Aerospace Vibration And Shock Testing
(V&S 510)
Overview for management and participants
- Purpose of environmental testing, particularly vibration and shock
- Purpose of environmental stress screening (ESS)
- Types of vibration tests: resonance search/dwell, fatigue, specification
- Approximate scheduling so managers can audit special topics
Quiz for evaluation of attendee prior knowledge
Classical sinusoidal vibration never observed in service; useful concept
- Introduction: terminology, structural resonant behavior, passive and active isolation
- Sinusoidal vibration measurements: units, sensors, readouts, errors
- Calibration of sensors and systems; traceability to NIST
Most machinery vibration is complex; introduction to spectrum analysis
Sinusoidal vibration testing
- Electrohydraulic and electrodynamic shakers; theory, tradeoffs, limits
- Power amplifier theory, operation, limitations, distortion effects
- Controls for sinusoidal vibration testing
- Sinusoidal vibration test practice
- Interpretation of standards; e.g. MIL-STD-810
- Controversial test methodology: tracking filters, switching and averaging among sensors
- Vibration and shock test fixtures; fixtures for stress screening
- Recommended designs, materials, fabrication methods
- Experimental evaluation before use
- Practical limits: transverse motion; specimen size and weight
Introduction to random vibration
- Sources of random vibration in service and transportation
- No possible equivalence to sinusoidal vibration
- Terminology and definitions
- Spectral density measurement and analysis - the frequency domain
- Probability density - the time domain
Random vibration test practice
- Interpreting and implementing standards, e.g. MIL-STD-810
- Equalization before testing; methods and limits
- Controls
- Electronic protection for test items and shaker system
Combined environment (CERT) testing; reliability tests, e.g. MIL-STD-781
Environmental stress screening (ESS) of electronics hardware production
- Single vs. multi-axis vibration
- Pneumatic repetitive-shock machines
Acoustical environment (intense noise) testing
Instrumentation for measuring shock in service and during tests
- Sensors, readouts, errors
- Calibration
- Shock spectrum analysis; shock response spectrum
Shock testing standards and methods
- Shock testing machines; limitations
- Use of shaker
Witnessing of tests
Course summary; optional final examination; award of certificate.
