Automotive Vibration And Shock Testing

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