Importance of the Fatigue Testing Procedure 

There is no denying that aerospace giant Boeing has had a tough few months in the headlines. In the very first week of 2024, a 737 jet lost a plug from a rear door in midflight, terrifying passengers and catching the attention of thousands of people on the ground. A few days later, the airline announced it had found more loose parts, which prompted the Federal Aviation Association (FAA) to announce an investigation several days later. It didn’t take long for news about other missing parts and production problems to add to the company’s challenges. 

In April 2024, Boeing released footage of fatigue testing performed in one of its factories as the company scrambled to restore consumer confidence in airline safety. This Boeing story is one high profile example that illustrates the importance of fatigue testing. In this case, it’s an essential step toward both reassuring the public and putting components and materials to the test.  

In most circumstances, fatigue testing is a critical step in the engineering process. It provides critical data regarding the performance and durability of materials and components. The product development team, designers, and engineers can apply that data to refine the design to ensure safety, longevity, and maximum performance. 

Fatigue Testing Measures 

Testing for fatigue is designed to provide specific data points that engineers and designers can use for improvements. Innovative Test Solutions is an industry-leading expert in providing fatigue testing services that replicate real-world environments. Standard testing procedures and custom algorithms and rigs allow for accurate measurement of key details, including: 

• Damage resistance 
• Strength loss 
• Ability to withstand repeat loading 
• Reduction in stiffness 
• Failure 

Implementing Cyclic Forces 

Fatigue testing machines are set up to apply cyclic forces, or set amounts of stress and strain, continually applied until the point of failure. The data generated by cyclic forces testing allows development teams to get a sense of how components and materials will behave in real world environments. In the aerospace industry, for example, it’s a critical step for ensuring safety and reliability. It provides details to inform maintenance plans and to support product safety and the prevention of component failures.  

Types of Fatigue Testing 

Machines are set up according to precise specifications to test how materials such as metals, composites, and other elements will react. Materials undergo testing at varying speeds, loads, and environmental conditions. The two primary types of fatigue testing include low-cycle and high-cycle fatigue testing procedures. 

Low-Cycle Fatigue Testing 

This type of endurance testing uses a low frequency and stress levels above the material’s yield strength. This is often used on components like stationary turbines used in power generation, turbine blades used in the engines of aircraft, and exhaust manifolds in automobiles. It provides details such as strain-life curves, the number of loads withstood before cracking, and ultimately, the number of cycles to failure. 

High-Cycle Fatigue Testing 

This type of fatigue testing uses stress levels below the material’s yield strength and higher frequencies — typically between 20 and 60 hertz. It looks for weak points in materials and measures elements like tensile strength, flexure, and compression. It can simulate high vibration levels, making it an ideal option for materials like gas turbine components. 

Engineer Responsibilities 

The goal of fatigue testing procedures is to learn about materials and components. Whether validating them or putting them through rigorous testing to predict their behavior while in use, the end goal is the same — to capture data. Testing engineers work with testing clients across various industries to apply the appropriate methodologies for the product or material at hand.  

For example, at ITS, our engineers belong to all disciplines and are leaders in their own right. They play an active role in designing tests to meet exacting stipulations. They also provide computer-controlled testing and automated data acquisition. 

Reporting Material Behavior 

Helping product development teams, designers, and engineers understand that data is another facet of the expertise offered by fatigue testing engineers. They take the data and present it to clients, helping them make sense of it as needed. In the end, the material behavior during fatigue testing allows for the refinement of designs. It also provides critical data regarding how long components can withstand the operating conditions before they will require maintenance.  

In the end, the data gleaned from fatigue testing benefits the product design teams, manufacturers, and end users alike.  

Learn More About Fatigue Testing Services with ITS 

Fatigue testing can help prevent airplane parts from spontaneously failing and causing catastrophic losses, but that’s just one of its many uses. ITS is an industry leader renowned for its work with industries such as aviation, oil and gas, medical, transportation, and additive manufacturing, among others. Testing for fatigue is an integral part of the research and development process. It can enhance the end result and provide peace of mind with data that indicates material strength and durability. In a high-stakes environment, that type of reliable data is mission-critical for moving forward.  

Contact ITS today to explore our fatigue testing procedures or to inquire about how our expert team can help you.