Safety Performance Requirements and Test Methods of Automobile Wheels(China National Standards)
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Safety Performance Requirements and Test Methods of Automobile Wheels
1 Scope
This standard specifies the identification, safety performance requirements and test methods of the motor vehicle wheels.
This standard is applicable to the motor vehicle wheels sold on the market and is not applicable to wheels supplied by the vehicle manufacture.
2 Normative References
The following documents are indispensable for the application of this document. For dated reference documents, only the dated versions are applicable to this document. For undated reference documents, the latest versions (including all amendments) are applicable to this document.
GB/T 2933—2009 Wheels and Rims for Pneumatic Tyres -Vocabulary, Designation and Marking
GB/T 2977 Size Designation, Dimensions, Inflation Pressure and Load Capacity for Truck Tyres
GB/T 2978 Size Designation, Dimensions, Inflation Pressure and Load Capacity for Passenger Car Tyres
3 Terms and Definitions
Those defined in GB/T 2933 and the following terms and definitions are applicable to this document.
3.1 Wheels Supplied by the Vehicle Manufacture
The wheels which are equipped with permanent visible trademark of vehicle manufacturer and part number are supplied by vehicle manufacturer.
4 Wheel Identification
The wheel identification shall be permanently visible, and comply with the stipulations in Appendix A of GB/T 2933-2009, which shall cover the following contents at least:
a) Identification marks (name, symbol or trademark) of the wheel manufacturer;
b) Code of rim size designation;
c) Offset distance (mm);
d) Rated load capacity of wheels (kg);
e) Production date (MM/DD/YY).
5 Technical Requirements
5.1 Safety Performance Requirements of Passenger Vehicle Wheels
5.1.1 Dynamic flexural fatigue performance requirements
5.1.1.1 Intensification coefficient and the minimum cycle times
See Table 1 for dynamic flexural fatigue test intensification coefficient and the minimum cycle times.
Table 1 Requirements of dynamic flexural fatigue test intensification coefficient and the minimum cycle times
|
Material |
Intensification coefficient S |
Minimum cycle times |
|
Steel |
1.60 |
30 000 |
|
1.33 |
150 000 |
|
|
Light alloy |
1.60a |
100 000 |
|
1.33 |
270 000 |
|
|
Note: Both the coefficients shall be selected for the steel wheel certification test, and only one of them is selected for the light alloy. |
||
|
a It is the intensification coefficient selected with priority. |
||
5.1.1.2 Failure determination
5.1.1.2.1 Failure determination of steel wheel
The test shall be conducted in accordance with 6.2.1. If any cases below occur to the wheels in the process of test or after completing the minimum cycle times specified in Table 1, the test wheel shall be judged as failure:
a) The wheel cannot continue to bear load;
b) The original crack extends or new visible cracks occur (using dyeing penetration or other acceptable methods, such as zyglo nondestructive inspection method);
c) The offset increment of load point exceeds 10% of the original load offset before reaching the required cycle times.
5.1.1.2.2 Failure determination of light alloy wheels
The test shall be conducted in accordance with 6.2.1. If any cases below occur to the wheels in the process of test or after completing the minimum cycle times specified in Table 1, the test wheel shall be judged as failure:
a) The wheel cannot continue to bear load;
b) The original crack extends or new visible cracks occur (using dyeing penetration or other acceptable methods, such as zyglo nondestructive inspection method);
c) The offset increment of load point exceeds 20% of the original load offset before reaching the required cycle times.
5.1.2 Dynamic radial fatigue performance requirements
5.1.2.1 Intensification coefficient and the minimum cycle times
See Table 2 for dynamic radial fatigue test intensification coefficient and the minimum cycle times.
Table 2 Requirements of dynamic radial fatigue test intensification coefficient and the minimum cycle times
|
Intensification coefficient K |
Minimum cycle times |
|
2.25 a |
500000 |
|
2.00 |
1000000 |
|
a It is the intensification coefficient selected with priority. |
|
5.1.2.2 Failure determination
The test shall be conducted in accordance with 6.2.2. If any cases below occur to the wheels in the process of test or after completing the minimum cycle times specified in Table 2, the test wheel shall be judged as failure:
a) The wheel cannot continue to bear load;
b) The original crack extends or new visible cracks occur (dyeing penetration or other acceptable methods, such as zyglo nondestructive inspection method).
