iteration and market penetration in new energy vehicles has accelerated, placing unprecedentedly stringent requirements on the service performance of core load-bearing components—wheels and wheel connecting bolts. Due to their unique structure, new energy vehicles generally exhibit load characteristics significantly different from traditional gasoline-powered vehicles:

[0003] 1. Significant increase in static load: To ensure driving range, vehicles need to be equipped with high-energy-density power battery packs, and some hybrid models also need to accommodate internal combustion engine systems, resulting in a significant increase in the overall vehicle curb weight and a sharp increase in the static support load on the wheels and connecting bolts.

[0004] 2. Increased longitudinal impact load during start-up / acceleration: The drive motor has the characteristic of instantaneous burst of large torque. Especially during vehicle start-up and rapid acceleration, the longitudinal driving force applied to the wheels and their connection interfaces is far greater than that of traditional combustion engines, generating huge instantaneous impact loads.

[0005] 3. Increased braking inertial load: Due to the vehicle's massive weight, a stronger counter-torque is required during braking to overcome the enormous inertia. Even with the assistance of a kinetic energy recovery system, the mechanical braking system and its associated wheels and bolts still bear extremely high alternating shear and tensile loads.

[0006] New energy vehicles operate under severe combined conditions of continuous high static load, high starting / acceleration impact, and high braking inertia for extended periods, posing extremely serious challenges to the fatigue strength limit, anti-loosening performance, wear resistance, and overall structural reliability of the wheel structure (especially the wheel hub bearing unit) and key fasteners—wheel connecting bolts. Summary of the Invention

[0007] In view of this, the present invention aims to propose a triaxial durability fatigue testing system and method for new energy vehicle wheels and bolts, which is a new generation of triaxial durability fatigue testing technology for wheels and bolts with ultra-high strength, excellent fatigue resistance and reliable anti-loosening ability.

[0008] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0009] A triaxial durability fatigue testing system for new energy vehicle wheels and bolts includes a dynamic test wheel with strain gauges attached to its spokes, rim, flange, bolt holes, and center hole; a wheel bolt axial force strain gauge pre-embedded in the core drilled hole of the finished wheel bolt; a wheel six-component force sensor assembled on the machined rim; and a broadband response road simulation test bench equipped with a suspension fixture for mounting the wheel-tire assembly. The suspension fixture includes a lower control arm fixture, an upper control arm fixture, a support beam, and a mounting plate. The test bench also includes a drive shaft and braking assembly for applying longitudinal loads to the wheel. The dynamic test wheel, wheel bolt axial force strain gauge, and wheel six-component force sensor can be combined and installed at different wheel positions on the test vehicle. The test bench is used to simultaneously apply radial, lateral, and longitudinal triaxial loads to the wheel-tire assembly mounted on it based on a block load spectrum developed from real vehicle road test signals.

[0010] In some embodiments, the wheel bolt axial strain gauge is a needle-shaped axial strain gauge, which is fixed in the core hole of the finished wheel bolt by gluing.

[0011] In some embodiments, the suspension clamp is designed and manufactured based on the hardpoint coordinates of a 3D model of the vehicle suspension.

[0012] In some embodiments, the braking assembly includes a brake disc and a brake caliper.

[0013] In some embodiments, the test bench further includes a angular loading arm, a tilt loading arm, and a rotating drum.

[0014] In some embodiments, the drive shaft is connected to the drive motor via a universal joint.

[0015] A triaxial durability fatigue test method for new energy vehicle wheels and bolts using the system described above includes the following steps:

[0016] S1. Calibration preparation: Fabricate a calibration assembly integrating a dynamic test wheel, wheel bolt axial force strain gauge, and wheel six-component force sensor;

[0017] S2, Road Signal Acquisition: The calibration assembly is installed on the test vehicle for real-vehicle road testing, and signals from the dynamic test wheels, wheel bolt axial force strain gauges and wheel six-component force sensors are collected simultaneously.

[0018] S3. Load spectrum generation: Process the collected road signals to generate a block load spectrum for bench testing;

[0019] S4. Durability and fatigue test: On a broadband response road simulation test bench, triaxial load durability tests of the wheel-tire assembly are conducted in the radial, lateral and longitudinal directions using a block load spectrum.

[0020] In some embodiments, step S3, processing the collected road signals includes: processing the radial, lateral and longitudinal load signals using rainflow counting or level-crossing counting methods, and dividing the loads into load blocks based on the frequency probability of load occurrence.

