Motion reliability test

Motion Reliability Testing Service – Comprehensive Evaluation of Actuator, Joint and Mechanism Durability Under Cyclic and Dynamic Loading

As an ISO/IEC 17025 accredited independent testing laboratory, we offer specialised motion reliability testing services to manufacturers, engineering contractors, and quality assurance teams across the automotive, aerospace, robotics, medical device, industrial automation, and consumer goods sectors. Motion reliability – the ability of a mechanical system, actuator, joint, or linkage to maintain its functional performance, positional accuracy, and structural integrity over a specified number of repeated cycles – is a critical performance parameter for products that involve reciprocating, rotating, sliding, or articulated motion. Our test protocols simulate the cyclic loading, friction, wear, and environmental stresses that occur during the service life of motion components, identifying potential failure modes and ensuring that the product meets its designed service life. All methods are aligned with ISO, ASTM, IEC, EN, and GB/T standards, including ISO 16047 (Fasteners – Torque/angle testing), ISO 1099 (Axial fatigue testing), ASTM D5212 (Cyclic testing of chairs), IEC 60068‑2‑6 (Vibration testing), EN 1312 (Furniture testing), and GB/T 10125 (Corrosion testing). Our inspection and test reports are recognised by the National Medical Products Administration (NMPA), the State Administration for Market Regulation (SAMR), the Ministry of Industry and Information Technology (MIIT), and international certification bodies for product registration, type approval, and quality assurance.

Motion Components and Systems We Regularly Test

Our motion reliability test facilities accommodate a wide range of components and assemblies. Typical test articles include:

• Actuators and linear drives – electric linear actuators, hydraulic cylinders, pneumatic cylinders, and lead‑screw assemblies
• Rotary mechanisms – servo motors, stepper motors, rotary actuators, and geared assemblies
• Hinges, pivots and articulated joints – door hinges, folding linkages, robotic joints, and control linkages
• Sliding and reciprocating components – slides, guide rails, cross‑head assemblies, and reciprocating pumps
• Fasteners and threaded connections – bolts, nuts, screws, and toggle clamps under cyclic loading
• Folding and telescopic mechanisms – folding chairs, telescopic tubes, and scissor lift mechanisms
• Actuator and motor control systems – for evaluating the functional reliability of the entire motion system
• Hydraulic and pneumatic components – valves, accumulators, and hoses under pulsating pressure
• Transportation components – door checkers, seat adjusters, suspension bushes, and steering columns

Cyclic Fatigue and Endurance Testing – Simulating Repeated Motion

• Constant‑amplitude cyclic motion test – ISO 1099 / ASTM E466 – We apply a defined cyclic motion (linear displacement or rotational angle) to the test component at a specified amplitude, frequency (typically 0.5‑10 Hz), and number of cycles (typically 10 000‑1 000 000 cycles). The component is tested in its actual configuration (with the specified load and environment). The test is performed until failure (loss of function, excessive wear, fracture) or until the specified number of cycles is reached. The number of cycles to failure is recorded.
• Variable‑amplitude and block‑cycle testing – for simulating real‑world usage patterns – We apply a sequence of different motion amplitudes (blocks) in a defined order to simulate the variable usage patterns of the component (e.g., typical daily usage, occasional over‑travel). The block sequence is repeated until failure or until the specified number of cycles is reached.
• Accelerated life testing (ALT) – for reducing test time and predicting service life – We increase the frequency, amplitude, or load of the cyclic motion to accelerate the fatigue process, reducing the test time. The acceleration factor is determined using the inverse power law (or the Arrhenius model), and the test results are extrapolated to predict the service life under normal operating conditions.
• Step‑stress testing – for determining the endurance limit and failure threshold – We gradually increase the amplitude (or load) of the cyclic motion in steps (e.g., increasing the angle by 5° every 1 000 cycles) until failure. The test determines the maximum amplitude that the component can withstand for a specified number of cycles (the endurance limit) and the failure threshold.