5.1.3 Impact property requirements of light alloy wheel
If any case below occurs after the test of light alloy wheel is conducted in accordance with 6.2.3, the test wheel shall be deemed as failed:
a) The visible cracks cut through the section of wheel center;
b) The wheel center is separated from the rim;
c) All tire pressure is leaked out within 1 min.
If the wheel deforms, or the rim section directly impacted by the hammer has a fracture, the test wheel shall not be deemed as failed.
5.2 Safety performance requirements of commercial vehicle wheels
5.2.1 Dynamic flexural fatigue performance requirements
5.2.1.1 Intensification coefficient and the minimum cycle times
See Table 3 for dynamic flexural fatigue test intensification coefficient and the minimum cycle times.
Table 3 Requirements of dynamic flexural fatigue test intensification coefficient and the minimum cycle times
|
Material |
Diameter code of the rims |
Inner or outer offset distance (mm) |
Performance requirements |
|
|
Intensification coefficient S |
Minimum cycle times |
|||
|
Steel |
13, 14, 15, 16 and larger a |
Less than 101.6 |
1.6 |
60000 |
|
All |
101.6 or larger |
1.10 |
300000 |
|
|
Light alloy |
16 |
127 or larger |
1.35 |
300000 |
|
1.63 |
120000 |
|||
|
17.5 and larger a |
All |
1.35 |
300000 |
|
|
Note: One of the coefficients shall be selected for the wheel with light alloy diameter code of 16. |
||||
|
a Do not include the rims with a diameter of 17.5 and diameters more than 17.5 and width of 266.7 mm (10.5in) and wider rims (wide rim wheel). |
||||
5.2.1.2 Failure determination
The test shall be conducted in accordance with 6.3.1. If any cases below occur to the wheels in the process of test or after completing the minimum cycle times specified in Table 3, the test wheel shall be judged as failure:
a) The wheel cannot continue to bear load;
b) Original crack extends or new visible cracks occur (using dyeing penetration or other acceptable methods, such as zyglo nondestructive inspection method).
c) The offset increment of load point exceeds 15% of the original load offset before reaching the required circulation times.
5.2.2 Dynamic radial fatigue performance requirements
5.2.2.1 Intensification coefficient and the minimum cycle times
See Table 4 for dynamic radial fatigue test intensification coefficient and the minimum cycle times.
Table 4 Requirements of dynamic radial fatigue test intensification coefficient and the minimum cycle times
|
Material |
Code of the rim diameter |
Inner or outer offset distance (mm) |
Performance requirement |
|
|
Intensification coefficient K |
Minimum cycle times |
|||
|
Steel |
13, 14, 15, 16 and 17 (5° drop center rim) |
All |
2.2 |
500000 |
|
15, 16, 17, 18, 20, 22 and 24 (5° flat base rim) |
All |
2.0 |
500000 |
|
|
17.5HC, 19.5, 22.5 and 24.5 (15° drop center rim) |
All |
1.6 |
1000000 |
|
|
Light alloy |
16 |
127 or larger |
2.0 |
1000000 |
|
17.5 and larger |
All |
2.0 |
1000000 |
|
5.2.2.2 Failure determination
The test shall be conducted in accordance with 6.3.2. If any cases below occur to the wheels in the process of test or after completing the minimum cycle times specified in Table 4, the test wheel shall be judged as failure:
a) The wheel cannot continue to bear load;
b) The original crack extends or new visible cracks occur (using dyeing penetration or other acceptable methods, such as zyglo nondestructive inspection method).
6 Test Method
6.1 Test sample
The test samples shall be brand new wheels, and each wheel can only be tested for once.
