MIL-STD-202H.pdf - 第118页
MI L - S TD - 202 - 20 4 4. 3.3 Sweep t ime and dur at i o n. T he ent i r e f r equ enc y r a nge of 10 t o 2 , 000 H z and r e t ur n t o 10 Hz shall be traversed in 20 minutes . T hi s c y c l e s ha l l b e per f or …
MIL-STD-202-204
METHOD 204
VIBRATION, HIGH FREQUENCY
1. SCOPE
1.1 Purpose. The high frequency vibration test is performed for the purpose of determining the effect on
component parts of vibration in the frequency ranges of 10 to 500 hertz (Hz), 10 to 2,000 Hz or 10 to 3,000 Hz, as
may be encountered in aircraft, missiles, and tanks. The choice of test condition A, B, C, D, E, F, G, or H should be
based on the frequency range and the vibration amplitude dictated by the applications of the component under
consideration, and the state of the component part in relation to resistance-to-vibration damage.
2. APPLICABLE DOCUMENTS
This section not applicable to this standard.
3. DEFINTIONS
This section not applicable to this standard.
4. GENERAL REQUIREMENTS
4.1 Mounting. The specimens shall be mounted as specified. For specimens with attached brackets, one of the
vibration test directions shall be parallel to the mounting surface of the bracket. Vibration input shall be monitored on
the mounting fixture in the proximity of the support points of the specimen.
4.2 Test condition A (10g peak). The specimens, while deenergized or operating under the load conditions
specified, shall be subjected to the vibration amplitude, frequency range, and duration specified in 4.2.1, 4.2.2, and
4.2.3, respectively (see figure 1).
4.2.1 Amplitude. The specimens shall be subjected to a simple harmonic motion having an amplitude of either
0.06-inch double amplitude (maximum total excursion) or 10 gravity units (g peak), whichever is less. The tolerance
on vibration amplitude shall be ±10 percent.
4.2.2 Frequency range. The vibration frequency shall be varied logarithmically between the approximate limits of
10 and 500 Hz (see 4.10), except that the procedure of method 201 of this standard may be applied during the 10 to
55 Hz band of the vibration frequency range.
4.2.3 Sweep time and duration. The entire frequency range of 10 to 500 Hz and return to 10 Hz shall be traversed
in 15 minutes. This cycle shall be performed 12 times in each of three mutually perpendicular directions (total of 36
times), so that the motion shall be applied for a total period of approximately 9 hours. Interruptions are permitted
provided the requirements for rate of change and test duration are met. Completion of cycling within any separate
band is permissible before going to the next band. When the procedure of method 201 of this standard is used for
the 10 to 55 Hz band, the duration of this portion shall be the same as the duration for this band using logarithmic
cycling (approximately 1-1/3 hours in each of three mutually perpendicular directions).
4.3 Test condition B (15g peak). The specimens, while deenergized or operating under the load conditions
specified, shall be subjected to the vibration amplitude, frequency range, and duration specified in 4.3.1, 4.3.2, and
4.3.3, respectively (see figure 1).
4.3.1 Amplitude. The specimens shall be subjected to a simple harmonic motion having an amplitude of either
0.06-inch double amplitude (maximum total excursion) or 15g (peak), whichever is less. The tolerance on vibration
amplitude shall be ±10 percent.
4.3.2 Frequency range. The vibration frequency shall be varied logarithmically between the approximate limits of
10 to 2,000 Hz (see 4.10), except that the procedure of method 201 of this standard may be applied during the 10 to
55 Hz band of the vibration frequency range.
1
北测（上海）电子科技有限公司
联系方式：xuyj@beice-sh.com 13917165676
MIL-STD-202-204
4.3.3 Sweep time and duration. The entire frequency range of 10 to 2,000 Hz and return to 10 Hz shall be
traversed in 20 minutes. This cycle shall be performed 12 times in each of three mutually perpendicular directions
(total of 36 times), so that the motion shall be applied for a total period of approximately 12 hours. Interruptions are
permitted provided the requirements for rate of change and test duration are met. Completion of cycling within any
separate band is permissible before going to the next band. When the procedure of method 201 of this standard is
used for the 10 to 55 Hz band, the duration of this portion shall be the same as the duration for this band using
logarithmic cycling (approximately 1-1/3 hours in each of three mutually perpendicular directions).
