Downloaded from https://www.everyspec.com MIL-STD-81OD 19 July\1983 TRANSPORTATION VIBRATION I-3.2-.1 All equipment shipped as secured cargo by land, sea or air will encounter this environment. The test levels are based upon land transport stress levels because these are higher than air or aea stresses, and all air and aea transport scenarios include prior or subsequent land transport. This test is tailorable to”the maximum extent of available data. The test levels shown in figures 514.3-1 thru 514.3-22 represent real, measured stresses.
The land mobile environment is characterized by broadband vibration resulting from the interaction of vehicle suspension and structures with road and surface discontinuitiee. Representative conditions experienced in moving materiel from point of manufacture to end uae are depicted in figure 1 of General Requirements. These condition may be divided into two phasea, common carrier transportation’and mission/field transportation. Common carrier transportation is movement from the manufacturerVa plant to any continental United Statea storage or user installation. This movement is usually accomp- lished by large truck and/or tractor-trailer combination.
Mileage for this transportation generally ranges from 2000’to 4000 miles over improved or paved highwaya.- Mission/field transportation is that movement of materiel as cargo where the platform may be two wheeled trailera, 2-1/2 ton to 10-ton trucke, semitrailers, and/or.tracked vehicles. Typical distances for this phase are 300 to 500 miles. Road conditions for mission/field transport differ from the common carrier’in that, in addition to the paved highway, the vehicles will traverse unimproved roads and.unprepared terrain (off-the-road) under combat conditions. a. Est. levels.
Whenever possible, measured data should be collected on a Variety of large conventional trucks, semitrailers, forklifts ‘withshipping pallete, and conventional flatbed transport vehicles used in the common carrier environment with a realistic load configuration of of the vehicle load capacities by weight. For the miseion/field environment, data are required from typical tactical vehicles, to include: two wheeled trailers, 2-1/2 ton to 10-ton trucks, semi-trailers, and any tracked vehicle capable of or used for transpoit of cargo. This data shall then be ueed to develop test epectra as outlined in appendix A.
If measured data are not available, the vibration inputs contained in figures 514.3-1 thru 514.3-22 may be used. In the development of the vibration test it must be determined if the test item will experience the common carrier, mission/field, or both transportation environmenta. For test items that will only be transported via common carrier, test levels and conditions shall be derived from the measured data of the common carriers or from figures 514.3-1 thru 514.3.3. Test items that will experience both transportation environments should be tested at the higher levele associated with the mission/field transportation.
The levels for this environment can be obtained from Figures 514.3-4 thru 514.3-22. The test muet be developed from a typical miseion/field transportation scenario to obtain the proper mix and representative combination of platform and mileage requirements. . METHOD 514.3 19 July 1983 514.3-5