ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Falling Dart Impact, FDI, toughness is used extensively to characterize the response of plastics to potential abuse. A critical study shows FDI toughness is highly variable with only 68 percent of the test pieces of a typical material failing within ±35 percent of the mean break energy, MBE. If no adjustment for this variability is made, the ASTM accepted “up/down” testing procedure leads to erroneous MBE values. A statistical analysis was carried out which defines the confidence which can be placed in measured MBE's as a function of the number of pieces tested. This analysis shows, for example, that 60 pieces must be tested so that a measured 20 percent difference in MBE's will be significant 90 percent of the time; while if 20 pieces are tested, as is suggested by ASTM, a 35 percent difference is needed before the same level of significance is reached.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760150411
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