DS/EN IEC 60068-2-85:2019

Miljøprøvninger – Del 2-85: Prøvninger – Prøvning Fj: Vibration – Langtidsreplikation


Status:
Gældende
Type:
Standard
Sprog:
Engelsk
Pris fra:
kr. 507,00

Beskrivelse

This part of IEC 60068 demonstrates the adequacy of specimens to resist dynamic loads
without unacceptable degradation of its functional and/or structural integrity when subjected
to the specified vibration test requirements as defined by a time history (Long Time History
Replication). These can either be recorded in measurement exercises or generated artificially.
In both cases, this method allows for generating a test tailored to very specific application.
Typical applications are tests in which very specific deterministic transient, periodical or
random excitation is necessary and the characteristics of the motion are not covered by other
test standards. This includes time histories not sufficiently represented by the standard shock
tests of IEC 60068-2-27 or a general description by a shock response spectrum as in IEC
60068-2-81; periodical vibration that is not covered by a sinusoidal waveform as in IEC
60068-2-6; random vibration that is not covered by the description of Gaussian broad-band
random vibration of IEC 60068-2-64. However, the user shall be aware that long time history
replication uses a deterministic time history. Simulation of random vibration of any kind is
approximated by quasi-random.
In addition, additional mixed mode tests are possible with this test method by generating time
histories that are representations of the required test signals. This includes tests of high
complexity.
The purpose of this test is different from IEC 60068-2-57. The purpose of IEC 60068-2-57 is
an evaluation for a transient vibration using mainly a synthesized time history. A long time
history test is mainly used for a durability and functionality test using an actual time history
measured in a real field environment. It may also be used as a method to apply a simulated
non-gaussian time history.

Long time history replication vibration may be used to identify accumulated stress effects and
the resulting mechanical weakness and degradation in the specified performance. This
information, in conjunction with the relevant specification, may be used to assess the
acceptability of specimens.
This standard is applicable to specimens which may be subjected to vibration of a very
specific nature resulting from transportation or operational environments, for example in
aircraft, space vehicles and land vehicles. It is primarily intended for unpackaged specimens,
and for items in their transportation container when the latter may be considered as part of
the specimen itself. However, if the item is packaged, then the item itself is referred to as a
product and the item and its packaging together are referred to as a test specimen. This
standard may be used in conjunction with IEC 60068-2-47:2005, for testing packaged
products.
If the specimens are subjected to vibration of a deterministic transient or periodic nature
resulting from transportation or real life environments that are covered by other test methods,
these shall generally be preferred. See IEC 60068-3-8:2003 for estimating the dynamic
vibration environment of the specimen and based on that, selecting the appropriate test
method

Antal sider: 30

Udgivet: 2019-09-04

Godkendelsesdato: 2019-08-27

Internationale relationer : EN IEC 60068-2-85:2019 IDT IEC 60068-2-85:2019 IDT

ICS: 19.040 - Miljøprøvning

Varenummer: M323708


Udvalg og komiteer

Komite

  • CLC/SR 104
  • IEC/TC 104

Dansk udvalg

DS/S-604