Rapid Highly Accelerated Life Testing or Rapid HALT is a reliability test method that is used to expose product weaknesses. A Rapid HALT procedure is a modification of a Classical HALT procedure. For more information about Classical HALT procedures, refer to the following blog articles:
A Rapid HALT is an abbreviated HALT, typically one day of tests, making it a great cost-effective solution for those seeking faster qualitative results. Exposing a product to a Rapid HALT early in the design process can help reduce product development time and cost by enabling manufacturers to identify flaws or areas of improvement before it’s too late.
Rapid HALT’s are a good tool for assessing the reliability of different suppliers of components but can also be used to assess the reliability of less complicated products. For example, DES has performed Rapid HALT’s to evaluate the reliability of different suppliers of power supplies, cooling fans, and LED’s. DES has also performed a Rapid HALT to study different fastening methods in order to determine which was more robust.
Continue reading Rapid HALT – A Cost Effective Alternative to HALT →
A customer approached DES looking to find an accelerated test solution for an AC powered cooling fan used in one of their products. The product had been established in the marketplace and the company was now looking for ways to reduce cost by looking at different cooling fan suppliers. Most fans, however, have a mean life rated for over 20,000 hours, so a typical accelerated life test would require a significant amount of time and money.
Continue reading Cooling Fan Reliability Testing Case Study →
A leading medical technology company contracted DES to perform Product Reliability Testing of a carrying handle. A sample of the test can be seen below and in our video library. The carrying handle had to be pulled, released, rotated and subjected to a sizable lifting force, approximately 20,000 times during its life time.
DES has considerable capability to complete product reliability testing. The main challenge for this project was that each cycle consisted of complex motion. The motion included pulling/releasing the handle to unlatch/latch a pin while rotating the handle. In order to achieve this, DES had to design fixtures and mechanisms that would reposition the carrying handle into each of the designated positions. The number of cycles was automatically counted until failure or 20,000 cycles were completed. During the test, the force to pull the handle was measured at various intervals. The Accelerated Life Testing was completed successfully demonstrating a high reliability.
Please visit our video library to see more examples of DES’s capabilities.
Real world vibrations are usually of the random type. Vibrations from automobiles, aircraft, rockets are all random. A random vibration test can be correlated to a service life if the field vibrations are known. Since random vibration contains all frequencies simultaneously, all product resonances will be excited together which could be worse than exciting them individually as in sine testing. Sometimes random vibrations are mixed with sine vibrations in Sine-on-Random Vibration Testing. Also, a low level of broad band random vibration can be mixed with additional high levels of narrow band random vibrations in Random-on-Random Vibration Testing.
Some common test standards that have specifications for Random Vibration Testing are:
A leading commercial product manufacturer contracted DES to perform Accelerated Life Cycle Testing of a case handle. A sample of the test can be seen below and in our video library. The handle had to be opened and closed many thousands of times during its life time. In addition, two thirds of the cycles had to be completed with the sample exposed to hot and cold temperatures.
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When products are mainly exposed to temperature stresses in the field, Constant Temperature Accelerated Life Testing is used to simulate product life. Products can be tested at temperatures above their normal use temperature during Constant Temperature Accelerated Life Testing in order to accelerate aging. Defects or failure modes that would show up after many years in the field at normal use temperatures can be detected in short times in an Accelerated Life Test. In Constant Temperature Accelerated Life Testing, the typical failure mode is dependent on migration/diffusion or chemical reactions. These types of failures are typically found in electronic components but can also occur in other types of products or materials such as adhesives, batteries, etc. The Arrhenius Equation relates reaction rates to temperature and is used to correlate time in the field at normal use temperature to a Constant Temperature Accelerated Life Test. It should be noted that constant temperature testing will not precipitate failure modes due to thermal cycling. Temperature or thermal cycle testing will be discussed in another blog article.
The Arrhenius Equation that relates reaction rates to temperature is:
Continue reading Constant Temperature Accelerated Life Testing using the Arrhenius Relationship →