[0021] In some embodiments, step S4 further includes: comparing the wheel failure location and life calculated by finite element analysis with the physical failure location and life obtained by triaxial limit verification on a broadband response road simulation test bench; if the comparison results do not match, the block load spectrum is corrected, and the process returns to step S3 to re-formulate the load spectrum and conduct the test until the comparison results match.

[0022] In some embodiments, in step S2, the wheel six-component force sensor, the dynamic test wheel, and the wheel bolt axial force strain gauge are simultaneously installed at different wheel positions of the test vehicle in a combined manner to collect signals. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0024] Figure 1 This is a schematic diagram of the technical route of the triaxial durability fatigue testing system for new energy vehicle wheels and bolts of the present invention.

[0025] Figure 2 This is an assembly diagram of the new energy vehicle wheel and bolt suspension and the test equipment fixture of the present invention.

[0026] Figure 3 This is a loading diagram of the triaxial durability fatigue testing system of the present invention. Figure 1 .

[0027] Figure 4 This is a loading diagram of the triaxial durability fatigue testing system of the present invention. Figure 2 .

[0028] Figure 5 This is a schematic diagram of the wheel bolt processing for the triaxial durability fatigue testing system of the present invention.

[0029] Figure 6 This is a report on the simulation analysis results of the load loading of this invention.

[0030] Explanation of reference numerals in the attached figures

[0031] 1. Angle loading arm, 2. Tilt loading arm, 3. Drum, 4. Wheel and tire, 5. Automobile drive shaft, 6. Universal drive shaft, 7. Drive motor, 8. Lower control arm clamp, 9. Upper control arm clamp, 10. Support beam, 11. Mounting plate. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0033] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The following is for reference. Figures 1 to 6 The present invention describes, in conjunction with embodiments, a triaxial durability fatigue testing system and testing method for new energy vehicle wheels and bolts.

[0035] A triaxial durability fatigue testing system for new energy vehicle wheels and bolts includes step 1, calibration preparation, step 2, road signal acquisition, step 3, load spectrum formulation, and step 4, durability fatigue testing. Step 1 is divided into four main parts: dynamic test wheel fabrication, wheel bolt axial force strain gauge fabrication, wheel six-component force sensor preparation, and wheel tire four-bolt assembly. The first three parts are parallel to each other.

[0036] According to one embodiment of this application, the dynamic test wheel fabrication in step 1, calibration preparation, refers to the fabrication of a DMW (Dynamic Measuring Wheel). Its principle is to convert the force signal experienced by the traveling wheel into a strain signal through strain gauge measurement, enabling effective stress analysis of various parts of the wheel. This is a commonly used measurement technique in the industry. Therefore, it includes two steps: FEA (Finite Element Analysis) analysis of wheel stress concentration locations and the attachment of strain gauges to the dynamic test wheel. The strain gauge attachment locations must cover areas with high stress concentration and significant load influence, such as the wheel spokes, rims, and flanges, as determined by FEA analysis. Especially for new energy vehicle wheels, it must also cover locations significantly affected by braking and acceleration torque at the wheel ends, such as bolt holes and center holes. The strain gauges are bridged with electrical wiring and used in conjunction with a remote signal measurement system for acquiring strain signals.

[0037] Because new energy vehicles require a stronger counter-torque during acceleration and braking to overcome enormous inertia, the wheel bolts must withstand extremely high alternating shear and tensile loads. Similar to the DMW principle, the alternating shear and tensile load signals on the bolts are converted into strain signals to achieve strength measurement and analysis. This involves three aspects: wheel bolt machining, bolt axial strain gauge mounting, and strain gauge calibration. Bolt machining refers to drilling holes in the finished wheel bolt core to embed the axial strain gauge. The bolt axial strain gauge mounting technology originated from a Japanese automotive company, where needle-shaped bolt axial strain gauges are pre-embedded in the machined holes in the bolt core and solidified using a specific adhesive. Since wheel bolts are made of high-strength alloy steel, their elastic modulus differs from that of existing wheel materials such as aluminum alloy A356.2. Therefore, stress cannot be converted directly by measuring the strain signal and multiplying it by the elastic modulus. A standard load source and powertrain are needed to apply shear and tensile loads to the fabricated wheel bolts and strain gauges for calibration.

