Fatigue Testing/Impact Testing

Fatigue testing and impact testing rely on differing techniques to determine a material’s durability. Fatigue testing machines use a repeated or cyclic load to assess a material’s fatigue strength, endurance limit and fatigue life. Impact testing machines apply controlled impacts to a material to evaluate dynamic strength. Both approaches can help determine the projected lifespan and long-term performance of a material.

Specialized machines are required to carry out fatigue and impact testing. Shimadzu offers a suite of material testing machines, including hydraulic testing machines, which use hydraulic actuators to apply load to the sample material, and advanced electromagnetic systems that rely on the application of quiet electromagnetic force to the sample to determine the material’s durability. You’ll also find servopulser systems, which rely on hydraulics to administer load, while the high-performance servo valve applies impact loads. Shimadzu’s suite of fatigue and impact testing machines is renowned for delivering accurate and repeatable material durability data.

The results of fatigue and impact testing are crucial to a range of industries and applications. For its ability to illuminate potential risks and failures posed by certain materials, this testing data is vital to fields including aeronautical engineering, construction, automotive manufacturing and medical research prioritizing safety and long-term performance.

FAQs

What are the primary indicators measured by a fatigue testing machine?

A fatigue testing machine is designed to quantify three critical benchmarks: fatigue strength (the maximum stress a material can withstand for a specific number of cycles), endurance limit (the stress level below which a material can theoretically endure infinite cycles), and fatigue life (the total number of cycles until failure). By generating an S-N curve (Stress vs. Number of cycles), these machines allow engineers to predict the long-term reliability of components.

When should a hydraulic testing machine be selected over an electromagnetic system? 

The choice between these testing systems is dictated by force requirements and test frequency:

• Hydraulic Testing Machine: Best for high-load, heavy-duty applications (often exceeding 50kN). These use robust hydraulic actuators to test large structural components like steel beams or engine mounts.
• Electromagnetic Systems: Preferred for high-frequency, lower-load tests. Because they operate without oil, they are "cleaner" and quieter, making them ideal for testing medical devices or electronic sensors where precision and speed are more critical than raw force.

What types of materials require testing with an impact testing machine?

An impact testing machine is typically used for metals, polymers, and composites that may be subject to sudden environmental shocks. For example, in the automotive industry, these machines test bumpers and safety glass to ensure they absorb energy during a collision rather than shattering dangerously. This testing ensures that materials remain ductile (flexible) rather than brittle under high-strain rates.