A comparison of mineral grain fabrics and finite strain in amphibolites from eastern Finland

1981 ◽  
Vol 18 (6) ◽  
pp. 995-1003 ◽  
Author(s):  
Denis Gapais ◽  
Jean-Pierre Brun
Keyword(s):  
Finite Strain ◽  
Strain Analysis ◽  
Simple Correlation ◽  
X Ray ◽  
Gneiss Domes ◽  
Strain Pattern ◽  
Strain Ellipsoid ◽  
Eigenvalue Method ◽  
General Strain ◽  
Eastern Finland

Fabrics in amphibolite rocks from the Kuopio area (eastern Finland) are described and compared with results of finite strain analysis. The area consists of mantled gneiss domes, which are deep-seated diapiric structures. Results concern the cover rocks of the domes. Strain ellipsoids range in shape from prolate to oblate (−0.67 ≤ v ≤ 0.52). Strain intensities vary strongly [Formula: see text].Preferred orientations of hornblende have been measured by X-ray texture goniometry and corresponding fabric ellipsoids calculated using an eigenvalue method. The same has been done for biotite where present. Fabric ellipsoids obtained for biotite are all oblate (0.04 ≤ vf ≤ 0.76). Those obtained for hornblende range from prolate to oblate (−0.60 ≤ vf ≤ 0.73). Intensities of hornblende fabric [Formula: see text] are weaker than those of biotite fabric [Formula: see text]. Local variations of results are induced by grain-scale factors, such as grain size, or original fabrics. No simple correlation is found between intensities of fabric and strain. In general, increasing strains are probably accompanied by an increase of the oblateness of biotite fabric ellipsoids. Hornblende fabrics are found to give a good approximation of the prolateness of the finite strain ellipsoid. The resulting L–S tectonite pattern is consistent with the general strain pattern and with the development of domal structures in the Kuopio area.

Strain Analysis in Thin La1−xCaxMnO3 Films by Grazing Incidence X-ray Scattering

1999 ◽  
Vol 602 ◽  
Author(s):  
M. Petit ◽  
L. J. Martinez-Miranda ◽  
M. Rajeswari ◽  
A. Biswas ◽  
D. J. Kang ◽  
...  
Keyword(s):  
Film Thickness ◽  
Lattice Mismatch ◽  
Compressive Strain ◽  
Strain Analysis ◽  
Grazing Incidence ◽  
Relaxation Processes ◽  
Near Surface ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

AbstractWe have performed depth profile analyses of the lattice parameters in epitaxial thin films of La1−xCaxMno3 (LCMO), where x = 0.33 or 0.3, to understand the evolution of strain relaxation processes in these materials. The analyses were done using Grazing Incidence X-ray Scattering (GIXS) on films of different thicnesses on two different substrates, (100) oriented LaAlO3 (LAO), with a lattice mismatch of ∼2% and (110) oriented NGO, with a lattice mismatch of less than 0.1%. Films grown on LAO can exhibit up to three in-plane strained lattice constants, corresponding to a slight orthorhombic distortion of the crystal, as well as near-surface and columnar lattice relaxation. As a function of film thickness, a crossover from a strained film to a mixture of strained and relaxed regions in the film occurs in the range of 700 Å. The structural evolution at this thickness coincides with a change in the resistivity curve near the metalinsulator transition. The in-plane compressive strain has a range of 0.2 – 1.5%, depending on the film thickness for filsm in the range of 400 - 1500 A.

Constitutive inequalities for isotropic elastic solids under finite strain

1970 ◽  
Vol 314 (1519) ◽  
pp. 457-472 ◽  
Keyword(s):  
Scalar Product ◽  
Finite Strain ◽  
Strain Analysis ◽  
Stress And Strain ◽  
Elastic Solids ◽  
Intrinsic Interest ◽  
Typical Member ◽  
Rates Of Change ◽  
Constitutive Inequalities ◽  
Strain Measures

Possible restrictions on isotropic constitutive laws for finitely deformed elastic solids are examined from the standpoint of Hill (1968). This introduced the notion of conjugate pairs of stress and strain measures, whereby families of contending inequalities can be generated. A typical member inequality stipulates that the scalar product of the rates of change of certain conjugate variables is positive in all circumstances. Interrelations between the various inequalities are explored, and some statical implications are established. The discussion depends on several ancillary theorems which are apparently new; these have, in addition, an intrinsic interest in the broad field of basic stress—strain analysis.

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