[0038] The Wheel Force Transducer (WFT) collects signals from the three loads and three bending moments experienced by the four components of the wheel and tire during road testing. It is a standard sensor device, but due to different vehicle selections, different sizes of rims and flanges need to be manufactured to match and the Wheel Force Transducer needs to be assembled onto the machined rims to replace normal car wheels. This involves the production of standard rims.

[0039] The above-mentioned various signal acquisition devices, including the dynamic test wheel, wheel bolt axial force strain gauge, wheel six-component force sensor, tire, and wiring, need to be assembled together for signal and acquisition function debugging.

[0040] According to one embodiment of this application, the triaxial durability fatigue testing system for new energy vehicle wheels and bolts includes, in step 2, road signal acquisition, which comprises four progressive steps: road test standard input, road test preparation, calibration wheel installation, and road signal acquisition. The testing vehicle's driving conditions and mileage must be planned and arranged according to relevant regulations and specifications of the road test site and the vehicle's performance and intended use. The driving conditions must include various common reinforced rough roads and durable road surfaces, and the road condition test sequence and number of cycles must be reasonably arranged. Vehicles must be selected based on project development requirements. Of course, most test vehicles are in the new product development stage before mass production; only a unified chassis structure and the ability to install test wheels are required. Other testing needs, such as road test drivers, road test sites, and tools, must also be prepared. The appropriate telemetry devices should be selected and installed according to the signal acquisition requirements. These include the six-component force sensor wheel mounting, the dynamic test wheel mounting, and the axial strain gauge bolt mounting. These three items can be installed simultaneously on different wheel positions or individually in batches for signal acquisition. Generally, a combined installation approach is adopted to maximize testing costs and time efficiency. For example, the six-component force sensor wheel can be installed on the left front wheel (LF), the dynamic test wheel on the right front wheel (RF), and the axial strain gauge bolt on the left rear wheel (LR). It is essential to ensure that the six-component force signal acquisition, wheel strain signal acquisition, and bolt axial strain acquisition are independent and unaffected by interference. Alternatively, they can be integrated into a unified CAN bus for simultaneous signal acquisition.

[0041] The triaxial durability fatigue testing system for new energy vehicle wheels and bolts includes a load spectrum development process in step 3, which consists of seven progressive steps: data signal processing, target damage calculation, load block division, sequence arrangement, equivalent strengthening, load spectrum trial operation, and load spectrum evaluation. The six component force signal processing and load block division are progressive steps, as are the wheel and bolt axial force strain signal processing and target damage calculation.

[0042] According to one embodiment of this application, the standard input for road test road signal acquisition in step 3, data signal processing, refers to the processing of the acquired six-component force signal, wheel strain signal, and bolt axial force strain signal. The six-component force signal processing involves processing the radial load Fz, axial load Fy, and longitudinal load Fx, including but not limited to rain flow counting, level crossing counting, and range pair mean counting methods. Bending moment variable signals Mx, My, Mz and acceleration variable signals Ax, Az are used as references. Wheel speed, mileage, and time are also processed and recorded. Based on the frequency probability of road condition loads, similar loads are compressed, and the random signal source is divided into a load block spectrum with load, speed, time, or mileage elements. Dividing the load spectrum into a block spectrum is more suitable for stable loading on the subsequent durability fatigue test bench.

[0043] According to one embodiment of this application, the triaxial durability fatigue testing system for new energy vehicle wheels and bolts includes step 4, durability fatigue testing, which comprises: fixture design, test component assembly, and triaxial test verification. These three are progressive. Similarly, FEA simulation, analysis matching, and triaxial test verification are also progressive.

[0044] The fixture design is based on the spatial hard point coordinates of the vehicle suspension 3D model, and is designed and manufactured to match the broadband response road simulation test bench. The fixture is required to have sufficient stiffness to accommodate the effects of radial, lateral, and longitudinal loads in the load spectrum. Test component assembly refers to installing specially designed and manufactured fixtures, using the same model of wheels, tires, bolts, and peripheral components as those used in the road test vehicle's data signal acquisition, onto the broadband response road simulation test bench for triaxial testing and verification. Wheel drive axles need to be installed to allow the test bench to apply longitudinal acceleration loads to the wheels, and brake discs and calipers need to be installed to allow the test bench to apply longitudinal braking loads to the wheels. Figure 2 , 5 As shown.

