Understanding how a Texture Analyser works – Cyclic testing

Cyclic mechanical tests are crucial for understanding the behaviour of materials under repeated loading and unloading conditions. These tests simulate real-world scenarios where materials are subjected to cyclic stresses, such as in automotive components, aerospace structures, and everyday consumer products.

Why are cyclic mechanical tests important?

1. Fatigue analysis: Cyclic tests help determine the fatigue life of materials, which is the number of cycles a material can withstand before failure. This is critical for components that experience repeated loading in their service life.
2. Durability assessment: These tests assess the long-term durability and reliability of materials under cyclic loading, providing insights into how materials will perform over time.
3. Material behaviour understanding: They help in understanding the viscoelastic, plastic, and elastic behaviours of materials under cyclic stresses, which is crucial for designing resilient and long-lasting products.
4. Product safety: Ensuring that materials can endure cyclic loading without significant degradation is essential for maintaining the safety and integrity of products.
5. Optimisation and development: Helps in optimising materials and designs for better performance and longevity by providing detailed data on material behaviour under cyclic conditions.

Cyclic testing options

Within Exponent software there is the ability to choose tests from a library of preconfigured test sequences. There are the following 4 options for cyclic testing:

Cycle Until Count - Go to Distance

The probe, once triggered, advances at the selected speed until the selected distance (Measure Force) has been reached. It then returns to the position that the test was triggered and the procedure repeats, without re-detecting the trigger, for the specified number of cycles (counts). The test can be performed in either Compression or Tension.

Illustration of how a Cycle test works whether its target is
distance/force with a number of cycles or until reset is pressed.

Cycle Until Reset - Go to Force

As above with a target force

Interpreting cyclic mechanical test data

Fatigue life: The number of cycles a material can endure before failure, indicating its fatigue strength.

Stiffness degradation: Changes in stiffness over repeated cycles can indicate material degradation and loss of structural integrity.

Energy dissipation: The energy lost during each cycle, which can provide insights into the material’s damping characteristics and viscoelastic behaviour.

Crack initiation and propagation: Observation of crack formation and growth under cyclic loading helps in understanding failure mechanisms.

Typical applications of cyclic mechanical tests

1. Automotive industry

• Suspension components: Suspension systems in vehicles experience continuous cyclic loading from road irregularities. Testing ensures these components can withstand repeated stresses without failure.
• Engine parts: Components like pistons and crankshafts undergo cyclic stresses during engine operation. Cyclic testing helps in assessing their durability and fatigue life.
• Tires: Tires are subjected to repeated loading and unloading cycles during driving. Cyclic tests help in understanding their wear characteristics and lifespan.

2. Aerospace industry

• Aircraft wings and fuselage: Aircraft structures experience cyclic loading during take-off, flight, and landing. Cyclic tests ensure these components can endure repeated stresses and maintain structural integrity.
• Engine turbines: Turbine blades in jet engines undergo extreme cyclic loading due to high-speed rotation and thermal cycles. Testing helps in predicting their lifespan and preventing catastrophic failures.

3. Construction materials

• Bridges and buildings: Structural components of bridges and buildings experience cyclic loading due to traffic, wind, and seismic activities. Cyclic tests help in ensuring their durability and safety.
• Concrete and steel: Testing these materials under cyclic loading helps in understanding their fatigue behaviour and ensuring long-term structural integrity.

4. Consumer products

• Sporting equipment: Items like bicycles and gym equipment undergo cyclic loading during use. Testing ensures they can withstand repeated stresses and provide safe and reliable performance.
• Electronic devices: Components in electronic devices, such as connectors and switches, experience cyclic loading. Testing helps in ensuring their durability and reliability.

5. Medical devices

• Prosthetics and implants: Medical implants and prosthetic devices are subjected to cyclic loading from body movements. Cyclic tests ensure these devices can withstand repeated stresses and function effectively over time.
• Surgical instruments: Instruments used in surgeries experience cyclic loading during procedures. Testing ensures they can endure repeated use without failure.

Cyclic mechanical tests are essential for understanding the fatigue behaviour, durability, and reliability of materials under repeated loading conditions. These tests provide critical insights for designing safer and more resilient products across various industries, including automotive, aerospace, construction, consumer products, and medical devices. Proper sample preparation, calibration, and controlled testing conditions are crucial for obtaining reliable and meaningful results.

Or if you have lost it, request a 167 page (pdf)  in-depth manual to be sent to you.

There is a Texture Analysis test for virtually any physical property. Contact Stable Micro Systems today to learn more about our full range of solutions.

---

For more information on how to measure texture, please visit the Texture Analysis Properties section on our website.

The TA.XTplusC Texture Analyser is part of a family of texture analysis instruments and equipment from Stable Micro Systems. An extensive portfolio of specialist attachments is available to measure and analyse the textural properties of a huge range of food products. Our technical experts can also custom design instrument fixtures according to individual specifications.

No-one understands texture analysis like we do!

Get in touch to discuss your specific test requirements