Stress Fields At The Central Point Of Arc Crack Under Uniaxial Tension

2019 ◽  
Vol 10 (9) ◽  
pp. 671-674
Author(s):  
M. M. Aish
Keyword(s):  
Uniaxial Tension ◽  
Central Point ◽  
Stress Fields ◽  
Arc Crack

Stress Concentration Factors From Overlapping Stress Fields in Uniaxial Tension

1976 ◽  
Vol 98 (1) ◽  
pp. 332-339 ◽  
Author(s):  
H. T. Gencsoy ◽  
J. F. Hamilton ◽  
C. C. Yang
Keyword(s):  
Stress Concentration ◽  
Uniaxial Tension ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Substantial Effect ◽  
Stress Fields ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Stress Raisers ◽  
Resultant Stress

Standard transmission photoelastic techniques were used to determine the resultant stress concentration factors produced by multiple stress raisers in flat, rectangular bars under uniaxial tension. Observations were made on the overlapping stress fields due to various combinations and orientations of holes and semicircular grooves. Two cases of directly superposed discontinuities were also investigated. The results of this investigation indicate that the sizes and relative positions of the discontinuities had a substantial effect on the resultant stress concentration factor. In some cases the stress concentration factor would be decreased while in other cases it would be increased. In the case of superposed stress raisers considered in this investigation, the resultant stress concentration factor can be taken as the product of the individual stress concentration factors; this is in agreement with the results of other investigators. However, for other cases, much judgment and experience will be required to decide when this can be done. And even then this product should be considered only as the probable upper limit of the actual stress concentration factor.

Intensity of Singular Stress Fields at the End of a Cylindrical Inclusion

2003 ◽  
Vol 70 (4) ◽  
pp. 487-495 ◽  
Author(s):  
N.-A. Noda ◽  
T. Genkai ◽  
Q. Wang
Keyword(s):  
Stress Intensity ◽  
Uniaxial Tension ◽  
Stress Intensity Factors ◽  
Body Force ◽  
Cylindrical Inclusion ◽  
Stress Fields ◽  
Density Functions ◽  
Intensity Factors ◽  
Singular Stress ◽  
Singular Stress Fields

In short fiber reinforced composite it is known that the singular stress at the end of fibers causes crack initiation, propagation, and final failure. The singular stress field is controlled by the generalized stress intensity factors defined at the end of the inclusion. In this study the stress intensity factors are discussed for an elastic cylindrical inclusion in an infinite body under (A) asymmetric uniaxial tension in the x direction, and (B) symmetric uniaxial tension in the z direction. These problems are formulated as a system of integral equations with Cauchy-type or logarithmic-type singularities, where densities of body force distributed in infinite bodies having the same elastic constants as those of the matrix and inclusion are unknown. In the numerical analysis, the unknown body force densities are expressed as fundamental density functions and weight functions. Here, fundamental density functions are chosen to express the symmetric and skew-symmetric stress singularities. Then, the singular stress fields at the end of a cylindrical inclusion are discussed with varying the fiber length and elastic ratio. The results are compared with the ones of a rectangular inclusion under longitudinal and transverse tension.

scholarly journals Tectonophysical criteria for forecasting the locations of quartz crystal deposits (case of Subpolar Ural)

2020 ◽  
Vol 11 (1) ◽  
pp. 31-38
Author(s):  
L. A. Sim
Keyword(s):  
Stress State ◽  
Stress Field ◽  
Uniaxial Tension ◽  
Quartz Crystal ◽  
Stress Fields ◽  
Mineral Deposits ◽  
Tectonic Stresses ◽  
Quartz Veins ◽  
General Stress ◽  
Type Of Stress State

Spatial reconstruction of tectonic stresses within the Subpolar Ural quartz crystal-containing province was conducted by the kinematic method [Gushchenko, 1973, 1979] based on the main indicators of tectonic stresses on slickensides. Local stress states (LSS) and general stress fields for large blocks were reconstructed by the method described in [Sim, Marinin, 2015]. In the blocks with numerous occurrences of quartz crystal (Pelingichey and Omega-Shor blocks), the general stress fields is characterized by a stress state close to uniaxial tension, i.e. the Lode-Nadai coefficient µ=–1. In these blocks, thick quartz veins are perpendicular to the tension axis of the general stress field. In the block without quartz crystal (West Saled), the general stress field is characterized by a triaxial stress state or pure shear state (–1˂µσ˂+1). The LSS of the quartz crystal deposits show the following: the stress state of µ=–1 is typical of quartz veins without quartz crystal nests, and a special kind of stress state is reconstructed near the nests with piezoelectric material. It is named a variation of the type of stress state (VTSS), which means that within one tectonic stage, the type of stress state changes approximately as follows: µσ=+1 (40 %), µσ=–1 (40 %), and –1˂µσ˂+1. It means that in the piezoelectric mineral deposits, pulsating tectonic stresses provided for a fluid flow of hydrothermal solutions at the intersection of ore-bearing and ore-controling faults when tension (µ=–1) was replaced with compression (µ=+1), while the orientations of compression and tension axes remained unchanged. Apparently, such a regime was caused by alternating activation of the above-mentioned faults. The tectonic stress reconstructions were performed for 33 mineral deposits and occur­rences of quartz crystal. VTSS was determined in 32 deposits; one mineral occurrence is characterized by uniaxial tension. Therefore, we propose using VTSS (variation of the type of stress state) as a criterion for predicting the locations of quartz crystal deposits.

Relationships between hierarchical structure and properties in macromolecular systems

1987 ◽  
Vol 45 ◽  
pp. 440-443
Author(s):  
E. Baer
Keyword(s):  
Uniaxial Tension ◽  
Hierarchical Structure ◽  
Inorganic Material ◽  
Hierarchical Structures ◽  
Bone Collagen ◽  
Structure And Properties ◽  
Connective Tissues ◽  
Scale Level ◽  
Fibrous Protein ◽  
Macromolecular Systems

The most advanced macromolecular materials are found in plants and animals, and certainly the connective tissues in mammals are amongst the most advanced macromolecular composites known to mankind. The efficient use of collagen, a fibrous protein, in the design of both soft and hard connective tissues is worthy of comment. Very crudely, in bone collagen serves as a highly efficient binder for the inorganic hydroxyappatite which stiffens the structure. The interactions between the organic fiber of collagen and the inorganic material seem to occur at the nano (scale) level of organization. Epitatic crystallization of the inorganic phase on the fibers has been reported to give a highly anisotropic, stress responsive, structure. Soft connective tissues also have sophisticated oriented hierarchical structures. The collagen fibers are “glued” together by a highly hydrated gel-like proteoglycan matrix. One of the simplest structures of this type is tendon which functions primarily in uniaxial tension as a reinforced elastomeric cable between muscle and bone.

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