Standards and methods for electro-hydraulic servo fatigue testing machine in durability testing of automobile manufacturing chassis parts

The automobile chassis is the most complex system subjected to stress in the entire vehicle. Key components such as control arms, steering knuckles, stabilizer bars, and axles continue to bear alternating loads during driving.Electro-hydraulic servo fatigue testing machineWith its technical advantages of large load, high frequency response and multi-channel coordination, it has become the preferred equipment for durability testing of chassis parts in the field of automobile manufacturing.This article systematically introduces the standard system, sample requirements, test methods and selection points of the electro-hydraulic servo fatigue testing machine in automobile chassis testing.

1. Applicable standard system for fatigue testing of chassis parts

Fatigue testing of automobile chassis parts involves three levels: OEM standards, industry standards and national standards:

1. National standards and industry standards:GB/T 15248-2008 "Axial Constant Amplitude Low Cycle Fatigue Test Method for Metallic Materials" is suitable for low-cycle fatigue verification of chassis metal components; GB/T 3075-2020 is suitable for high-cycle fatigue S-N curve determination.

2. Industry standards:QC/T 525-1999 "Automotive Leaf Springs" specifies the fatigue test method for suspension leaf springs; QC/T 1037-2016 is applicable to spiral suspension springs; JT/T 1038 specifies the fatigue test method for axles.

3. OEM standards:The corporate standards of Volkswagen TL series, Toyota TSM series, and BYD Q/BYD series usually require multi-channel coordinated loading to simulate real vehicle roadmaps, and the test conditions are more stringent than the national standard.Under the trend of lightweight new energy vehicles in 2026,Fatigue testing of composite chassis partsDemand has grown significantly, and additional attention needs to be paid to the new national standard GB/T 46220-2025.

2. Chassis parts specimens and tooling requirements

Metal structural parts specimen:Integrated test pieces such as control arms and steering knuckles need to design special fixtures based on the mounting points to ensure that the loading points are consistent with the actual bushing/ball head position.The stiffness of the fixture must be at least 10 times greater than the stiffness of the specimen to prevent the fixture from deforming and absorbing energy.

Multi-channel sample:Large components such as axles and subframes require coordinated loading of 2-6 channels of electro-hydraulic servo, and the phase difference between each channel needs to be accurately controlled (error ≤ 5°) to simulate vehicle turning, braking, bumping and other composite working conditions.

Composite material specimen:Composite chassis parts (such as carbon fiber control arms) need to pay attention to the onset of delamination expansion.According to GB/T 46220-2025 implemented in March 2026, Type I delaminated fatigue specimens need to be prefabricated with a Teflon film sandwich, and the crack growth rate da/dN is recorded under fatigue load.

3. Test methods and loading spectrum

Constant amplitude fatigue test:Load with constant load amplitude, determine S-N curve and fatigue limit.Suitable for material development stage and design verification.

Program load spectrum:Compile multi-level load spectrum according to the actual road spectrum, and load it according to the load-time history programming.It is closer to real usage conditions, and the test results are more meaningful for engineering guidance.

Random roadmap playback:The measured load time history of the test site road is directly collected and played back through the multi-channel electro-hydraulic servo system to simulate the driving conditions of the vehicle.The hot technology trends of 2026 areAI-driven load spectrum compilation, can accelerate the fatigue test by 30%-50%.

4. Precautions for selecting electro-hydraulic servo fatigue testing machine

1. Load range:Select according to the maximum force of the test piece.Passenger car control arms are usually 50-250kN, and commercial vehicle axles can be up to 500-4000kN.It is recommended to work in the range of 10%-80% of the rated force. Long-term full load will affect the life of the equipment.

2. Number of channels:For fatigue testing of a single component, 1 channel is enough; the subframe/axle requires coordination of 2-6 channels; the vehicle-level bench requires more than 16 channels.Douyin’s popular content in 2026 shows:Multi-channel fatigue testing machineIt is one of the fastest-growing search categories in the automotive manufacturing field.

3. Actuator stroke and speed:Chassis parts usually require a stroke of ±50mm or more; the maximum speed of the actuator must meet the product requirement of test frequency × stroke.High frequency and large stroke require high power servo valve.

4. Oil source system:Multi-channel systems need to pay attention to whether the oil source flow is sufficient. The oil temperature control ability directly affects the long-term test stability.It is recommended to configure a constant temperature cooling system to control the oil temperature fluctuation within ±2°C.

5. Data analysis software:It is necessary to support rainflow counting, fatigue cumulative damage calculation (Miner's law), S-N curve fitting and other functions.The trend in 2026 isCloud data management, data from multiple devices can be analyzed centrally.

Shandong Huayan Intelligent Equipment GroupWe provide a full range of 10KN-4000KN electro-hydraulic servo fatigue testing machines and multi-channel coordinated loading systems to serve the durability testing of automobile manufacturing chassis parts.HYYL-4000 multi-oil circuit dynamic hydraulic loading system and six-channel axle fatigue test bench have been put into use by many OEMs and Tier1 suppliers.As the source manufacturer of mechanical testing instruments, we support customization of non-standard tooling and sample testing. Welcome to consult.