Puck criterion

Recognizing that most failure criteria are limited in their accuracy [8,9], researchers worldwide have undertaken collaborative efforts to evaluate different failure criteria to determine their accuracy and applicability in order to find the best one [10]. These efforts, in particular the worldwide failure exercise in [10], have underlined the fact that despite the large number (over 20) of failure criteria, there is no single one that seems to capture failure of composites accurately for a wide range of loading situations and materials. However, they have pointed out that certain criteria are more accurate and/or have a wider range of applicability than others. Most notable among these are the Puck criterion and the LaRC 03 failure criterion. 

LaRC 03 failure criterion The LaRC 03 failure criterion [12] consists of a family of six criteria. It is an extension of the Puck [11] and Hashin [13] failure criteria. Like the Puck criterion, it focuses on the fiacture plane that is determined by maximizing the Mohr—Coulomb stresses. In the LaRC 03 criterion, failure due to matrix compression is the result of local interaction of shear stresses on a fracture plane. This perspective comes from soil mechanics situafions where the compression strength is different than the tension strength. It is parficularly useful in cases where, on a certain plane in the material, there are both normal and shear stresses acting. The interaction line that... 

Mineral standards were hand crushed to -1/4 inch, then ground to a fine powder in a ball mill (alumina elements) or Bleuler Model 526/LFS678 puck mill. The resultant powder was aerodynamically classified in a Bahco Model 6000 micro particle classifier and the finest fraction ( 18 throttle) was collected. A size criterion of 90% or more by weight of particles 5 micron and smaller in diameter was used for the mineral standards. Sizes were verified by Coulter Counter. Duplicate 13 mm KBr pellets were prepared and the spectra were weight-scaled by techniques similar to those reported by Painter (3) and Elliot (4). With one exception, all the mineral standard spectra were averages of spectra from duplicate pellets. The one exception was the iron sulfate spectrum, which was obtained as the difference spectrum by subtracting the spectrum of HCl-washed weathered pyrite from that of the weathered pyrite. A weight correction was applied to the difference spectrum. 

The viability tests consisted of the establishment of the relative plating efficiency (RPE) and subsequently, the 50% lethal concentration LCjo (or RPE50) by using the colonyforming method on human epithelial cells in culture, the LI 32 cell-line. This test measures quantitatively only one criterion of toxicity which is cell death or cell survival, and consequently is specific, liable, and easily reproducible. It makes possible the ranking of cytotoxic effects of any chemical substance by comparison with the LC50 (Puck and Marcus 1955 Frazier and Andrews... 

Puck A, Kopp J, Knops M. Guidelines for determination of the parameters in Puck s action plane strength criterion. Compos Sci Technol 2002 62 371-8. 

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