1 - AS 60068.2.64-2003 ENVIRONMENTAL TESTING-TESTS-TEST Fh: VIBRATION, BROAD-BAND RANDOM (DIGITAL CONTROL) AND GUIDANCE
4 - PREFACE
5 - CONTENTS
7 - INTRODUCTION
9 - 1 Object
9 - 2 Normative references
10 - 3 Definitions
10 - 3.1 –3 dB bandwidth,
10 - 3.2 acceleration spectral density
10 - 3.3 bias error:
10 - 3.4 checkpoint:
10 - 3.5 control acceleration spectral density:
10 - 3.6 control system loop:
10 - 3.7 crest factor
11 - 3.8 damping ratio:
11 - 3.9 distortion:
11 - 3.10 drive signal clipping:
11 - 3.11 effective frequency range:
11 - 3.12 error acceleration spectral density:
11 - 3.13 equalization:
11 - 3.14 final slope:
11 - 3.15 frequency resolution:
11 - 3.16 “gn"
11 - 3.17 indicated acceleration spectral density:
11 - 3.18 initial slope:
11 - 3.19 instrument error:
11 - 3.20 multipoint control, averaging:
11 - 3.21 multipoint control, extremal:
12 - 3.22 preferred testing axes:
12 - 3.23 random error:
12 - 3.24 record:
12 - 3.25 reference point:
12 - 3.26 reproducibility
12 - 3.27 response points:
12 - 3.28 root-mean-square value
12 - 3.29 standard deviation,
12 - 3.30statistical accuracy:
12 - 3.31 statistical degrees of freedom
12 - 3.32 sweep cycle
12 - 3.33 true acceleration spectral density:
13 - 3.34 window function
13 - 4 Requirements for testing
13 - 4.1 General
13 - 4.2 Vibration response investigation
13 - 4.3 Testing with random excitation
13 - 4.3.1 Basic motion
13 - 4.3.2 Transverse motion
13 - 4.3.3 Distribution
14 - 4.3.4 Vibration tolerances
14 - 4.3.5 Statistical accuracy
14 - 4.3.6 Frequency resolution
15 - 4.4 Mounting
15 - 5 Severities
15 - 5.1 General
15 - 5.2 Test frequency range
16 - 5.3 Acceleration spectral density
16 - 5.4 Shape of acceleration spectral density curve
16 - 5.5 Duration of testing
16 - 6 Preconditioning
16 - 7 Initial measurements
16 - 8 Testing
16 - 8.1 General
17 - 8.2 Vibration response investigation
18 - 8.3 Low-level excitation for equalization prior to testing
18 - 8.4 Random vibration testing
18 - 8.5 Intermediate measurements
18 - 8.6 Final vibration response investigation
18 - 9 Recovery
18 - 10 Final measurements
19 - 11 Information to be given in the relevant specification
20 - Annex A - Vibration response investigation
20 - A.1 Introduction
20 - A.2 Sinusoidal vibration
22 - A.3 Random excitation
23 - Annex B - Guidance
23 - B.1 General introduction
24 - B.2 Requirements for testing
30 - B.3 Testing procedures
31 - B.4 Equipment normally used with vibration isolators
32 - B.5 Test severities
32 - B.6 Equipment performance
32 - B.7 Initial and final measurements
33 - Annex C - Conversion between percentage values and dB