6.2 Safety performance test method of passenger vehicle wheels
6.2.1 Dynamic flexural fatigue test method
6.2.1.1 Test equipment
The test stand shall be provided with a driven rotation device, so that the wheel can rotate under the fixed bending moment, or the wheel is fixed and bears a rotating bending moment. See Figure 1.
|
Mounting plane |
|
Length of the arm of force |
|
Loading direction |
Figure 1 Sketch Map of Passenger Vehicle Wheel Flexural Fatigue Testing Stand
The loading arm of force shall own enough rigidity and the length shall be within 0.5m - 1.4m. The measurement system can continuously measure the displacement value of the shaft of the arm of force; The accuracy of loading system shall be controlled within ±2.5%.
6.2.1.2 Determination of bending moment
Bending moment M shall be determined as per the formula (1) with the unit of Newton·meter (N·m):
Where:
μ—— It is the set coefficient of friction between the tire and road surface, selecting 0.7;
R—— It is the static load radius of the maximum tire equipped for the wheel, with the unit of meter (m);
d—— It is the inner offset distance or outer offset distance (the inner offset distance is positive, and the outer offset distance is negative.) of the wheel, with the unit of meter (m);
FV—— It is the rated load value of wheels specified by the wheel manufacturer, with the unit of Newton (N);
S—— It is the intensification coefficient (see Table 1).
6.2.1.3 Test steps
6.2.1.3.1 Fix the wheel on the test clamps firmly.
6.2.1.3.2 Use unlubricated double-end bolts and nuts (or bolts) to connect the connecting pieces of test device to the mounting plane of wheel. Keep mounting conditions be equivalent to the actual working conditions on the vehicles. Tighten wheel nuts (or bolts) to the torque value specified by the wheel manufacturer in star shape for tightening. The mounting plane of the connecting pieces of test device and mounting plane of wheel shall be smooth and flat.
6.2.1.3.3 The jerk value of wheel load point with idle load shall not exceed 0.15 mm.
6.2.1.3.4 The wheel bolts and nuts shall be tightened again in the test process.
6.2.1.3.5 The test shall be terminated if the cycle times specified in Table 1 are reached or the wheel is failed.
6.2.2 Dynamic radial fatigue test method of passenger vehicle wheels
6.2.2.1 Test equipment
The testing machine shall be equipped with a device which is capable of exerting a constant radial loading when the wheels are rotating, as shown in Figure 2. It shall be furnished with a driven rotatable drum which has a smooth surface wider than the tire cross-section. It is recommended that the minimum outer diameter of the drum is 1,700 mm. The test device shall make the loading direction be perpendicular to the outer surface of drum, and the loading direction pass the center line of test wheel and drum. The axis of drum shall be parallel to that of test wheel. The accuracy of loading system shall be controlled within ±2.5%.
|
Tire |
|
Radial load Fr |
|
Wheel |
|
Driving drum |
Figure 2 Sketch Map of Radial Fatigue Testing Stand
6.2.2.2 Determination of radial load
The radial load Fr shall be determined as per Formula (2), with the unit of Newton (N):
Where:
FV—— It is the rated load value of wheels specified by the wheel manufacturer with the unit of Newton (N);
K—— It is the intensification coefficient (see Table 2).
6.2.2.3 Test steps
6.2.2.3.1 The test tire shall be selected as per GB/T 2978.
6.2.2.3.2 The tire pressure during the test shall be determined according to working pressure of selected tires. The inflation pressure of test tire shall comply with the values in Table 5.
Table 5 Inflation pressure in the test
The unit is kpa.
|
Working pressure |
Testing pressure |
|
Less than or equal to 160 |
280 |
|
161 to 280 |
450 |
|
281 to 450 |
550 |
|
The testing pressure of the tire shall not be less than 1.2 times of the inflation pressure under the working load. |
|
6.2.2.3.3 Install the wheel tire assembly to the test device, and connect them with unlubricated double-end bolts and nuts (or bolts). Keep the mounting plane of connecting pieces of test devices and wheel mounting plane smooth and flat, and ensure mounting conditions are equivalent to the actual working conditions on the vehicles. Tighten wheel nuts (or bolts) to the torque value specified by the wheel manufacturer in star shape for tightening.
