scholarly journals Fluid-rich damage zone of an ancient out-of-sequence thrust, Kodiak Islands, Alaska

Tectonics ◽  
2009 ◽  
Vol 28 (1) ◽  
pp. n/a-n/a ◽  
Author(s):  
Christen D. Rowe ◽  
Francesca Meneghini ◽  
J. Casey Moore
Keyword(s):  
Damage Zone ◽  
Kodiak Islands

Deformation Analysis for Coal and Gas Outburst Cavity

2011 ◽  
Vol 121-126 ◽  
pp. 2607-2613
Author(s):  
Qian Ting Hu ◽  
Wen Bin Wu ◽  
Guo Qiang Cheng
Keyword(s):  
Damage Zone ◽  
Coal And Gas Outburst ◽  
Gas Content ◽  
Combination Method ◽  
Deformation Analysis ◽  
Failure Zone ◽  
Finite Element Code ◽  
Cavity Volume ◽  
Gas Emission ◽  
Gas Outburst

Outburst cavity formed during coal and gas outburst can be pear shaped, elliptical, or just like an irregularly elongated ellipsoid, its capacity is always smaller than the volume of ejected coal. And the gas emission quantity is almost 4 to 10 times as gas content in ejected coal. These are two different expressions of the same problem. To find the reasons for the decrease of outburst cavity volume and the increase of gas emission quantity per ton, by using the finite element code ANSYS, the damage zone and the failure zone of the outburst cavity were determined based on the static and dynamic combination method. In this paper, the reason for the decrease of the outburst volume was explained.

scholarly journals Rapid Assessment of Tree Damage Resulting from a 2020 Windstorm in Iowa, USA

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 555
Author(s):  
Thomas C. Goff ◽  
Mark D. Nelson ◽  
Greg C. Liknes ◽  
Tivon E. Feeley ◽  
Scott A. Pugh ◽  
...  
Keyword(s):  
Forest Inventory ◽  
Damage Zone ◽  
Satellite Image ◽  
Rapid Assessment ◽  
Aerial Survey ◽  
Inventory Data ◽  
Tree Damage ◽  
Forest Inventory Data ◽  
Damage Susceptibility ◽  
The Impact

A need to quantify the impact of a particular wind disturbance on forest resources may require rapid yet reliable estimates of damage. We present an approach for combining pre-disturbance forest inventory data with post-disturbance aerial survey data to produce design-based estimates of affected forest area and number and volume of trees damaged or killed. The approach borrows strength from an indirect estimator to adjust estimates from a direct estimator when post-disturbance remeasurement data are unavailable. We demonstrate this approach with an example application from a recent windstorm, known as the 2020 Midwest Derecho, which struck Iowa, USA, and adjacent states on 10–11 August 2020, delivering catastrophic damage to structures, crops, and trees. We estimate that 2.67 million trees and 1.67 million m3 of sound bole volume were damaged or killed on 23 thousand ha of Iowa forest land affected by the 2020 derecho. Damage rates for volume were slightly higher than for number of trees, and damage on live trees due to stem breakage was more prevalent than branch breakage, both likely due to higher damage probability in the dominant canopy of larger trees. The absence of post-storm observations in the damage zone limited direct estimation of storm impacts. Further analysis of forest inventory data will improve understanding of tree damage susceptibility under varying levels of storm severity. We recommend approaches for improving estimates, including increasing spatial or temporal extents of reference data used for indirect estimation, and incorporating ancillary satellite image-based products.

Finite Element Modeling of Damage Formation in Rubber-Toughened Polymer

2005 ◽  
Vol 297-300 ◽  
pp. 1019-1024
Author(s):  
Mitsugu Todo ◽  
Yoshihiro Fukuya ◽  
Seiya Hagihara ◽  
Kazuo Arakawa
Keyword(s):  
Finite Element ◽  
Damage Zone ◽  
Damage Model ◽  
Crack Tip ◽  
Optical Microscope ◽  
Toughening Mechanism ◽  
Element Analysis ◽  
Zone Formation ◽  
Macro Scale ◽  
Rubber Toughened

Microscopic studies on the toughening mechanism of rubber-toughened PMMA (RTPMMA) were carried out using a polarizing optical microscope (POM) and a transmission electron microscope (TEM). POM result showed that in a typical RT-PMMA, a damage zone was developed in the vicinity of crack-tip, and therefore, it was considered that energy dissipation due to the damage zone development was the primary toughening mechanism. TEM result exhibited that the damage zone was a crowd of micro-crazes generated around rubber particles in the vicinity of notch-tip. Finite element analysis was then performed to simulate such damage formations in crack-tip region. Macro-scale and micro-scale models were developed to simulate damage zone formation and micro-crazing, respectively, with use of a damage model. It was shown that the damage model introduced was successfully applied to predict such kind of macro-damage and micro-craze formations.

