Slope Failure Mechanisms due to Seepage: Three-Dimensional Soil Block Experiments

In this research contribution, the static behavior and failure mechanisms are developed for a three-dimensional (3D) printed dogbone, auxetic structure and sandwich composite using acoustic emissions (AEs). The skins, core and whole sandwich are manufactured using the same bio-based material which is polylactic acid reinforced with micro-flax fibers. Tensile tests are conducted on the skins and the core while bending tests are conducted on the sandwich composite. Those tests are carried out on four different auxetic densities in order to investigate their effect on the mechanical and damage properties of the materials. To monitor the invisible damage and damage propagation, a highly sensitive AE testing method is used. It is found that the sandwich with high core density displays advanced mechanical properties in terms of bending stiffness, shear stiffness, facing bending stress and core shear stress. In addition, the AE data points during testing present an amplitude range of 40–85[Formula: see text]dB that characterizes visible and invisible damage up to failure.

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The Hydromechanical Interplay in the Simplified Three-Dimensional Limit Equilibrium Analyses of Unsaturated Slope Stability

Geosciences ◽

10.3390/geosciences11020073 ◽

2021 ◽

Vol 11 (2) ◽

pp. 73

Author(s):

Panagiotis Sitarenios ◽

Francesca Casini

Keyword(s):

Analytical Solution ◽

Slope Stability ◽

Slope Failure ◽

Failure Modes ◽

Pore Water Pressure ◽

Limit Equilibrium ◽

Water Pressure ◽

Three Dimensional ◽

Stability Limit ◽

Smooth Transition

This paper presents a three-dimensional slope stability limit equilibrium solution for translational planar failure modes. The proposed solution uses Bishop’s average skeleton stress combined with the Mohr–Coulomb failure criterion to describe soil strength evolution under unsaturated conditions while its formulation ensures a natural and smooth transition from the unsaturated to the saturated regime and vice versa. The proposed analytical solution is evaluated by comparing its predictions with the results of the Ruedlingen slope failure experiment. The comparison suggests that, despite its relative simplicity, the analytical solution can capture the experimentally observed behaviour well and highlights the importance of considering lateral resistance together with a realistic interplay between mechanical parameters (cohesion) and hydraulic (pore water pressure) conditions.

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Assessing rockfall susceptibility in steep and overhanging slopes using three-dimensional analysis of failure mechanisms

Landslides ◽

10.1007/s10346-017-0911-y ◽

2017 ◽

Vol 15 (5) ◽

pp. 859-878 ◽

Cited By ~ 14

Author(s):

B. Matasci ◽

G. M. Stock ◽

M. Jaboyedoff ◽

D. Carrea ◽

B. D. Collins ◽

...

Keyword(s):

Dimensional Analysis ◽

Failure Mechanisms ◽

Three Dimensional

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High Cycle Fatigue Resistance and Reliability Assessment of Flexible Printed Circuitry

Journal of Electronic Packaging ◽

10.1115/1.1462628 ◽

2002 ◽

Vol 124 (3) ◽

pp. 254-259 ◽

Cited By ~ 9

Author(s):

Elena Martynenko ◽

Wen Zhou ◽

Alexander Chudnovsky ◽

Ron S. Li ◽

Larry Poglitsch

Keyword(s):

Fatigue Resistance ◽

High Cycle Fatigue ◽

Failure Mechanisms ◽

Three Dimensional ◽

Reliability Assessment ◽

Core Layer ◽

High Strength ◽

Multiple Cracks ◽

Material System ◽

Cycle Fatigue

Flexible printed circuitry (FPC) is a patterned array of conductors supported by a flexible dielectric film made of high strength polymer material such as polyimide. The flexibility of FPC provides an opportunity for three dimensional packaging, easy interconnections and dynamic applications. The polymeric core layer is the primary load bearing structure when the substrate is not supported by a rigid plate. In its composite structure, the conductive layers are more vulnerable to failure due to their lower flexibility compared to the core layer. Fatigue data on FPCs are not commonly available in published literature. Presented in this paper is the fatigue resistance and reliability assessment of polyimide based FPCs. Fatigue resistance of a specific material system was analyzed as a function of temperature and frequency through experiments that utilized a specially designed experimental setup consisting of sine servo controller, electrodynamic shaker, continuity monitor and temperature chamber. The fatigue characteristics of the selected material system are summarized in the form of S-N diagrams. Significant decrease in fatigue lifetime has been observed due to higher displacements in high cycle fatigue. Observed temperature effect was however counter-intuitive. Failure mechanisms are discussed and complete fracture analysis is presented. In various FPC systems, it has been found that the changes take place in FPC failure mechanisms from well-developed and aligned single cracks through the width at low temperature to an array of multiple cracks with random sizes and locations at high temperature.

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