Downloaded from https://www.everyspec.com MIL-STD-81OD’” 19 July 1983 MSTHOD 516.3 SHOCK SECTION I : Eaes I-l PURPOSE......:.. . .. . . . . . . I-2 ENVIRONMENTAL EFFECTS . . . . . . . . . . . I-3 GUIDELINES FOR DETERMINING TEST PROCEDURES ,. . . . .. .. . . 516.3-1 .: . . . . . . . . 516.3-1 AND TEST CONDITIONS. .. . . . . . . . I-4 SPECIAL CONSIDERATIONS. . . . . . . .-. . . I-5 REFERENCES . . . . . . . . . .. . . . . SECTION II . . . . . . . . 516.3-1 . . . . . . . . 516.3-17 . . . . . . . . 516.3-17 11-1 APPARATUS . . . . . . . . . . II-2 PREPARATION”FOR”TES; : . . . .... . . . . . II-3 PROCEDURES . . . . . . . . . . . . . . . . II-4 INFORMATION TO BE RECORDED . . . . . . . . . . . . . .
. . 516.3-18 . . . . . . . . 516.3-19 . . . . . . . . 516.3-20 . . . . . . . . 516.3-25 SECTION I I-1 ~. Shock tests are performed to asaure that materiel can withstand the relatively infrequent nonrepetitive shocks or transient vibrations encountered in handling, transportation, and service environments. Shock tests are also used to measure an item1s fragility, so that paokaging may be designed to protect it, if necessary, and to test the strength of devices that attach equipment to platforms that can craah. 1-2 ~. Mechanical shocks will excite an equipment item to respond at both forced and natural frequencies. things, can cause: This response, among other a.
Failures due to increased or decreaaed friction, or interference between parta. b. Changea in dielectric strength, loss of insulation resistance, variations in magnetic and electrostatic field strength. c. Permanent deformation due to overstresa. d. More rapid fatiguing of materiala (low cycle fatigue). I-3 NOTE: This test method should be applied at the end of the tailoring proceaa diacribed in section 4 of this standard. a. . . ~. This method is applicable to all materiel which may be subjected to mechanical shock during its life cycle. b. ~. None. c. ~.
There are often advantages to applying shock and vibration teats before climatic testa, provided that this sequence represents realistic service conditiong. Test experience haa ahown that climate-sensitive defects often ahow up more clearly after the application of shock and vibration forces. METHOD 516.3 516.3-1 19 July 1983