Performance of a New Yielding Rock Bolt Under Pull and Shear Loading Conditions

Three-dimensional planar cracks under mixed-mode loading conditions are investigated by using the selfsimilar crack expansion method with the boundary integral equation technique. For a planar crack under general loading (tensile and shear) conditions, the normal displacement and tangential displacements on the crack surface exhibit uncoupled characteristics. However, the tangential displacements in the two directions are generally coupled. In this paper, two coupled boundary integral equations for a crack subject to shear loading are solved using the analytically numerical method, where the integrals on elements’ are estimated by using the explicit expression of the close form of the integrals. Combination of the self-similar crack expansion method and the analytically numerical method results in good accuracy, with errors in stress intensity factors of penny-shaped cracks and elliptical cracks less than one percent. This numerical analysis is applicable to the analysis of cracks with arbitrary geometry.

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Asymptotic Crack-Tip Fields in Perfectly Plastic Solids Under Mixed Mode II/III Loading Conditions

Journal of Pressure Vessel Technology ◽

10.1115/1.2767355 ◽

2006 ◽

Vol 129 (4) ◽

pp. 664-669

Author(s):

J. Pan ◽

P.-C. Lin

Keyword(s):

Mixed Mode ◽

Crack Tip ◽

Shear Loading ◽

Mode Ii ◽

Pure Mode ◽

Loading Conditions ◽

Mode Iii ◽

Plane Shear ◽

Crack Tip Fields ◽

Perfectly Plastic

In this paper, governing equations and solutions for asymptotic singular and nonsingular crack-tip sectors in perfectly plastic materials are first summarized under combined in-plane and out-of-plane shear loading conditions. The crack-tip fields under mixed mode II/III loading conditions are then investigated. An assembly of crack-tip sectors is adopted with stress discontinuities along the border of the two constant stress sectors. The solutions of the crack-tip fields under pure mode II, mixed mode II/III, and nearly pure mode III loading conditions are presented. The trends of the angular variations of the mixed mode II/III crack-tip stresses agree with those of the available computational analysis and the asymptotic analysis for low strain hardening materials. The pure mode II crack-tip stresses are similar to those of Hutchinson, and the nearly pure mode III stresses are similar to those of the pure mode III crack-tip field of Rice.

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EFFECT OF TENSILE SPEED ON THE FAILURE LOAD OF A SPOT WELD UNDER COMBINED LOADING CONDITIONS

International Journal of Modern Physics B ◽

10.1142/s0217979208046943 ◽

2008 ◽

Vol 22 (09n11) ◽

pp. 1469-1474 ◽

Cited By ~ 6

Author(s):

JUNG-HAN SONG ◽

HOON HUH ◽

JI-HO LIM ◽

SUNG-HO PARK

Keyword(s):

Failure Load ◽

Rate Sensitivity ◽

Shear Loading ◽

Spot Weld ◽

Combined Loading ◽

Failure Behavior ◽

Loading Conditions ◽

Dynamic Failure ◽

Shear Loads ◽

Failure Loads

This paper is concerned with the evaluation of the dynamic failure load of the spot weld under combined axial and shear loading conditions. The testing fixture are designed to impose the combined axial and shear load on the spot weld. Using the proposed testing fixtures and specimens, quasi-static and dynamic failure tests of the spot weld are conducted with seven different combined loading conditions. The failure load and failure behavior of the spot weld are investigated with different loading conditions. Dynamic effects on the failure load of the spot weld, which is critical for structural crashworthiness, are also examined based on the experimental data. In order to evaluate the effect of the strain rate on the failure contour of the spot weld under combined axial and shear loads, the failure loads measured from the experiment are decomposed into the two components along the axial and shear directions. Experimental results indicate that the failure contour is expanded with increasing strain rates according to the rate sensitivity of the ultimate stress for welded material.

