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Accelerated life testing is the process of testing a product by subjecting it to conditions (stress, strain, temperatures, voltage, vibration rate, pressure etc.) in excess of its normal service parameters in an effort to uncover faults and potential modes of failure in a short amount of time. By analyzing the product's response to such tests, engineers can make predictions about the service life and maintenance intervals of a product. In polymers, testing may be done at elevated temperatures to produce a result in a shorter amount of time than it could be produced at ambient temperatures. Many mechanical properties of polymers have an Arrhenius type relationship with respect to time and temperature (for example, creep, stress relaxation, and tensile properties). If one conducts short tests at elevated temperatures, that data can be used to extrapolate the behavior of the polymer at room temperature, avoiding the need to do lengthy, and hence expensive tests. == Purpose == ALT is primarily used to speed up tests. This is particularly useful in several cases: * Low failure - Testing even a very large sample at normal conditions would yield few or no failures in a reasonable time. * High longevity - The product must be reliable for a much longer time than can be reasonably tested at normal conditions. * High wear-out - The primary cause of failure occurs over an extended amount of time. For instance, a reliability test on circuits that must last years at use conditions (high longevity) would need to yield results in a much shorter time. If the test wanted to estimate how frequently the circuits needed to be replaced, then the category of low failure would also be applicable. Furthermore, if the circuits wore out from gradual use rather than extreme use (such as a large sudden shock), the wear out category would be involved. If a sudden shock was the primary cause of failure, a Highly Accelerated Life Test may be more appropriate. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Accelerated life testing」の詳細全文を読む スポンサード リンク
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