UN 38.3 Shock Test Data Collection Rich Byczek, Intertek Oct 2013

Transcription

UN 38.3 Shock Test Data Collection Rich Byczek, Intertek Oct 2013
UN 38.3 Shock Test Data
Collection
Rich Byczek, Intertek
Oct 2013
http://www.psessymposium.org/
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T4: Shock
• Small Cells/Batteries = 150g/6ms = consumer
battery specs
• Large Cells/ Batteries= 50g/11ms = automotive
OEM Specs
• Large Cells -> Small Batteries: Cells at 50G,
Battery at 150G
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Measurement Methods
Shipping of Representative shipments and
packaging.
• OEM selected Samples
• OEM selected Methods
• Small, Medium, Large sample shipments
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Measurement Methods
INTERTEK RECOMMENDATIONS
Pallet (LTL) and Small (UPS, FEDEX, etc)
Assume small parcels have the roughest
handling.
Measure at package, not at device (do not
assume dampening)
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Measurement Methods
Measurement Equipment
EDR-3C by IST
- 3axis internal accelerometer
- Use 2 to test both package and
battery.
- Set minimum G threshold, to collect primarily shock pulse
data (i.e. 3G, 5G)
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Measurement Methods
May require multiple runs per shipment size and type.
• Set realistic thresholds to maximize data collection
• Potential variation from shipment to shipment
• Variation based on sample and packages size and
method.
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Measurement Methods
Measurement Analysis
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Convert recorded data to time history
Cursory review of peaks and durations
Data “reduction” based on revised threshold
Statistical calculation of Peak G and Duration
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Measurement Methods
Resultant Shock Pulse ASSUMPTIONS
• Half Sine Pulse
• Small/ Large have separate parameters
• Peak G level: based on max for each shipment size,
regardless of method
• Duration: based on average pulse width above
threshold
• Pulse Count: TBD, based on average pulses per
shipment
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Measurement Methods
NOTE on PEAK and NUMBER of PULSES:
Increasing number of pulses may be a way to reduce
test peak levels.
Typical 1-3 pulse per direction is an ACCELERATED
TEST, and therefore peak G level may not be
representative of actual accumulated stress.
Alternate is realistic G level, with representative test
duration (number of pulses seen in a typical or
multiple shipments)
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Vibration and Shock
• “Test cells and batteries shall be secured to the testing
machine by means of a rigid mount”
• Fixturing:
• Support the product
• May simulate packaging
• May simulate mounting in position
• Not well defined currently.
• Cannot assume package dampening
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Vibration and Shock
• CONSIDER WHAT IS BEING SHIPPED!
• CONSIDER HOW IT IS SHIPPED!
• CONSIDER HOW IT IS TRANSPORTED AFTER INITIAL
SHIPMENT
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THANKYOU
Rich Byczek
Intertek Global Technical Lead
Electric Vehicle & Energy Storage
248-219-1099
[email protected]
Mike Wells
Vibration Test Department Manager
734-582-2900
[email protected]
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