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Asymptotic analysis of a crack in a power-law material under combined in-plane and out-of-plane shear loading conditions

Journal of the Mechanics and Physics of Solids ◽

10.1016/0022-5096(90)90031-x ◽

1990 ◽

Vol 38 (2) ◽

pp. 133-159 ◽

Cited By ~ 16

Author(s):

J. Pan

Keyword(s):

Asymptotic Analysis ◽

Power Law ◽

Shear Loading ◽

Loading Conditions ◽

Plane Shear ◽

Out Of Plane

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Peak stresses near narrow rectangular notches, with rounded corners, subjected to tensile and shear loading

The Journal of Strain Analysis for Engineering Design ◽

10.1243/03093247v281005 ◽

1993 ◽

Vol 28 (1) ◽

pp. 5-11 ◽

Cited By ~ 3

Author(s):

T H Hyde ◽

A Yaghi

Keyword(s):

Peak Stress ◽

Shear Loading ◽

Mode I ◽

Mode Ii ◽

Loading Conditions ◽

Notch Width ◽

Corner Radius ◽

Specific Geometry ◽

Stress Concentration Factors ◽

Circular Notch

The finite element method is used to determine the peak stress for narrow rectangular notches, with rounded corners, for a range of notch width to corner radius ratios, under mode I, mode II, and mixed-mode loading conditions. It is shown that the specific geometry and loading conditions are unimportant and that the loading is conveniently characterized by the mode I and mode II stress-intensity factors for an equivalent crack. Superposition of peak stresses for mode I and mode II conditions allows the peak stress in a semi-circular notch to be obtained from simple equations describing the surface tangential stress distributions. A notch shape factor, which dependes only on the notch width to corner radius ratio and mode-mixity parameter, is then used to modify the peak stress values obtained for a semi-circular notch. The method provides a relatively cheap and efficient means of determining stress concentration factors for what can appear to be complex geometries and loading situations.

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Understanding Mechanical Integrity of Metal/Ceramic Interfaces Through In-Situ Micro Mechanical Testing and Multiscale Simulations

Volume 2: Materials; Joint MSEC-NAMRC-Manufacturing USA ◽

10.1115/msec2018-6471 ◽

2018 ◽

Author(s):

Xiaoman Zhang ◽

Yang Mu ◽

Shuai Shao ◽

Collin Wick ◽

Ramu Ramachandran ◽

...

Keyword(s):

Mechanical Testing ◽

Density Functional ◽

Ceramic Coating ◽

Minimum Energy ◽

Shear Loading ◽

Interfacial Region ◽

Loading Conditions ◽

Metal Ceramic ◽

Ceramic Interfaces

Mechanical failures of interfacial regions of ceramic-coating/metal-adhesion-layer/substrate systems were measured quantitatively and observed concurrently through instrumented microscale mechanical testing in-situ a scanning electron microscope (SEM). Failure of the interfacial regions of coating/interlayer/substrate systems was observed in micro-pillar specimens in-situ under different loading conditions, including shear, compression, and tension. Under shear loading, shear failure of the interfacial region was observed to occur in two stages: an initial uniform shear plastic deformation of the entire metal interlayer followed by an unstable shear-off close to the metal/ceramic interface. Additional testing under compression loading conditions suggests that the unstable shear-off is concomitant with the metal/ceramic interface going from being “locked”, with no relative displacement between materials on the two sides of the interface, to being “unlocked”, with significant relative displacements. Failure of the interfacial region was also observed under tensile loading conditions. Density functional theory (DFT) and molecular dynamics (MD) studies on one particular metal/ceramic interface, namely Ti/TiN, showed that a weak interaction plane exists in the metal layer near the chemical interface in a coherent Ti/TiN structure. Consequently, the free energy and theoretical shear strength of the semi-coherent Ti/TiN interface is found to depend on the physical location of the misfit dislocation network (MDN). The minimum energy and strength of the interface occur when the MDN is near, but not at the chemical interface. The present work gives new insight into the nature of mechanical failure of metal/ceramic interfaces, is relevant to materials-based engineering of metal/ceramic interfaces, and has applications to engineering of ceramic coating/substrate systems.

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