INTRODUCTION

The function of a vibration system is to provide well defined and reproducible mechanical vibration to a test item, either to simulate a real vibration environment, or to apply vibratory stresses to excite incipient defects, or to study structures. The vibration generator will therefore be designed to provide motion in only one direction, with low distortion, and with displacement, velocity and acceleration capabilities that will cope with most test requirements, within its force capability.

When sizing a system, two pieces of information must be available:

1. Details of the load to be vibrated:

  1. Mass
  2. Shape
  3. Size
  4. Position of its centre of gravity (static & dynamic)
  5. Fixture mass
  6. etc.
2. Test Specification details:
  1. Sine: swept, dwell, resonance dwell test
  2. Random: narrow band/broad band etc.
  3. Bump/Shock test
  4. Sine on random
  5. SRS
  6. etc.

Other considerations

  • System force capability, can it move the largest envisaged test piece to the maximum envisaged test levels?

  • Main performance characteristics, namely displacement, velocity and frequency limitations.

  • Payload support capacity, will external help be needed to physically support the payload?

  • Operating Environment, will it be used in a laboratory by trained staff, or on the factory floor by untrained workers? Are there any restrictions with cooling services for water cooled equipment, is enough water available, and for air cooled systems, can the building accommodate the waste heat? There can be several other factors concerning the operational environment.

  • Type of Application, is it a general purpose test facility that must be versatile, or is it a dedicated production test installation?

    General notes on Sine Ratings  General notes on Random Ratings  General notes on Shock Ratings  Sine Test Worked Example  Random Test Worked Example  V830-335 SPA10K Specification

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