Under normal conditions it may take years to gather failure data on the life cycle of new products. Through accelerated life testing the overall time to failure can be reduced to weeks by increasing the frequency of the field loads and by removing insignificant stress components. In addition, life cycle testing on a product can be reduced or accelerated dramatically by increasing the stress levels to higher than normal. Putting a product through Accelerated Life Testing can reduce test time from weeks to days while still achieving satisfactory results saving both time and money. We have the knowledge and experience to develop a custom reliability test plan, accelerate test time, build a custom test setup, run the test, and analyze results!
What are the different Accelerated Life Tests that DES can perform?
- Qualitative Accelerated Life Testing
- Quantitative Accelerated Life Testing (QALT)
- Accelerated Aging or Shelf-Life Testing
Qualitative Accelerated Life Testing
Qualitative Accelerated Life Tests such as HALT or MEOST do not demonstrate a service life or a mean time between failure (MTBF). They use a combined environment of extreme stresses to quickly expose a product's design and manufacturing weaknesses. The stresses start at normal levels and then increase until failures are found, or material limits are reached. After the weaknesses are exposed during testing, engineers can improve the design to make their products more reliable. DES performs Qualitative Accelerated Life Testing on a wide range of aerospace, commercial, medical, and military products.
Quantitative Accelerated Life Testing
Quantitative Accelerated Life Tests, sometimes called (QALT), are meant to demonstrate a service life or MTBF. Typically, a custom test plan is developed to determine what stresses to use and what stress levels to apply. This is based upon the product’s application and the types of stresses it will see in the field. It is preferred to run QALT at accelerated stress levels to reduce test time. DES recommends performing HALT prior to QALT to determine how high the stress levels can be accelerated before creating unrealistic failure modes. It is also desired to continue QALT until some failures occur which make the reliability calculations more accurate. After the QALT test, the results are analyzed and a service life or MTBF is estimated. DES has developed test plans, built custom test setups and performed QALT on aerospace, commercial, medical, and military products.
Accelerated Aging or Shelf-Life Testing
DES can perform Accelerated Aging to ASTM F1980: Accelerated Aging of Sterile Barrier Systems and Medical Devices. Aging tests using ASTM F1980 are typically performed on medical products or items where an acceptable shelf life needs to be determined. Accelerated aging or shelf-life testing is performed in a chamber at elevated temperature typically with controlled humidity. By testing items at more extreme conditions than they will normally experience, you can evaluate how they will age under normal conditions in a reduced amount of time. After the aging test is completed, the products are evaluated for degradation.
The aging test time in ASTM F1980 is determined by
- Choosing an accelerated test temperature
- Calculating an Accelerated Aging Factor (AAF)
- Computing the aging test duration by dividing the normal storage duration by the AAF.
DES has a lot of experience performing these calculations and can help you with determining the aging test parameters.
So if you need help with Accelerated Product Life Testing or Accelerated Aging, please contact us because we are testing experts and our lab is accredited!
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