Fracture maps

Finally, the question arises whether it is possible to correlate the fractures mapped in the rocks of the Teistengrunnen Group to the established events of the tectonic history of the southwestern Barents Sea. Since the deposition of the sediments of the Teistengrunnen Group in the late Callovian (locally late Ba-thonian) to the early Ryazanian (Dalland et al., 1988), the different structural elements of the study area un-... 

Lecampion, B. and Gunning, J. Model selection in fracture mapping from elastostatic data. International Journal of Solids and Structures 44(5) (2007), 1391-1408. 

Brook, C.A. and Aiison, T.L. 1986. Fracture mapping and ground subsidence susceptibiiity modeiiing in covered karst terrain the exampie of Dougherty County, Georgia. Proceedings of the Third International Symposium on Land Subsidence, Venice, internationai Association of Hydroiogical Sciences, Pubiication No. 151,595-606. 

P.W.R.Beaumont, J.K. Wells and P.D.Angtice, Development of fracture maps for fibrous composites, Proc.37 Annual Techn. Conf. Reinforced Plastics, Composites Institute, Jan. 11-15, 1982, 20 A, 1. 

Our SRM results are also consistent with 30 years of test data from a variety of sources (Table 1). Indeed, our experience with the six billets studied for the SRM as well as billet E, and data from the old stress rupture and fracture map work cited earlier, suggests that NC 132 actually did have billet-to-billet variability after all. Other investigators have commented on variability between and within billets, but often furnished no concrete data or stated that the variation could not be correlated with any observable microstructural variations or inhomogeneities." " ... 

This is illustrated in Eig. 2.30 [2.167]. The surface was that of a fractured compact of SiC to which horon and carhon had been added to aid the sintering process. The aim of the analysis was to establish the uniformity of distribution of the additives and the presence or absence of impurities. The Auger maps show not only very non-uniform distribution of boron (Eig. 2.30a) but also strong correlation of boron with sodium (Eig. 2.30c), and weaker correlation of boron with potassium (Eig. 2.30b). Point analyses for points A and B marked on the images reveal the presence of sulfur and cal-... 

Composite materials have many distinctive characteristics reiative to isotropic materials that render application of linear elastic fracture mechanics difficult. The anisotropy and heterogeneity, both from the standpoint of the fibers versus the matrix, and from the standpoint of multiple laminae of different orientations, are the principal problems. The extension to homogeneous anisotropic materials should be straightfor-wrard because none of the basic principles used in fracture mechanics is then changed. Thus, the approximation of composite materials by homogeneous anisotropic materials is often made. Then, stress-intensity factors for anisotropic materials are calculated by use of complex variable mapping techniques. 

CASE 2 - Evaluation of the importance of structural anisotropies (fractures, faults, cataclastic bands) and their persistence (horizontal and vertical) measured at the surface (structural-geological survey) and their mapping (integrated evaluation of geophysical data and structural-geological data)... 

Fig. 6.12. Toughness maps depicting contours of predicted fracture toughness (solid lines in kJ/m ) for (a) glass-epoxy composites as a function of fiber strength, Uf, and frictional shear stress, tf and (b) Kevlar-cpoxy composites as a function of at and clastic modulus of fiber, Ef. The dashed line and arrows in (a) indicate a change in dominant failure mechanisms from post-debonding friction, Rif, to interfacial debonding, Sj, and the effect of moisture on the changes of Of and Tf, respectively. Bundle debond length...

Wells J.K. and Beaumont P.W.R. (1982). Construction and use of toughness maps in a fracture analysis of the micromechanisms of composite failure. In Composite Materials Testing and Design. ASTM STP 787 (I.M. Daniel ed.), ASTM, Philadelphia, PA, pp, 147-162. 

Fig. 2. SEM-BSE image and EPMA maps from Esfordi deposit, a) White crystals in fractures are REE minerals, b). RE minerals (sketched by black colour) are interstitial to actinolite (gray parts), c) RE minerals (black) and apatite (white) EPMA map.

Fig. 14.5. An optical micrograph and stress maps in bovine femoral bone near a fracture. The map in (a) was acquired at zero applied stress and in (b) at critical stress for crack propagation. The net stress field was obtained by subtracting (a) from (b) and is shown in (c). Reprinted with permission from [48]...

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