Automotive Vibration And Shock Testing
(V&S 511)
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
Quiz for evaluation of attendee prior knowledge
Classical sinusoidal vibration never observed in service; useful concept
- Introduction: terminology, structural resonant behavior
- Sinusoidal vibration measurements: units, sensors, readouts, errors
- Calibration of sensors and systems; traceability to NIST
Most machinery vibration is complex; introduction to spectrum analysis
Introduction to sinusoidal vibration testing
- Electrohydraulic and electrodynamic shakers; theory, tradeoffs, limits
- Power amplifier theory, operation, limitations, distortion effects
- Analog and digital controls for sinusoidal vibration testing
- Sinusoidal vibration test practice
- Interpreting and implementing SAE and other standards
- Controversial test methodology: tracking filters, switching and averaging among sensors
- "Buzz, squeak and rattle" investigations and testing
Introduction to random vibration
- Sources of automotive random vibration; 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 SAE and other standards
- Equalization before testing; methods and limits
- Quick review of analog with most emphasis on digital controls
- Multi-axis testing
Combined environment (CERT) testing; reliability tests, e.g. MIL-STD-781
Environmental stress screening (ESS); accelerated testing
Shock and vibration test fixtures; fixtures for stress screening
- Recommended designs, materials, fabrication methods
- Experimental evaluation before use
Instrumentation for measuring shock in service and during tests
- Sensors, readouts, errors; calibration
- Shock spectrum analysis; shock response spectrum
Shock testing standards and methods
Witnessing of tests
Summary of course for management and participants
