In order to make products capable of withstanding harsh vibrations and shocks during actual use, it is necessary to ensure high reliability and enhance their vibration resistance.
To overcome this, to estimate and reproduce difficult-to-measure vibrations and shocks that occur during product use, there are actual vibration and shock reproduction technologies, vibration and shock-resistance design technologies for electrical and electronic equipment, and vibration fatigue analysis evaluation technology.
Shock and vibration resistance gives information concerning the robustness of the mechanical design of a device. The methods for evaluating the vibration resistance are defined in IEC 60068-2-6 and IEC 60068- 2-64.
Electrical and electronic equipment are exposed to vibration in many applications and must withstand this without any degeneration, or even failure, in their function. Therefore, manufacturers of electrical and electronics devices put a great deal of effort into ensuring their instruments are prepared for such applications.
In order to make firm commitments about this and say and prove their equipment is reliable, the manufacturers test their instruments very thoroughly. Vibrations are usually specified in frequency and max. acceleration, the lower the frequency, the greater the deflection needed to achieve the required acceleration. Therefore, below the “crossover frequency”, as it is known, only a specified deflection is tested and defined, rather than an acceleration.
The frequency range in which the electrical and electronic equipment is tested is different. For example on heavy, slowly rotating machinery, primarily frequencies found are from 10 to 55 Hz, but for operation in a rocket, the instrument will be subject to vibration in the frequency range from 10 to 2000 Hz.
Hence, tests are usually conducted in these ranges successively for each of the three spatial axes. The accelerations are specified as a multiple of the acceleration due to gravity [g = 9.81 m/s²] and lie between 2 g for operation on the rotating machinery and up to 20 g with a rocket launch.
We can define vibration resistance as follows: “Vibration resistance specifies up to which acceleration or amplitude in a defined frequency range no malfunction or damage will occur.”
The electrical and electronic devices are vibration resistant if it withstands, undamaged, the vibration that it is exposed to in its “working life”.
In order to make sure the electrical and electronics devices are vibration resistant they need to be vibration tested.
Vibration testing mimics the conditions that a product or structure might see during its lifetime while under a test environment.
Many mechanical vibrations are desirable outcomes of planned design. Loudspeakers are good examples where vibrations are intentional to produce sound. However, some vibrations are undesirable and result from improper design or fair wear and tear on equipment out of balance or improperly tuned.
Whether vibrations are intentional or unintentional, there are precise vibration testing services and vibration testing standards available to verify parameters. These vibration testing facilities can determine whether oscillations are inside or out of tolerable range.
Electrical and electronic products are vibration tested to determine limits and tolerances. Every product is vulnerable to vibration loads and potential breakage or failure. That includes tiny objects like microprocessors and circuit boards right up to giant structures like bridges and skyscrapers.
Vibration testing allows designers, engineers and manufacturers to know what stress limits their product can withstand. Testing through vibrations ensures the product is qualified for its intended purpose and meets safety and regulatory standards, as well as complies with any International Standards Organization (ISO) requirements. Part of due diligence in vibration testing determines fatigue testing, failure limits and structural integrity screening.
Many industries routinely use vibration testing as part of their quality control program. Finding out what vibrations a product withstands before release makes good business sense. Known limitations allow the end user to employ their product safely and put it into trouble-free service.
Testing for vibration resistance prevents product recall, supports warranty conditions and provides excellent product purchase value.