6.2.2.3.4 The wheel bolts and nuts can be tightened again in the test process.
6.2.2.3.5 Tire pressure rise is normal during the test, and it is not required to be adjusted.
62.2.3.6 The test shall be terminated if the cycle times specified in Table 2 are reached or the wheel is failed.
6.2.3 Impact test method of passenger vehicle light alloy wheels
6.2.3.1 Test equipment
The testing machine is equipped with a steel impact hammer that can move along the vertical direction, and the demountable part is suitable to be fastened on the impact hammer device. Width of the impact face shall be at least 125mm, and length shall be at least 375mm, and the seamed edge shall be rounding or chamfering, See Figure 3. The deviation of impact hammer mass m shall be within ±2%, with the unit of kilogram (kg). The calibration mass is 1,000 kg.
Description:
1 - steel impact hammer.
a It is the seamed edge rounding or chamfering, and R5 is recommended for rounding.
Figure 3 Sketch Map of Impact Testing Stand of Passenger Vehicle Light Alloy Wheel
Add calibration mass of 1,000 kg to the site of wheel installation center along the vertical direction through the calibration connecting pieces. See Figure 4. When measuring the center point of steel beam, the deformation along the vertical direction shall be within 7.5 mm±0.75 mm. Supplementary instruction of impact testing machine calibration is shown in Appendix A.
Unit: mm
Description:
1— Steel beam, width × thickness: 200 mm × 25 mm;
2— 1,000 kg calibration load;
3— Calibration connecting pieces;
4— Wheel connecting pieces;
5— Natural rubber support (or equivalents), hardness: 50 shore hardness; diameter: 51 mm; uncompressed height: 27 mm.
a It is used to make 13°available for adjustment;
b It is 13° before calibration;
c Deformation along vertical direction measured at the base.
Figure 4 Impact calibration diagram
6.2.3.2 Determination of impact mass
The impact hammer mass m shall be calculated as per the formula (3), with the unit of kilogram (kg):
Where:
W -- It is the largest static load of the wheel specified by the wheel manufacturer, with the unit of kilogram (kg).
6.2.3.3 Test steps
6.2.3.3.1 The environment temperature shall be kept within 10℃ - 30℃ in the whole test process.
6.2.3.3.2 The tubeless radial tire with the minimum nominal section width suitable to the wheel shall be selected in accordance with GB/T 2978. The inflation pressure is 200 kPa±10 kPa.
6.2.3.3.3 Install the test wheel and tire assembly to the testing machine to make the impact load can be applied to the wheel rim. The axis of wheel shall make an angle of 13°±1° with the vertical direction, and the highest point of wheel flange shall be directly opposite to the impact hammer.
6.2.3.3.4 The mounting conditions of the wheel on the testing machine shall be equivalent to the actual working conditions on the vehicles. Tighten wheel nuts (or bolts) to the torque value specified by the wheel manufacturer in star shape for tightening.
6.2.3.3.5 Enough position on the rim circle of the wheel shall be selected for impact test to ensure the integrity of the central part due to the design diversity of wheel center part. The window and the arm of wheel shall be covered, and the new wheel shall be used for each test.
6.2.3.3.6 The impact hammer shall be placed above the tire, and overlapped with the wheel rim for 25 mm±1 mm. The impact hammer shall be lifted at the place 230 mm±2 mm above the highest point of the wheel rim, then the impact hammer shall be released for impact.
6.2.3.3.7 The judgment shall be conducted in accordance with Article 5.1.3.
6.3 Safety performance test method of commercial vehicle wheels
6.3.1 Dynamic flexural fatigue performance test method
6.3.1.1 Test equipment
The testing machine shall be provided with a driven rotation device, so that the wheel can rotate under the fixed bending moment, or the wheel is fixed and bears the function of a bending moment. See Figure 5. The loading arm of force shall own enough rigidity and the length shall be within 0.76m - 1.4m. The measurement system can continuously measure the displacement value of shaft of the arm of force; The accuracy of loading system shall be controlled within ±5%.
