Vibration tests

Both these levels are indicated in Table 11.3. For more details and for conducting the vibration test, reference may be made to lEC 60034-14. 

The CBMS II was exposed to the full temperature and supply voltage specification range in chamber tests and also to vibration tests several times during the development program. In extensive tests at HSSS in 2002, the CBMS II was equilibrated in chambers at ambient (+68°F/+20°C), cold (+32°F/0°C), and... 

The formula applies to results from both long-term creep and short-term forced vibration tests, but by itself provides a poor fit at longer durations. 

Test cell A rotating test ring is partially submersed into fuel stationary test ball with applied load is lowered onto rotating test ring. A test disk is immersed into fuel a vibrating test ball with an applied load is lowered onto the test disk. 

Hj) Height of Burst (Sonic) Test. The purpose of this test is to det the height of burst of a fuze using sonic techniques. This technique requires the measurement of the time of arrival of sound at directional microphones precisely placed in a plane. A brief description of this test is given on p IIIB-20 Ref 39 Addnl info can be obtd from "Instrumentation Section, Technical Services Laboratory, Ammunition Development Division, Ammunition Engineering Directorate, Picatinny Arsenal, Dover, NJ 07801 H2) Hydraulic Ram and Vibrator Test. This test could be used to simulate impact shock on bombs or rockets assembled with fuzes that are launched from aircraft. It also could check the transportability of fuzes that experience this environment. This test is listed, but not described in Ref 39, p IIB-37... 

P) Random Vibration Test. This test is used to det the effect of random vibration on fuzes that are used in missiles or carried by jet aircraft. No description of test is given on p IIB-38 of Ref 39... 

Ohart (Ref 9, p 380-82) describes the following tests for packing containers with fuzes or other explosive items a) Vibration Test. In this test a packing container with fuzes or other items is strapped or fastened to a flat vibrating surface for a given period of time, usually 4 hrs. The frequency of vihration is 550 cycles per min, and the entire platform moves accdg to a 1/8 inch eccentric cam... 

A.H. Erickson, Ordn 38, 1050-52(1954), Fuze Testing Standards (Tests for fuzes include jolt test, jumble test, vibration test, 40-foot test and other tests) (These tests are described in MIL-STD-331, listed here as Ref 41)... 

Transportation Vibration Test 104 is briefly described in Vol 4, p D1098-L R. Its revision in Change Notice 1 (24 July 1967) supersedes MIL-STD-331, p 1 of 10, January 1966 (8 pages)... 

Vibration Tests. Vibration tests are conducted in metal tubes (1-3/8 inches by 7/16 inch) which are capped at both ends. The vibration tester used is a model SAC vibrator from MF Manufacturing Co. In each test, duplicate samples are vibrated for 24 hours while a third is kept stationary for the same period as a control. Tests are usually performed at 300 c.p.s. and 5 g and 1000 c.p.s. and 3 g although these conditions can be varied. At the conclusion of each test, samples of the slurry are removed from the top and bottom of each tube and analyzed for solids content. 

Vibration Tests. The Transportation Vibration-Temperature Test (Ref 3) is mandated by the US Dept of Defense in development and production of fuzes. It applies to designs which reached the development phase after 1 November 1973. 

Those designs which were in the development phase prior to 1 November 1973 were subjected to the Transportation Vibration Test (Test 104) of Ref 1... 

Three (3) conditions are required for the.test (a) 73° 18° F, (b) 160°F, and (c) -65°F. There shall be three (3) groups of fuzes, one group for each temperature. The fuzes and their vibration test fixtures shall be pre-conditioned at the test temperature for a minimum of four (4) hours prior to the vibration test, and shall be maintained at that temperature for the duration of the test. If data exists showing a different stabilization time, then this shall be used instead of the four (4) hours. After changes of fuze orientations, the external surface temperature of the fuze shall be returned to the specified temperature before the test may be resumed... 

The vibration test levels for Procedure 2 shall be the same as for Procedure 1 with a total test time of six (6) hours (2 hours per axis)... 

Sequential testing may be considered during development in addition to Procedure 1. The vibration test durations may be six (6) hours (2 hours per axis) at room temperature and three (3) hours (1 hour per axis) at each temperature extreme for a total test time of 12 hours for the three (3) temperatures. The temperature sequence of room temperature —65°F and 160°F is recommended... 

MPT 4-2-804, Laboratory Vibration Tests , US Army Test Evaluation Command, Aberdeen Proving Ground, Maryland 21005... 

To obtain consistent and reproducible results it is normal practice to mechanically condition tests pieces before forced vibration tests. ISO 4664 advises scragging for at least six cycles at the maximum strain and temperature to be used in the test series followed by recovery at room temperature for at least 12 hours. 

Panels of 24-ST alclad aluminum, 6x6 inch 0.032 sage, are coated with the fire-retardant system (only one surface) and placed in the vibrating test rig. 

Tests based on forced vibrations are preferred when parts are being designed. The relationships are still very complex and only approximate. If experimental tests can be carried out close to actual service conditions, better results can be obtained. Forced vibration testing is detailed as follows. 

With some experiments a stress is imposed, such as with creep tests and with vibrations in which the sample is subjected to a periodic stress. With other experiments the deformation is given and the resulting stress is being measured, such as with stress relaxation and with vibration tests with an imposed periodic strain. The results of these two different types of methods cannot directly be translated into each other but only by complex transformations, in other words ... 

The ball drop test, vibration test and heat test were carried out but at no time did any of the sample generators ignite. 

FTMA is a forced vibration test method based on direct measurement of stress and strain spectra. As with all forced vibration methods, FTMA is subject to spurious wave effects at high frequencies. The lower frequency limit is determined by transducers, signal conditioners, etc. The lower limit in this research was 35 Hz as determined by the inherent properties of the piezoelectric transducers. With different transducers (for example load cell for the force and LVDT for displacement measurements) and signal conditioners, FTMA should measure material properties down to much lower frequencies. 

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