[0045] Triaxial testing verification refers to the durability fatigue test verification of loads applied simultaneously to the wheel-tire assembly in the radial, lateral, and longitudinal axial directions. It requires a broadband response road simulation test bench with relevant testing functions such as power transmission, signal feedback, and logic control. After the durability fatigue test, the sample can be comprehensively evaluated and the results determined. Figure 3 , 4 As shown.

[0046] FEA simulation refers to performing finite element analysis on the wheel using a draft load spectrum generated during the load spectrum trial run. The finite element calculation identifies the stress concentration locations and the most critical fatigue points on the wheel. Triaxial limit verification differs from triaxial test verification. Limit verification involves testing the wheel sample until fatigue crack failure occurs, and the verification life may exceed the target mileage set by the load spectrum. The calculated failure locations from the FEA simulation are compared with the physical test locations from the triaxial limit verification, and the calculated failure life from the FEA simulation is compared with the physical test life from the triaxial limit verification. The load spectrum is analyzed and matched. If the simulation results match the physical test verification results, the load spectrum has passed the final verification and development is successful. If they do not match, the load spectrum must be corrected, and the corrected load spectrum is returned to step 3 for load spectrum trial run, which must meet the loading and testing requirements of the broadband response road simulation test bench. Figure 6 As shown.

[0047] Reference Figure 1 The technical route diagram provides a detailed description of this embodiment: In step 1, calibration preparation, a DMW prototype wheel is fabricated using the same wheel type as that collected during road testing at the test track. The strain gauge attachment locations should cover areas with high stress concentration and significant load influence, such as the wheel spokes, rims, and flanges, as well as each wheel fastening bolt. It is recommended to select 13 strain gauges per wheel. This example demonstrates... Figure 5 A schematic diagram of the wheel bolt processing for a triaxial durability fatigue testing system clarifies the method of drilling bolt holes for fabricating bolt strain gauges. The information on selecting and bonding strain gauges in the embodiments of this invention patent is shown in Table 1 below:

[0048] Table 1 Strain Gauge Information

[0049]

[0050] In step 2, road signal acquisition, this embodiment superimposes the segmented road test acquisition signals according to the relevant road test acquisition standards, and classifies the data according to the road conditions to generate the road spectrum used by the test system, as shown in Table 2 below:

[0051] Table 2. Road Condition Data Collection Sequence and Data Naming

[0052]

[0053] In step 3, load spectrum formulation, data processing software is used to perform level counting processing on the longitudinal load Fx, axial load Fy, and radial load Fz signals of the test track road spectrum data. Based on the frequency probability of each load, similar loads are uniformly planned, and extreme loads with low frequency probability are deleted. The load pairs of Fx, Fy, and Fz after level counting are arranged into a BLOCK. Table 3 below shows the BLOCK load sequence based on the road load spectrum in this example.

[0054] Table 3 BLOCK Load Sequence

[0055]

[0056] Based on the vehicle information collected during the road test and the BLOCK in Table 3, the load values ​​collected by WFT in this case are all load data under a front and rear axle load of 1600kg. Therefore, by dividing the load signal by the wheel load of 800kg, the load spectrum loading coefficient table can be obtained. Table 4 is the broadband response road simulation test bench load spectrum generated based on the road load spectrum BLOCK in this example.

[0057] Table 4. Test Spectrum of Wideband Response Road Simulation Test Bench

[0058]

[0059] The DMW prototype wheel is installed on a broadband response road simulation test bench, and a load spectrum is run on the test machine. Strain data of the DMW prototype wheel is collected simultaneously, strain amplitudes are read, and damage of each strain gauge is calculated. The deviation between the target damage under the test track road conditions in step 2 and the actual damage collected on the broadband response road simulation test bench is compared to determine whether the damage deviation meets the ±10% deviation range requirement. If the deviation range requirement is met, the running load spectrum meets the requirements and can be used as a qualified triaxial durability test load spectrum. If the deviation range requirement is not met, the load spectrum needs to be adjusted by changing the load magnitude, mileage, and sequence order of each component in the load spectrum to adjust the damage of the load spectrum. The adjusted load spectrum is then run again, strain data of the DMW prototype wheel is collected again, and damage calculation and comparison are performed again. This process is repeated until the damage deviation meets the requirements.