Friction, Wear and Lubrication Performance Testing – Assessing Surface Degradation

• Friction force and torque measurement – for assessing the energy losses and wear during motion – We measure the friction force (in N) and the friction torque (in N·m) during the cyclic motion test using a calibrated load cell or torque transducer. The friction is monitored over the entire test duration to detect any increase (indicating wear or lubrication breakdown) or decrease (indicating a loss of pre‑load or engagement).
• Wear depth and surface roughness measurement – ASTM D2714 / ISO 6601 / GB/T 12444 – We measure the wear depth (in µm) and the surface roughness (Ra, Rz) of the contact surfaces before and after the cyclic motion test using a profilometer or a white‑light interferometer. The wear rate (in µm per cycle or µm per hour) is calculated.
• Wear debris analysis – for identifying the failure mechanism – We collect and analyse the wear debris (particles) generated during the cyclic motion test, using optical microscopy or SEM‑EDS. The size, shape, and composition of the particles provide insights into the wear mechanism (abrasive, adhesive, fatigue, or corrosion).
• Lubricant degradation – for assessing the performance of greases, oils and lubricating films – We sample the lubricant (grease, oil, or dry‑film lubricant) at regular intervals during the test and analyse it for viscosity, acid number (AN), and the concentration of wear metals (Fe, Cu, Zn). A significant increase in viscosity or acid number indicates lubricant degradation.
• Friction coefficient – static and dynamic – ASTM D1894 / ISO 8295 / GB/T 10006 – We measure the static and dynamic coefficient of friction (COF) between the moving surfaces at the start and end of the test, and at regular intervals. A significant increase in the COF (> 20 %) indicates a deterioration of the lubrication condition.

Environmental and Durability Testing – Simulating Service Conditions

• Temperature‑conditioned cyclic motion test – for assessing the effect of temperature on the motion reliability – We perform the cyclic motion test at elevated temperatures (e.g., 60 °C, 85 °C, 150 °C) and at reduced temperatures (e.g., -20 °C, -40 °C) using a temperature‑controlled chamber. The test assesses the effect of temperature on the material properties (softening, embrittlement) and the lubrication effectiveness (viscosity change).
• Humidity‑conditioned cyclic motion test – for assessing the effect of moisture on wear and corrosion – We perform the cyclic motion test in a high‑humidity environment (e.g., 95 % RH, 40 °C) or in a condensing environment (e.g., temperature cycling with condensation). The test assesses the resistance to corrosion, rusting, and moisture‑induced degradation.
• Salt spray and corrosive environment testing – ASTM B117 / ISO 9227 / GB/T 10125 – For components used in coastal or marine environments, we perform a cyclic motion test in a salt spray environment (5 % NaCl, 35 °C) for 240‑500 hours, and then assess the corrosion, the wear, and the functional performance.
• Dust and contamination testing – for assessing the effect of abrasive particles on the motion – We introduce a specified amount of test dust (e.g., ISO 12103‑1 A2, Arizona dust) into the motion assembly and perform the cyclic motion test. The test assesses the resistance to abrasive wear and the effect of contamination on the friction and the operation.

Positional Accuracy and Backlash Testing – Maintaining Precision and Repeatability

• Positional accuracy and repeatability – for linear and rotary actuators – ISO 230‑2 / GB/T 17421 – We measure the positional accuracy (the difference between the commanded and the actual position) and the repeatability (the scatter of the actual positions) of the actuator or mechanism, using a laser interferometer or a high‑precision linear encoder (resolution 0.1 µm). The test is performed before and after the cyclic motion test to assess any degradation in positional accuracy.
• Backlash measurement – for gearboxes, lead‑screws and joints – ISO 1823 / GB/T 11365 – We measure the backlash (the free play or lost motion) of the mechanism before and after the cyclic motion test, using a dial indicator or a high‑precision angular encoder. An increase in backlash of > 20 % is considered a failure.
• Stiffness and compliance measurement – for assessing the rigidity and stability of the mechanism – We measure the stiffness (the force per unit deflection) of the mechanism under a static load before and after the cyclic motion test. A significant decrease in stiffness (> 20 %) indicates a loss of pre‑load, wear, or deformation.

