Random vibration shaker table application

Random vibration shaker table can be applied to the following tests of products:

A) Environmental adaptability test:

Used to verify whether the product can work normally under external environmental conditions. Considering the safety factors of the product, the environmental adaptability test is similar to the vibration functional test(vibration shaker table) of the product. Both use the maximum environmental magnitude that can cover field work during the service life cycle as the test condition. The duration of the test should be sufficient. Complete product functional testing. However, there are also differences between environmental adaptability testing and functional testing:

(1)If the safety factors of the product are not considered, the working conditions during the environmental adaptability test should be the typical workload level during the service life cycle;  
(2)If it is necessary to evaluate the cumulative effect of vibration and environmental factors such as temperature, humidity, altitude or EMI/EMC, all environmental adaptability test items should use the same tested product for assessment.

B) Reliability test:

Used to obtain the statistical failure rate of the product. The ultimate goal is to obtain the mean working time between failures (MTBF value) of the product. The reliability test can be a development test or a qualification test. Reliability testing has many similarities with life testing, but reliability testing can use multiple test samples to be exposed to multiple test sections of the life cycle, instead of using one test sample to be exposed to the entire life cycle like life testing.

C) Cycle life test:

Life test is a real-time, high-precision simulation of the product environmental life cycle. And the decline and failure mentioned above, so the life test is a kind of test that cannot be accelerated, but must test until the product is “bad” (including my test). The difference is that the life test not only focuses on the fatigue damage of the equipment, but also needs to pay attention to Product performance, structural damage and performance failure). Of course, the service life of the product can also be specified and the test can be continued until the predetermined life period. The life test is not limited to the vibration environment with vibration shaker table. When the life analysis before the test is considered to have other environmental factors that have a significant impact on the life, in addition to the vibration environmental conditions, the life test may also include comprehensive environmental factors such as temperature, humidity, and height. , in order to obtain the real life cycle through experiments.

D) Functional test:

Under the worst vibration shaker table's vibration environmental conditions during the product’s environmental life cycle, it assesses whether the product function fails and whether the performance index drops to the point where it cannot complete the work task. Therefore, the environmental conditions for functional testing are usually the maximum possible vibration environment magnitude at the use site during the environmental life cycle. Check the basic performance indicators of the product at the beginning and end of the test, and monitor the basic functions of the product throughout the test process.

E) Development test:

Used to determine the characteristics of the product, expose defects in product design and construction, and provide evaluation and correction instructions. To ensure that the equipment developed can adapt to the life cycle requirements of the vibration environment. Development tests are actually based on the requirements of functional tests, and sometimes also refer to the requirements of environmental adaptability tests.

F) Endurance test:

It is an accelerated fatigue test that represents the entire life cycle of the product. The “accelerated test” method, which uses a higher environmental level than the functional test, is equivalent to the fatigue damage of the equipment, focusing on assessing the damage and fatigue of the product structure. However, the magnitude of acceleration should consider the influence of nonlinearity (such as friction, wear, thermal effects,etc.). Too high magnitude of acceleration will reduce the credibility of the test results.

G) Environmental Stress Screening: 

 Environmental Stress Screening (ESS) is not an environmental test. It is a process used to remove components, parts or components with hidden defects early in the product manufacturing process. The principle of selecting the random vibration power spectral density value is to “can screen out the most potential defects in a short time without causing new damage to the screened items”. Specifically, stress levels higher than the mission profile can be applied for a short period of time, but the design stress limits of the product must not be exceeded.

H) Qualification test: 

Used to determine whether the product can withstand the specified vibration environment requirements. Qualification test actual 1 includes the above functional test and durability test, or a combination of both.