[0060] Developing a successful triaxial fatigue test load spectrum for wheels requires not only that the cumulative damage of the wheels meets the deviation requirements, but also that the location of fatigue failure under physical durability limit test is consistent with the simulation prediction location, or that the distribution of the maximum stress location is the same as the simulation analysis location, and that the actual failure mileage is comparable to the simulation analysis mileage.

[0061] In the FEA simulation of the durability fatigue test in step 4, the developed triaxial durability fatigue test load spectrum is used to perform triaxial durability fatigue limit test and failure matching simulation FEA analysis on a broadband response road simulation test bench.

[0062] use Figure 2 The assembly diagram of the suspension and test equipment fixture for new energy vehicle wheels and bolts shows the fixture for installing 1 / 4 chassis component suspension. The fixture shall include a lower control arm fixture 8, an upper control arm fixture 9, a support beam 10, and a mounting plate 11 for suspension support.

[0063] In this embodiment Figure 3 A loading diagram of the triaxial durability fatigue testing system is shown. Figure 1 The test system should include a rotating loading arm 1, a tilting loading arm 2, a rotating drum 3, and wheels / tires 4. Figure 4 A loading diagram of the triaxial durability fatigue testing system is shown. Figure 2 The test system also includes an automotive drive shaft 5, a universal rotating shaft 6, and a drive motor 7.

[0064] If the fatigue failure location of the wheel finally matches the simulation analysis location, and the actual failure mileage is comparable to the simulation analysis mileage (i.e., failure matching), then the triaxial durability fatigue test load spectrum for the wheel has been successfully developed. If the location and mileage are inconsistent or not comparable (i.e., failure mismatch), then the failure is not achieved. Figure 6 If the load loading simulation analysis results report shows that fatigue failure analysis is required, and if non-design reasons such as wheel manufacturing process are ruled out, then it is necessary to return to step 3 of the road load spectrum BLOCK division to generate the triaxial testing machine load spectrum and redo the subsequent load spectrum development work.

[0065] In some embodiments, the triaxial durability fatigue testing system for new energy vehicle wheels and bolts includes: Step 1, calibration preparation: fabricating a dynamic test wheel for measuring wheel strain, a wheel bolt axial force strain gauge for measuring bolt axial force, and preparing a wheel six-component force sensor, assembling them with the tire into a calibration assembly; Step 2, road signal acquisition: installing the calibration assembly on the test vehicle, conducting a real-vehicle road test under preset road conditions, and simultaneously acquiring signals from the dynamic test wheel, wheel bolt axial force strain gauge, and wheel six-component force sensor; Step 3, load spectrum formulation, including: processing the acquired road signals to generate a block load spectrum for bench testing; Step 4, durability fatigue testing, including: conducting radial, lateral, and longitudinal triaxial load durability tests on the wheel-tire assembly using the block load spectrum on a broadband response road simulation test bench; and iteratively correcting the block load spectrum based on the comparison between the test results and the finite element analysis simulation results.

[0066] In step 1, the fabrication of the dynamic test wheel includes: determining the stress concentration locations of the wheel through finite element analysis; and attaching strain gauges to the stress concentration locations, with the locations covering at least the spokes, rim, flange, bolt holes, and center hole.

[0067] In step 1, the fabrication of the wheel bolt axial strain gauge includes: drilling a hole in the core of the finished wheel bolt; pre-embedding the needle-shaped axial strain gauge in the hole and fixing it with glue; and applying shear and tensile loads to the assembled wheel bolt and strain gauge as a whole for calibration using a standard load source.

[0068] In step 2, the wheel six-component force sensor, dynamic test wheel, and wheel bolt axial force strain gauge are simultaneously installed at different wheel positions of the test vehicle in a combined manner to collect signals.

[0069] In step 3, the processing of the collected road signals includes: processing the radial, lateral and longitudinal load signals using rainflow counting and level-crossing counting methods; dividing the loads into blocks based on the frequency probability of load occurrence, and performing sequence arrangement and equivalent enhancement.

[0070] Step 4 includes: using a block load spectrum to perform triaxial limit verification, testing the wheel sample until fatigue crack failure occurs; comparing the failure location and life calculated by finite element analysis with the physical failure location and life of the triaxial limit verification; if the comparison results do not match, the block load spectrum is corrected, and the process returns to step S3 for retesting until the comparison results match.

