Том 16 (2013)

Directional dissimilarity of transitional functions: Surface energy density factor

G.C. Sih1,2

1Lehigh University, Bethlehem, PA, 18015, USA
2East China University of Science and Technology, Shanghai, 200237, China

Scale segmentation of the SI system of measurement has necessitated the use of transitional function for connecting the results of the segmented scales. The state-of-the-art of measurement in the 1800s is reflected by the coarseness of scale segmentation. By up-to-day standard of nanonization, scale refinement is necessary to account for the interactive benefits of multiscaling, the building block of which is dual scaling, say macro-micro or micro-nano. The directional dissimilarity between two adjacent scales, say macro ® micro and micro ® macro, arises naturally in physical processes.

An index L is defined to measure the severity of directional dissimilarity that may prevail in the surface energy density factor (SEDF) for macro ® micro. A similar index W applies to micro ® macro. Both L and W reflect the combined effects of loading, material and geometry. The macro-micro transition of SEDFmacro can differ from the micro-macro transition of SEDFmicro. The relation between the macrostress intensity factor and SEDFmacro is incompatible with that for the microstress intensity factor and SEDFmicro. The stress intensity factor, a monoscale concept, will not hold for both the macro- and microscale. To begin with, the units may differ. The same holds for the surface energy density factor. The irreconcilability can be resolved by an argument of dimensional compatibility, provided that the agreement is to preserve the monoscale definitions. These considerations call for a scrutiny of the crack growth data whose scatter may be contributed by the directional effects of scale transition.


стр. 7 – 13

Образец цитирования:
G.C. Sih  Directional dissimilarity of transitional functions: Surface energy density factor // Физ. мезомех. - 2013. - Т. 16. - № 4. - С. 7-13