|
Arm of force |
|
Test load |
|
Offset distance |
|
Center line of the rim |
a) 90° Load method (bottom clamping method)
|
Offset distance |
|
Arm of force |
|
Test load |
|
Center line of the rim |
b) 90° Load method (top clamping method)
Figure 5 Sketch Map of Commercial Vehicle Wheel Flexural Fatigue Testing Stand
6.3.1.2 Determination of bending moment
Bending moment M shall be determined as per the formula (4), with the unit of Newton·meter (N·m):
Where:
μ—— It is the set coefficient of friction between the tire and road surface, selecting 0.7;
R—— It is the static load radius of the maximum tire equipped for the wheel, with the unit of meter (m);
d—— It is the inner offset distance or outer offset distance (the inner offset distance is positive, and the outer offset distance is negative.) of the wheel, with the unit of meter (m); If both the inner offset distance and outer offset distance can be used for wheels, then the inner offset distance shall be used;
FV—— It is the rated load value of wheels specified by the wheel manufacturer, with the unit of Newton (N);
S—— It is the intensification coefficient (see Table 3).
6.3.1.3 Test steps
6.3.1.3.1 Fix the wheel on the test clamps firmly.
6.3.1.3.2 Use unlubricated double-end bolts and nuts (or bolts) to connect the connecting pieces of test device to the mounting plane of wheel. Keep mounting conditions be equivalent to the actual working conditions on the vehicles. Tighten wheel nuts (or bolts) to the torque value specified by the wheel manufacturer in star shape for tightening. The mounting plane of the connecting pieces of test devices and mounting plane of wheel shall be smooth and flat.
6.3.1.3.3 The jerk value of wheel load point with idle load shall not exceed 0.30 mm.
6.3.1.3.4 The wheel bolts and nuts shall be tightened again in the test process.
6.3.1.3.5 The test shall be terminated if the cycle times specified in Table 3 are reached or the wheel is failed.
6.3.2 Dynamic radial fatigue performance test method
6.3.2.1 Test equipment
The testing machine shall be equipped with a device which is capable of exerting a constant radial loading when the wheels are rotating, as show in Figure 2. It shall be furnished with a driven rotatable drum which has a smooth surface wider than the tire cross-section. It is recommended that the minimum outer diameter of the drum is 1,700 mm. The test device shall make the loading direction be perpendicular to the outer surface of drum, and the loading direction pass the center line of test wheel and drum. The axis of drum shall be parallel to that of test wheels. The accuracy of loading system shall be controlled within ±5%.
6.3.2.2 Determination of radial load
The radial load Fr shall be determined as per Formula (5), with the unit of Newton (N):
Where:
FV—— It is the rated load value of wheels specified by the wheel manufacturer, with the unit of Newton (N);
K—— It is the intensification coefficient (see Table 4).
6.3.2.3 Test steps
6.3.2.3.1 The test tire shall be selected as per GB/T 2977.
6.3.2.3.2 The tire pressure during the test shall be determined according to working pressure of selected tires. The inflation pressure of test tire shall comply with the values in Table 6.
Table 6 Inflation pressure in the test
The unit is kpa.
|
Inflation pressure under the working load |
Testing pressure of the tire |
|
Less than or equal to 310 |
450 |
|
320 to 450 |
550 |
|
460 to 580 |
690 |
|
590 to 720 |
900 |
|
730 to 830 |
1000 |
|
The testing pressure of the tire shall not be less than 1.2 times of the inflation pressure under the working load. |
|
6.3.2.3.3 Install the wheel tire assembly to the test device, and connect them with unlubricated double-end bolts and nuts (bolts). Keep the mounting plane of connecting pieces of test devices and mounting plane of wheel smooth and flat, and ensure mounting conditions are equivalent to the actual working conditions on the vehicles. Tighten wheel nuts (or bolts) to the torque value specified by the wheel manufacturer in star shape for tightening.
6.3.2.3.4 The wheel bolts and nuts shall be tightened again in the test process.
6.3.2.3.5 Tire pressure rise is normal during the test, and it is not required to be adjusted.
6.3.2.3.6 The test shall be terminated if the cycle times specified in Table 4 are reached or the wheel is failed.
6.4 Damage processing of test fixture device
The damage to the test fixture device and other parts may result in the damage to wheels and invalidity of the test. However, it cannot be the proof for the failure of the test wheels. The test shall be continued after changing all fasteners.
