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HERHelper (Amtrak station code; Helper, UT)
HERHarvard Educational Review
HERHydrogen Evolution Reaction
HERHigher Education Resources
HERHigher Education & Research
HERHealthy Eating Research
HERHigh Error Rate
HERHuman Exposure Risk
HERHome Equity Release (finance)
HERHealth Economics Research
HERAtlantic Herring (FAO fish species code)
HERHard Error Rate
HERHollow Earth Radio (online radio)
HERHeavy Equipment Rentals LLC (California; est. 1999)
HERHole Expansion Ratio (mechanical testing)
HERHIV Epidemiology Research
HERHigh Efficiency Red (LED)
HERHyperemesis Education and Research
HERHeraklion, Crete Island, Greece - Heraklion (Airport Code)
HERHigh Explosive Research (UK nuclear weapons development)
HERHearing Examiner Recommendation
HERHip Hop in its Essence and Real (hiphop/rap artist Common Sense)
HERHydroxyethylrutoside (also seen as HR)
HERHead End Restriction (railways)
HERHousehold Energy Regional Project (Intermediate Technology Development Group)
HERHazards and Effects Register (Offshore Energy and Mineral Management Environmental Program; US DOI)
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References in periodicals archive ?
The comparison showed that depending on the input parameters for the laser cutting, it is also possible to produce an edge with lower Hole Expansion Ratio (HER) than the one for a blanked hole.
et al., "Improving Hole Expansion Ratio by Parameter Adjustment in Abrasive Water Jet Operations for DP800," SAE Int.
The hole expansion ratio (HER) is calculated based on the initial and final diameters of the hole:
Where [D.sub.o] and [D.sub.f] are the initial and final specimen hole diameters, and [lambda] is the hole expansion ratio. [D.sub.f] is the average of two perpendicular caliper measurements [crack location(s) avoided].
The hole expansion ratio ([lambda]) is generally regarded as a relative "local formability" parameter with limited application to edge-cracking analysis and prediction.
Additionally, three practical failure criteria based on the lower-bound hole expansion ratio are introduced.
Therefore, a practical lower-bound hole expansion ratio is
where [[mu].sub.[lambda]]' and [[sigma].sub.[lambda]]' are the mean and standard deviation of the hole expansion ratio (outliers removed), and [[lambda].sub.LB] is the lower-bound hole expansion ratio.
The maximum edge stretch ([e.sub.max]) is equivalent to the lower-bound hole expansion ratio:
As mentioned in the Introduction, [lambda] represents a condition beyond failure; however, [[lambda].sub.LB] represents a conservative value that is well-below the average hole expansion ratio. Furthermore, near fracture sites on HE test specimens, local strains could be higher than the average value represented by [lambda], and thus, any failure criterion based on [[lambda].sub.LB] may be considered doubly conservative.
For this material, the average hole expansion ratio ([[mu].sub.[lambda]]) was 35.0% with a standard deviation ([[sigma].sub.[lambda]]) of 4.4% (n = 5).
The calculated lower-bound hole expansion ratio ([[lambda].sub.LB]) was 30.8%.