I Downloaded from https://www.everyspec.com MIL-STD-810D 19 July 1983 I-3.2.2 mblv tra~. In some casea,.it may not be practical or efficient to test large shelters or systems on a shaker. In such cases, transportation conditions may be simulated using the actual transport : vehicle as the vibration exciter. The assemblage may consists of equipment mounted in a truck or trailer, or equipment mounted in a shelter which is then mounted on a truck, trailer, or dolly eet. The exposure consists of traversing the transport vehicle over a prepared teet course until.the teat item has received exposure representative of anticipated deployment scenarios. a. lest leva.
The vibration levele and intensities received by the test item during this test are based upon the course profile and vehicle speeds. aa specified in procedure III. Various road surfaces are to be used, each travereed at speeds which will prOdUCe the desired vibration intensity. --- I TransDort vehicle SDeedS are limited either bv the vehicle‘.ssafe oDeiatinR speed-over a specific course profile or by .th~ speed limit set for ~he spe~ific course. .= ,, b. I@. dur@..m. The test duration shall be as specified in procedure III or until the teet item has received the exposure represenative of the an- ticipated deployment scenarios, whichever is longer. c. i w d& rl .
The test setup shall be as specified in procedure III. The assemblage shall be mounted into the transport vehicle for which it was designed in its deployment configuration. If the assemblage is to be contained in a shelter, it shall be intalled within the ehelter in the deployment configuration. The shelter should be mounted and secured on the transport vehicle(e) that ie normally used for the ehelter under actual transport. Inatrumentation is o provided to measure the vertical axis acceleration time history on the shelter floor and at any other locations of concern.
I-3.2.3 CiabzOrv~ - LOose carzO trauuxxb The loose cargo environment includes conditions experienced by packaged and unpackaged items transported as unsecured cargo on a vehicle traversing irregular surfaces. The oargo has the freedom to bounce,“scuff‘,or collide with other items of cargo or the sides of the vehicle. This environment ia simulated ,inthe laboratory by imparting motion to the test item and allowing it to collide with,restraints established within the teet setup. The test conditions for this environment are, established to a large extent by the equipment used to impart the motion, and the arrangement of the restraints.
This test,has few tailoring options and the selection of ,thetest equipment mtis”t. be based upon the desired end result: . a. lest lev~. Two methods are presented. For both methods the basic movement of the bed of the teat eauinment where the teat item is ulaced ia a ..=. 2.54-cm (l-inch).double-amplitude orbital path at 5 Hz, such as c-m be.obtained on a standard package tester operating in the synchronous mode. (Inthis mode any point on the bed of the package tester will move in a circular path in a ‘-., vertical plane ,per.pendicularto the axes of the shafts.) . . . ., MSTHOD 514.3 19 July 1983 ,514.3-30