1、FORD LABORATORY TEST METHOD EU-BV 060-02 2001 10 31 MEASUREMENT OF DAMPING COEFFICIENT OF SOUND DEADENING MATERIALS Revised Editorial - no technical change A. Cockman Application This method is used to determine the decay rate and decay time of sound deadening materials. Apparatus Required Fixture S
2、ee Figure 4a, b for dimensions, materials and construction. Test Fuel Body sheet steel, size 500 +/- 0.5 x 500 +/- 0.5 x 6 +/- 0.1 mm, surface finish 0.9 - 1.8 micrometre C.L.A. Note: The decay rate of the test panel should be 0.5 dB/second, maximum 0.8 dB/second. Excitation and Measuring Device For
3、 arrangement see drawing. * Beat Frequency Oscillator * Microphone Amplifier * Recorder Oscilloscope * Vibration Pick-up Preamplifier * Pick-up Exciter, see drawing 5 Type 1017 Type 2603 Type 2305 Type 261 5 Type MM0004 * Source: Bruel see Figure 2). The material under test is then applied to the te
4、st panel in accordance with the requirements of the relevant Material Specification and/or drawing with respect to type of application and thickness of material. If the material under test is of the heat curing or heat fusion type, the test assembly is then cured for 1 O minutes at an object tempera
5、ture of 1 1 O OC (thermocouple inserted) unless otherwise required by the relevant Material Specification. Page 2 of 7 Copynght02001, Ford Global Technologies, Inc FORD LABORATORY TEST METHOD EU-BV 060-02 6. After conditioning at 23 +/- 2 OC for 24 h, determine the weight G2 of the test assembly. 7.
6、 The assembly is tested three times as outlined in paragraphs 1 - 3. Note: The recorder paper speed may be increased for materials of high decay rate. Evaluation Determine and record the following: a. Weight of applied material. Where: G = Weight of material applied in g. G, = Weight of uncoated tes
7、t panel in g. G2 = Weight of coated test panel in g. b. Decay time in seconds (see drawing 2). C. Decay rate in dB/second (see drawing 2). The chart record should be attached to the test report. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly.
8、 Each party is responsible for determining proper use and handling in its facilities. Page 3 of 7 Copynght02001, Ford Global Technologies, Inc FORD LABORATORY TEST METHOD EU-BV 060-02 MEASUREMENT OF DAMPING COEFFICIENT OF SOUND DEADENING MATERIALS Test Assembly Vibration Pick-up Preamplifier b 1 - B
9、eat Freauency a . Amplifier Oscillator U- - I I OsciiioscoDe I Recorder Figure 1 Page 4 of 7 Copynght02001, Ford Global Technologies, Inc FORD LABORATORY TEST METHOD EU-BV 060-02 MEASUREMENT OF DAMPING COEFFICIENT OF SOUND DEADENING MATERIALS Switch-off Point dBheC Deca-Rate I I i f I I I 8 1 2 3 4
10、Decay-Time in Seconds Figure 2 Test Assembly a / Nodal Pattern / Support Springs Pick-up Exciter I Figure 3 Page 5 of 7 Copynght02001, Ford Global Technologies, Inc FORD LABORATORY TEST METHOD EU-BV 060-02 MEASUREMENT OF DAMPING COEFFICIENT OF SOUND DEADENING MATERIALS Test Assembly r 32.0 -mir- 50
11、x 50 x ! Dimensions in mm Figure 4 Page 6 of 7 Copynght02001, Ford Global Technologies, Inc FORD LABORATORY TEST METHOD EU-BV 060-02 MEASUREMENT OF DAMPING COEFFICIENT OF SOUND DEADENING MATERIALS Support Spring Spring Steel Total Number of Coils: 9 Da =16mm Dm = 14 mm Dimensions in mm Magnetic Exciter E 78/28 -78.0-m + 26 -3 FI3 - 1 b26.0 nl = 210 - Coil Turns: n2 = 410 n3 = 770 “1 n2 n3 n4 n4 = 1400 Wire: 0.38 mm dia. Max. Current: 0.4 A - 0 Page 7 of 7 Copynght02001, Ford Global Technologies, Inc
