1 - AS 60068.2.57-2003 ENVIRONMENTAL TESTING - TESTS-TEST Ff: VIBRATION-TIME-HISTORY METHOD
4 - PREFACE
5 - CONTENTS
7 - INTRODUCTION
9 - 1 Scope and object
9 - 2 Normative references
9 - 3 Definitions
10 - 3.1 critical frequency
10 - 3.2 damping
10 - 3.3 critical damping
10 - 3.4 damping ratio
10 - 3.5 signal tolerance
10 - 3.6 fixing point
10 - 3.7 Gn
10 - 3.8 high peaks of the response
11 - 3.9 measuring points
11 - 3.9.1 check point
11 - 3.9.2 reference point
11 - 3.10 natural frequency
11 - 3.11 natural time-history
11 - 3.12 oscillator
11 - 3.13 pause
11 - 3.14 preferred testing axes
12 - 3.15 random motion sample
12 - 3.16 required response spectrum
12 - 3.17 response spectrum
12 - 3.18 sampling frequency
12 - 3.19 strong part of the required response spectrum
12 - 3.20 strong part of the time-history
12 - 3.21 sweep cycle
12 - 3.22 synthesized time-history
12 - 3.23 test level
12 - 3.24 test response spectrum
12 - 3.25 time-history
13 - 3.26 zero period acceleration
13 - 4 General requirements
13 - 5 Requirements for testing
13 - 5.1 Vibration response investigation
13 - 5.1.1 Basic motion
13 - 5.1.2 Spurious motion
14 - 5.1.3 Signal tolerance
14 - 5.1.4 Vibration amplitude tolerances
15 - 5.1.5 Frequency tolerances
15 - 5.1.6 Sweeping
15 - 5.1.7 Damping ratio
15 - 5.2 Time- history testing
15 - 5.2.1 Basic motion
16 - 5.2.2 Transverse motion
16 - 5.2.3 Rotational motion
16 - 5.2.4 Tolerance zone for the required response spectrum
16 - 5.2.5 Frequency range
16 - 5.2.6 Calculation of the test response spectrum
17 - 5.3 Mounting
17 - 6 Severities
18 - 6.1 Test frequency range
18 - 6.2 Required response spectrum
18 - 6.3 Number and duration of time-histories
18 - 6.3.1 Number of time-histories
19 - 6.3.2 Time-history duration
19 - 6.3.3 Duration of the strong part of the time-history
19 - 6.4 Number of high peaks of the response
19 - 7 Preconditioning
19 - 8 Initial measurements
20 - 9 Testing
20 - 9.1 General
20 - 9.2 Vibration response investigation
20 - 9.3 Time-history testing
21 - 9.3.1 Single axis testing
21 - 9.3.2 Biaxial testing
21 - 9.3.3 Triaxial testing
21 - 10 Intermediate measurements
21 - 11 Recovery
21 - 12 Final measurements
22 - 13 Information to be given in the relevant specification
29 - Annex A - Synthesis of the artificial time- history: Guidance
29 - A.1 Introduction
30 - A.2 Recommendations for obtaining a required response spectrum (see 6.2)
31 - A.3 Number of high peaks of the response (see 6.4)
33 - Annex B - Test frequency ranges