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This is another part of a series of blog posts concerning the MIL-STD 810 Shock Section, Method 516. This blog was written with reference to MIL-STD-810G w/Change 1 dated 15 April 2014. DES has the experience and expertise to run your MIL-STD-810 test. For more information, please check out our DES shock testing services page and our other MIL-STD-810 shock testing blog articles:
DES recently completed RTCA DO-160Gvibration and shock testing for DB Integrations in Allentown PA, a manufacturer of aircraft components. The testing was performed on ARINC 600 Mounting Trays. The trays were vibration tested for use on fixed wing aircraft (Section 8, Category S) and for use on helicopters (Section 8, Category U2). Shock testing was also performed per Section 7, Category A in RTCA DO-160G. The trays withstood the rigorous testing that took 3 days to complete.
DES has extensive experience performing testing to standards such as RTCA DO-160G. For more information contact DES or call 610.253.6637.
This is part two of a series of blog posts concerning the MIL-STD 810 Shock Section, Method 516. This blog was written with reference to MIL-STD-810G w/Change 1 dated 15 April 2014. DES has the experience and expertise to run your MIL-STD-810 test. For more information, please check out our DES shock testing services page and our other MIL-STD-810 shock testing blog articles:
Shock testing according to Procedure I of MIL-STD 810, Method 516 is intended to test products while they are operating to see if any functional problems occur and to determine if they survive without damage. The applied shocks usually represent those that may be encountered during operational service. This article will focus on the shock test condition when measured field data is not available and the testing will use classical shock impulses. The terminal peak sawtooth is the default classical shock pulse to be used for this condition. Figure 516.7-10 from MIL-STD-810 shows its shape and tolerance limits. Table 516.7-IV contains the terminal peak sawtooth default test parameters for Procedure I -Functional Test. In limited cases a half sine shock impulse is specified. Its shape and tolerance limits are shown in Figure 516.7-12.
This is part one of a series of blog posts concerning the MIL-STD 810 Shock Section, Method 516. This blog was written with reference to MIL-STD-810G w/Change 1 dated 15 April 2014. DES has the experience and expertise to run your MIL-STD-810 test. For more information, please check out our DES shock testing services page.
MIL-STD-810 is a public military test standard that is designed to assist in the environmental engineering considerations for product design and testing. For the purposes of this blog series we will focus on Method 516.7, Shock Testing.
The purpose of shock testing is to:
Evaluate if a product can withstand shocks encountered in handling, transportation, and service environments
Determine the product’s fragility level
Test the strength of devices during a crash situation to verify that parts do not break apart, eject and become a safety hazard
DES successfully completed a challenging combined temperature and vibration test which involved high G levels coupled with extreme temperatures! The vibration conditions required for this test were 10 to 2000 Hz, 20G maximum sinusoidal acceleration. These sinusoidal vibration tests were conducted during temperatures of -54°C and 200°C.
The HAST acronym stands for Highly Accelerated Temperature/Humidity Stress Test and is sometimes shortened to Highly Accelerated Stress Testing. HAST makes use of accelerated temperature and humidity conditions to precipitate failures which could be caused by long term exposure to humid environments.
HAST has been developed to replace Temperature-Humidity-Bias (THB) testing which has typical conditions of 85 ⁰C and 85 % RH along with a bias voltage applied to the sample. A typical THB test time would be 1000 hours. HAST uses increased test temperatures of 110 to 130 ⁰C which decreases the test time to as low as 96 hours compared to a THB test. Thus, by choosing HAST over THB for an accelerated reliability test, testing can be completed in days, not weeks.
Humidity Testing can be used to accelerate the aging of products that are affected by ambient humidity levels. Increasing the humidity above the normal use level humidity can cause defects or failures to occur in shorter times than what would be observed in the field. Humidity testing is most commonly performed along with testing at elevated temperature so that the resulting acceleration factor is affected by both humidity and temperature. The Acceleration Factor (AF) which is the ratio of the life at use conditions to the accelerated life at test conditions for temperature humidity testing is given by the following Arrhenius-Peck equation: