MIL-STD-1660A APPENDIX A
A.5 CONDITIONING
A.5.1 Test specimen. Unless otherwise specified (see 6.2), no special conditioning of the specimen shall be necessary. The condition of the specimen and any tests performed prior to the vibration test shall be recorded.
A.6 PROCEDURE
A.6.1 Positioning. The specimen shall be placed on but not fastened to the platform. If the specimen might be shipped in other than an upright position, the specimen shall be placed in such a position; and if more than one position is reasonable, the test shall be interrupted and the position changed so that the specimen is tested for equal periods of time in each reasonable shipping position. Midway in the period of time that the specimen is tested resting on each surface, the specimen shall be rotated 180 degrees if the specimen rocks on the platform. Unless failure occurs, the total time of vibration shall be 2 hours if the specimen is tested in one position; and if tested in more than one position, the total time shall be 3 hours.
A.6.2 Restraining devices. Restraining devices shall be attached to the platform to prevent the specimen from moving off the platform and, if necessary, to prevent excessive rocking of the specimen. The restraining devices should be adjusted to permit unrestrained movement of the specimen from its centered position about ½-inch in any horizontal direction.
A.6.3 Frequency. With the specimen in one position, vibrate the platform at ½-inch amplitude (1-inch double amplitude) starting at a frequency of about three cycles per second. Steadily increase the frequency until the specimen leaves the platform (i.e., until a 1/16-inch thick "feeler" may be momentarily slid freely between every point on the specimen and the platform at some instant during each cycle) or until the frequency reaches that at which the maximum platform acceleration is 1±0.1 times the acceleration of gravity. If circular input motion is used, table frequency shall be adjusted to assure that one edge of the unit load leaves the table not less than 3/16 inch on each cycle. This test is normally conducted at an ambient temperature of 70±20 °F. While observing to detect development of any failure, continue to vibrate at such frequency until the total time of vibration in the position is completed. Observe and record whether or not the specimen leaves the platform and the frequency maintained.
A.6.4 Additional positioning. If the specimen is to be tested in more than one position, repeat A.6.3 for each position.
A.6.5 Inspection. After the total period of vibration is completed, inspect the specimen, the packaging, and the contents for evidence of damage. Make appropriate functional or other tests to establish whether or not the item suffered damage.
Source: https://assist.dla.mil -- 2D0ownloaded: 2014-09-28T13:04Z Check the source to verify that this is the current version before use.
For Parts Inquires submit RFQ to Parts Hangar, Inc.
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business