The field of vibration testing, like all other areas of conformity assessment is regulated by a series of testing standards. Vibration testing standards, whether they are industry or international collaborations or are company specific, ensure that when products are tested in accordance with the standard, that they are stressed with appropriate stressors which simulate the end-use environment. This ensures that a product will work successfully and provide acceptable life in that specified environment.
Vibration test standards can be narrowly focused on a very specific end-use environment or cover a broader series of conditions. Many legacy automotive vibration testing standards are good examples of narrowly focused standards. Vibration data from an instrumented vehicle platform would serve as the baseline description of the environment for the test standard. As the vehicle platform matured the standard would be revised to include data from field experience with the platform, but the test standard would still be focused on that one platform.
While they provide very accurate simulations for the platform around which they are based, focused test standards have limited utility to the other vehicles in a product lineup. For this reason, many manufacturers have moved to vibration testing standards which incorporate more broad-based descriptions of the end-use environment, usually obtained from industry or international collaborations like IEC or ISO.
This approach reduces the engineering resources required to develop a vibration testing standard and utilizes a broader cross-section of industry best practices than and individual manufacturer will have internally.
Regardless of the product, a vibration testing standard describes a minimum of five test requirements:
– The frequency range over which the vibration energy will be applied
– The magnitude of the vibration energy
– A description of how the vibration energy will be distributed over the frequency range
– The axes in which the vibration energy will be applied to the product
– The duration of the test
Some vibration testing standards will also add to these basic requirements:
– Minimum vibration fixture dynamic performance
– Locations on the product which will be monitored with accelerometers
– Evaluation criteria for the product
Vibration testing methods are used to execute a vibration testing standard. More on that in our next blog entry.