Product Design for Vibration and Shock Testing
(DES 521)
Introduction
Why does a designer need to understand vibration and shock testing? He designs products for use. Will they survive a proposed test? Is that test appropriate?
Orientation
In what engineering situations do vibration and shock damage equipment?
- Review of classical axial dynamic motion - the single-degree-of-freedom (SdoF) model
- The designer needs to understand resonant magnification of input forces; math review
- The designer looks at torsional dynamics
- Designer could try to mitigate vibration and shock
- Designer needs to comprehend data acquisition; displacement; velocity
- Designer appreciation of acceleration & force sensors; possible usage errors
- Designer may need to understand electronic signal processing; possible usage errors
- Designer may question calibration and traceability to national standards
- Moving closer to design of working systems; continuous systems, including beams, plates
- Rotating machinery vibration analysis as introduction to random vibration
- Goals for various vibration tests - why mechanical shakers are long obsolete
- Designer evaluates single electrohydraulic (servohydraulic) shaker systems
- Design review of multiple electrohydraulic shaker systems for multiaxis vibration
- Designer most needs to understand single electrodynamic (electromagnetic) shaker systems
- Designer evaluates multiple electrodynamic shaker systems for multiaxis vibration
- Designer questions power amplifier theory, practice; distortion effects
- Design review of international sinusoidal testing standards; is sine test appropriate?
- Designer assesses software control of sinusoidal testing; neither over- nor under-test
- Designer reviews concept of random vibration; simultaneous excitation of all resonances
- Designer questions random vibration data processing - PSD/ASD, tustin or g2/Hz units; probability
- Designer appraises international standards for random vibration testing
- Designer questions software control of random vibration and acoustic test; neither over- nor under-test
- Designer assesses software control of environmental stress screening (ESS)
- Designer questions accelerated life testing & screening (HALT, HASS)
- Design, fabrication and proper usage of attachment (to shaker and to shock test machine) fixtures
- Design of equipment for vibration and shock testing of oversized and multiple articles
- Designer reviews acquisition of mechanical shock data
- Designer utilizes the shock response spectrum (SRS)
- Designer should understand international shock testing standards; implementation; neither over- nor under-test
- Design benefit of modal analysis and test
