Reasons for choosing our testing services
ZHONGXI Testing has obtained inspection qualification certifications from multiple countries and regions worldwide. We possess a senior testing team and advanced testing methods, providing independent, impartial, and professional third-party verification services for global carbon projects.
Internationally recognized authority
Certified by multiple international standards such as CNAS, VCS, and GS, with reports universally applicable worldwide.
Global service capability
Covering 140+ countries and regions, it supports on-site detection and remote verification in multiple languages.
Professional experimental methods
Adopt standard experimental methods to ensure accurate and reliable data.
Before sending samples for constant amplitude fatigue testing, most engineers ask a fundamental question: does this laboratory cover my material? The answer is typically yes. Our extensive testing capabilities span metals, polymers, composites, and coatings, with rigorous adherence to ASTM, ISO, EN, and GB standards. We assess materials under various loading conditions, including tension, compression, bending, and cyclic shear, to ensure reliability in your application scenarios. This service is essential for evaluating fatigue life, determining failure modes, and validating material performance in repetitive stress environments.
Testing Scope
Our constant amplitude fatigue testing services are applicable to a wide range of products, including but not limited to: structural steel,, titanium alloys, stainless steels, engineering plastics, fiber-reinforced composites, and specialized coatings. Materials are tested in multiple grades and variants, such as heat-treated or weld-affected zones, to address specific application requirements. Common scenarios include aerospace components, automotive parts, medical devices, and industrial machinery. The testing is often referenced against standards such as ASTM A499, ISO 11950, EN 207, and GB/T 7704, ensuring alignment with global engineering practices.
Testing Items and Parameters
Testing items include cyclic loading tests, stress-life (S-N) curves determination, fatigue crack growth evaluations, and fracture mechanics assessments. Typical parameters for fatigue testing are outlined in the table below:
| Test Type | Typical Parameters | Graded Limit Requirements |
| Cyclic Loading | Frequency range: 0.1 Hz to 10 Hz; Maximum stress: 0.1σu to 0.9σu | Relative deviation within ±5% between parallel samples |
| S-N Curve | Number of cycles: 103 to 107; Stress ratio (R): 0 to 1 | Interpolation error within ±10% for fatigue life prediction |
| Fatigue Crack Growth | ΔK range: 10 to 100 MPa·m1/2; Growth rate: 10-8 to 10-2 mm/cycle | Measurement accuracy within ±15% of measured values |
Graded limits are defined based on material specifications and industry benchmarks, ensuring results are statistically valid and comparable across different batches.
Data and Variation Analysis
Parallel-sample and batch-to-batch variation is rigorously assessed through statistical analysis of test data. Relative deviation between parallel samples is calculated as the standard deviation divided by the mean, expressed as a percentage. For cyclic loading tests, the acceptance window for relative deviation is typically ±5%, ensuring consistency in material performance. In S-N curve determination, interpolation errors are limited to ±10%, allowing accurate fatigue life predictions. Batch-to-batch variation is analyzed using ANOVA (Analysis of Variance) to identify trends and ensure reproducibility. Typical acceptance windows for batch-to-batch variation are ±15%, aligned with international standards for material variability reporting.
Results are presented with clear variation metrics, enabling engineers to make data-driven decisions. The capability narrative emphasizes precision, reproducibility, and adherence toISO 17025 guidelines, ensuring confidence in the test outcomes.
Confirm your required testing items and sample information. We will revert with a formal quotation and expected schedule.