Failure Analysis and Diagnostic Assessment – Identifying the Mode and Mechanism of Failure

• Visual and dimensional inspection – for detecting cracks, deformation and wear – After the cyclic motion test, we disassemble the component (if required) and perform a detailed visual and dimensional inspection. We inspect the contact surfaces for wear, scoring, galling, or pitting. We measure the critical dimensions (e.g., shaft diameter, bearing internal clearance, gear tooth profile) using calibrated callipers and micrometers.
• Metallurgical and material analysis – ASTM E3 / ISO 4496 – for assessing fatigue and material degradation – For fractured or worn components, we prepare metallographic specimens and examine the fracture surfaces (and the wear surfaces) under an optical microscope and a scanning electron microscope (SEM). We identify the fatigue initiation site, the propagation direction, and the wear mechanism (abrasive, adhesive, fatigue, or corrosive).
• Lubricant analysis – for diagnosing the cause of failure – We analyse the lubricant sample for the presence of wear metals (by ICP‑OES), the particle count (ISO 4406), and the water content (Karl Fischer). The analysis helps to identify the type and severity of the wear process.
• Root‑cause identification and design recommendations – for preventing future failures – Based on the failure analysis, we identify the root cause of the failure (e.g., insufficient lubrication, incorrect material selection, design deficiency, or excessive loading) and provide recommendations for design modifications, material substitution, or improved lubrication.

Regulatory Compliance and Product Certification – Supporting Industry Standards

Our motion reliability testing services are performed in accordance with the most widely used international and national standards. The most commonly requested include:

• ISO 16047 – Fasteners – Torque/angle testing – for assessing the torque‑angle behaviour of threaded fasteners under cyclic loading
• ISO 1099 – Metallic materials – Fatigue testing – Axial force‑controlled method – for axial fatigue testing
• ASTM D5212 – Standard Test Method for Cyclic Testing of Chairs – for furniture durability
• IEC 60068‑2‑6 – Environmental testing – Part 2‑6: Tests – Test Fc: Vibration (sinusoidal) – for vibration testing
• EN 1312 – Furniture – Testing of chairs – Mechanical and structural properties – for chair durability
• GB/T 10125 – Corrosion tests in artificial atmospheres – Salt spray tests – for corrosion testing
• ISO 230‑2 – Test code for machine tools – Part 2: Determination of accuracy and repeatability of positioning of numerically controlled axes – for positional accuracy testing
• GB/T 17421 – Test code for machine tools – Part 2: Determination of accuracy and repeatability of positioning of numerically controlled axes – for positional accuracy testing (Chinese national standard)

Report Acceptance and Regulatory Recognition

All motion reliability tests are conducted under our ISO/IEC 17025 accreditation, using calibrated cyclic testers, load cells, torque transducers, and environmental chambers, all traceable to national and international reference standards. Our final test reports include: a complete description of the test article (component type, material, lubrication, manufacturer), the test method and conditions (motion amplitude, frequency, load, temperature, humidity), the measured parameters (cycles to failure, friction, wear depth, positional accuracy, backlash), a statistical summary (mean, standard deviation, coefficient of variation), a detailed failure analysis (photographs, SEM images, lubricant analysis), and a clear pass/fail verdict against your specified acceptance criteria. These reports are accepted by the National Medical Products Administration (NMPA), the State Administration for Market Regulation (SAMR), the Ministry of Industry and Information Technology (MIIT), and international certification bodies for product registration, type approval, and quality assurance. Bilingual (English/Chinese) versions are available to facilitate submissions to domestic and international authorities and to support your global market access.