MONOTONIC & CYCLIC TESTING

Material tests are often grouped as monotonic or cyclic. Both types of tests are used to identify the mechanical properties of metals, composites and many other materials, as well as components made from these materials. Tension and compression are examples of monotonic tests. In these tests, an increased load (positive or negative) is applied to the product to identify its yield strength, ultimate strength, and other properties. Cyclic tests administer fluctuating loads, often until there is product failure, using load strategies that may involve either cyclical tension, compression or a combination of the two.

These types of tests establish the capabilities of new product performance, but also over time, look at how problems such as wear and deterioration will affect the product over its lifetime.

This type of testing provides information on:

• Fatigue performance
• Strain gauging
• Stress data
• Temperature
• Prolongation
• Constancy

We have over 54 dedicated doors that are used for only testing and research on-site, which allows us to prepare for any performance issues that may be incurred. Of the 54, 30 are sliding doors and 24 are swing doors. This type of testing and research is very valuable and ensures that the product you receive is going to work every time.

PRODUCTION-LINE BENCH TESTING

Door Controls USA continually tests every product that goes to the customer. Bench testing is completed throughout the production line, and also after the product has been manufactured and assembled.

Different departments such as the Core Department, Rebuild, Electronics and Small Parts each analyze the product through trial runs that measure and determine several possible failures (temperature, noise, full opening, etc.) to confirm that the product is fully functional. Standard repetitions of cycles are an average of 500 oscillations. During 2016, the Electronics Department produced 44,854 controls and the Rebuild Department produced 42, 751 operators that were cyclic bench tested. This return prevention is standard on all products and reduces the need for warranty returns.

These departments come together weekly for meetings and discuss various problems and solutions to issues that some products may incur. Communication between these departments that share information from testing and from customers is a great way of making improvements and passing this benefit to our customers through great quality products and through our technical support.

HIGH-CYCLE FATIGUE TESTING

Fatigue is the process of gradual, restricted and permanent structural change in a material subjected to cyclic loading. Cyclic loading may lead to crack formation, multiplication of cracks and eventually fracture. Fatigue tests are most commonly conducted on smooth bar products or products with a pre-existing crack that grows as the test progresses.

High-cycle fatigue (HCF) tests are typically conducted on smooth bar products in force control. These tests determine the number of cycles to fracture for each product, and the data is compiled. Nominal stress levels in HCF tests are generally low significantly below the material's yield strength. As a result, product lives may last hundreds to millions of cycles, creating a need to conduct HCF tests at high frequencies in order to minimize testing time.