4.4 Test condition C (10g peak). The specimens, while de-energized or operating under the load conditions
specified, shall be subjected to the vibration amplitude and frequency range shown on figure 1. The tolerance on
vibration amplitude shall be ±10 percent.
4.4.1 Part 1. The specimens shall be tested in accordance with method 201 of this standard for 6 hours; 2 hours in
each of three mutually perpendicular directions.
4.4.2 Part 2. The specimens shall be subjected to a simple harmonic motion having an amplitude varied to
maintain a constant peak acceleration of 10g (peak), the frequency being varied logarithmically between the
approximate limits of 55 and 2,000 Hz (see 4.10). The entire frequency range of 55 to 2,000 Hz (no return sweep)
shall be traversed in 35 ±5 minutes, except that in the vicinity of what appears to be resonance, and in order to
facilitate the establishment of a resonant frequency, the above rate may be decreased. If resonance is detected,
specimens shall be vibrated for 5 minutes at each critical resonant frequency observed. This procedure shall be
performed in each of three mutually perpendicular directions. Interruptions are permitted provided the requirements
for rate of change and test duration are met.
4.4.3 Resonance. A critical resonant frequency is that frequency at which any point on the specimen is observed
to have a maximum amplitude more than twice that of the support points. When specified, resonant frequencies shall
be determined either by monitoring parameters such as contact opening, or by use of resonance-detecting
instrumentation.
4.5 Test condition D (20g peak). The specimens, while de-energized or operating under the load conditions
specified, shall be subjected to the vibration amplitude, frequency, range, and duration specified in 4.5.1, 4.5.2, and
4.5.3, respectively (see fig. 1).
4.5.1 Amplitude. The specimens shall be subjected to a simple harmonic motion having an amplitude of either
0.06-inch double amplitude (maximum total excursion) or 20g (peak), whichever is less. The tolerance on vibration
amplitude shall be ±10 percent.
4.5.2 Frequency range. The vibration frequency shall be varied logarithmically between the approximate limits of
10 to 2,000 Hz (see 4.10), except that the procedure of method 201 of this standard may be applied during the 10 to
55 Hz band of the vibration frequency range.
4.5.3 Sweep time and duration. The entire frequency range of 10 to 2,000 Hz and return to 10 Hz shall be
traversed in 20 minutes. This cycle shall be performed 12 times in each of three mutually perpendicular directions
(total of 36 times), so that the motion shall be applied for a total period of approximately 12 hours. Interruptions are
permitted provided the requirements for rate of change and test duration are met. Completion of cycling within any
separate band is permissible before going to the next band. When the procedure of method 201 of this standard is
used for the 10 to 55 Hz band, the duration of this portion shall be the same as the duration for this band using
logarithmic cycling (approximately 1-1/3 hours in each of three mutually perpendicular directions).
4.6 Test condition E (50g peak). The specimens, while de-energized or operating under the load conditions
specified, shall be subjected to the vibration amplitude, frequency, range, and duration specified in 4.6.1, 4.6.2, and
4.6.3, respectively (see figure 1).
4.6.1 Amplitude. The specimens shall be subjected to a simple harmonic motion having an amplitude of either
0.06-inch double amplitude (maximum total excursion) or 50g (peak), whichever is less. The tolerance on vibration
amplitude shall be ±10 percent.
2
北测（上海）电子科技有限公司
联系方式：xuyj@beice-sh.com 13917165676
MIL-STD-202-204
G = .0512f
2
DA (f = frequency in hertz, DA = double amplitude in inches.)
FIGURE 1. Vibration-test curves.
3
北测（上海）电子科技有限公司
联系方式：xuyj@beice-sh.com 13917165676