[0071] Compared with existing technologies, the triaxial durability fatigue testing system and method for new energy vehicle wheels and bolts of the present invention have the following advantages:

[0072] This invention discloses a triaxial durability fatigue testing system and method for new energy vehicle wheels and bolts, outlining a new generation of triaxial durability fatigue testing technology that possesses ultra-high strength, excellent fatigue resistance, and reliable anti-loosening capabilities. It can scientifically and efficiently reproduce triaxial composite loads under real road conditions in the laboratory, accurately evaluating the fatigue durability of wheels and bolts.

[0073] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of this invention and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0074] 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 one or more of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0075] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0076] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A triaxial durability fatigue testing system for new energy vehicle wheels and bolts, characterized in that, The test includes a dynamic test wheel with strain gauges attached to its spokes, rim, flange, bolt holes, and center hole; a wheel bolt axial force strain gauge pre-embedded in the core hole of the finished wheel bolt; a wheel six-component force sensor assembled on the machined rim; and a broadband response road simulation test bench equipped with a suspension fixture for mounting the wheel-tire assembly, the suspension fixture including a lower control arm fixture (8), an upper control arm fixture (9), a support beam (10), and a mounting plate (11); the test bench also includes a drive shaft (5) for applying longitudinal loads to the wheel and a braking assembly; wherein the dynamic test wheel, the wheel bolt axial force strain gauge, and the wheel six-component force sensor can be combined and installed at different wheel positions of the test vehicle; the test bench is used to simultaneously apply radial, lateral, and longitudinal triaxial loads to the wheel-tire assembly mounted thereon based on a block load spectrum developed based on real vehicle road test signals.

2. The triaxial durability fatigue testing system for new energy vehicle wheels and bolts according to claim 1, characterized in that, The wheel bolt axial strain gauge is a needle-shaped axial strain gauge, which is fixed in the core hole of the finished wheel bolt by gluing.

3. The triaxial durability fatigue testing system for new energy vehicle wheels and bolts according to claim 1, characterized in that, The suspension clamp is designed and manufactured based on the hard point coordinates of the 3D model of the vehicle suspension.

4. The triaxial durability fatigue testing system for new energy vehicle wheels and bolts according to claim 1, characterized in that, The braking assembly includes a brake disc and a brake caliper.

5. The triaxial durability fatigue testing system for new energy vehicle wheels and bolts according to claim 1, characterized in that, The test bench also includes a angular loading arm (1), an inclined loading arm (2), and a rotating drum (3).

6. The triaxial durability fatigue testing system for new energy vehicle wheels and bolts according to claim 5, characterized in that, The drive shaft (5) is connected to the drive motor (7) via a universal drive shaft (6).

7. A method for triaxial durability fatigue testing of wheels and bolts of new energy vehicles, employing the system as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Calibration preparation: Fabricate a calibration assembly integrating the dynamic test wheel, the wheel bolt axial force strain gauge, and the wheel six-component force sensor; S2, Road Signal Acquisition: The calibration assembly is installed on the test vehicle for a real-vehicle road test, and signals from the dynamic test wheel, the wheel bolt axial force strain gauge and the wheel six-component force sensor are acquired simultaneously. S3. Load spectrum generation: Process the collected road signals to generate a block load spectrum for bench testing; S4. Durability and fatigue test: On the broadband response road simulation test bench, the wheel-tire assembly is subjected to triaxial load durability tests in the radial, lateral and longitudinal directions using the block load spectrum.

8. The triaxial durability fatigue test method for new energy vehicle wheels and bolts according to claim 7, characterized in that, In step S3, processing the collected road signals includes: processing the radial, lateral, and longitudinal load signals using rainflow counting or level-crossing counting methods, and dividing the loads into load blocks based on the frequency probability of load occurrence.

9. The triaxial durability fatigue test method for new energy vehicle wheels and bolts according to claim 7, characterized in that, Step S4 further includes: comparing the wheel failure location and life calculated by finite element analysis with the physical failure location and life obtained by triaxial limit verification on the broadband response road simulation test bench; if the comparison results do not match, the block load spectrum is corrected, and the process returns to step S3 to re-formulate the load spectrum and conduct the test until the comparison results match.

10. The triaxial durability fatigue test method for new energy vehicle wheels and bolts according to claim 7, characterized in that, In step S2, the wheel six-component force sensor, the dynamic test wheel, and the wheel bolt axial force strain gauge are simultaneously installed at different wheel positions of the test vehicle in a combined manner to collect signals.

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