FIXT 501 – Vibration and Shock Test Fixture Design

Introduction of instructor and participants

Overview for management and participants

• Purpose of environmental testing, particularly vibration and shock
• Types of vibration tests: Sinusoidal, random, resonance search/dwell, fatigue, specification
• Types of shock tests: Classical waveform, SRS
• Need to understand vibration before designing fixtures
• Approximate scheduling so managers can audit special topics

Classical sinusoidal vibration never observed in service; but still a useful concept

• Introduction: terminology, structural resonant behavior
• Sinusoidal vibration measurements: units, sensors, readouts, errors

Sinusoidal vibration testing

• Electrohydraulic and electrodynamic shakers; theory, tradeoffs, limits

Introduction to random vibration

• Terminology and definitions
• Spectral density measurement and analysis – the frequency domain

Random vibration test practice

• Interpreting and implementing standards, e.g. MIL-STD-810
• Controls, practice

Environmental stress screening (ESS) of electronics hardware production; HALT, HASS

• Single vs. multi-axis vibration
• Pneumatic repetitive-shock machines

Vibration and shock test fixtures; fixtures for stress screening

• Fixture function defined
• Fixture design requirements
• Recommended designs
• Recommended materials
• Recommended fabrication methods
• Standard fixtures
• Special purpose fixtures
• Control accelerometer location
• Use of multiple control accelerometers
• Experimental evaluation before use
• Use with slip plates and head expanders

Shock testing standards and methods

• Shock testing machines; limitations
• Use of shaker, shock response spectrum (SRS)
• Do not stack resonances
• Isolation, rigidity, analysis

Course summary; optional final examination; award of certificates