Numerical Simulation of Blasting-Induced Damage in Grouting Curtain of Sandstone Aquifer for Vertical Shaft

2015 ◽  
Vol 723 ◽  
pp. 271-278
Author(s):  
Yu Liang Zhou ◽  
Dong Feng Yuan ◽  
Jun Zheng ◽  
Hua Wang
Keyword(s):  
Numerical Simulation ◽  
Prevention And Control ◽  
Damage Zone ◽  
Surrounding Rock ◽  
Damage Effect ◽  
Vertical Shaft ◽  
Control Methods ◽  
Sandstone Aquifer ◽  
And Control ◽  
Dynamic Damage

To provide a theoretical basis for water prevention and control methods and reasonable supporting techniques for vertical shaft, and to ensure the shaft construction to pass the sandstone aquifer safely and rapidly, numerical simulation using dynamic damage constitutive model, which was a user-defined constitutive modules in FLAC3D, a lagrangian analysis code in three dimensions, has been applied to investigate the dynamic damage effect in the surrounding rock of the grouting curtain near the driving working face for vertical shaft excavated by blasting. The results indicate that the distribution of the damage zone in the surrounding rock of the shaft, which decreases the effective thickness of the grouting curtain, was like a ellip-se, and that the depth of the damage zone in the surrounding rock of the shaft grouting curtain is fewer than that of the driving face floor. It can be concluded that the centre part of the driving face floor, especially the cutting hole zones, and the shaft wall in the greater horizontal stress side are the " key parts " for shaft water prevention and control methods.

Research on Automatic Detection Technology for Coal Seam Floor Failure Features

2011 ◽  
Vol 467-469 ◽  
pp. 1870-1875 ◽  
Author(s):  
Guang Ming Zhao ◽  
Xiang Rui Meng
Keyword(s):  
Coal Seam ◽  
Water Inrush ◽  
Damage Zone ◽  
Detection Technology ◽  
Floor Failure ◽  
Industry Practice ◽  
Iteration Model ◽  
Forward Calculation ◽  
Mining Coal ◽  
The Impact

By the impact of coal mining, coal floor will produce distortion and damage, and make the damage zone which may result in water inrush from the floor of coal seam. CT technology with DC electricity is used to analyze two-dimensional point source current field by employing the forward calculation, inverse iteration, model correction and other methods. On the basis, inverted resistivity image of the detecting zone is obtained, which can help to determine damage law and damage depth of coal seam floor. And then the possibility of water inrush from the coal floor is analyzed. Industry practice shows that the research results are credible and can play an important guiding role in the controlling of water inrush.

scholarly journals Integrated petrographic – rock mechanic borecore study from the metamorphic basement of the Pannonian Basin, Hungary

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
László Molnár ◽  
Balázs Vásárhelyi ◽  
Tivadar M. Tóth ◽  
Félix Schubert
Keyword(s):  
Compressive Strength ◽  
Fault Zone ◽  
Uniaxial Compressive Strength ◽  
Pannonian Basin ◽  
Damage Zone ◽  
Rock Mechanic ◽  
Fault Rock ◽  
Hydrocarbon Reservoir ◽  
Migration Pathway ◽  
Metamorphic Basement

AbstractThe integrated evaluation of borecores from the Mezősas-Furta fractured metamorphic hydrocarbon reservoir suggests significantly distinct microstructural and rock mechanical features within the analysed fault rock samples. The statistical evaluation of the clast geometries revealed the dominantly cataclastic nature of the samples. Damage zone of the fault can be characterised by an extremely brittle nature and low uniaxial compressive strength, coupled with a predominately coarse fault breccia composition. In contrast, the microstructural manner of the increasing deformation coupled with higher uniaxial compressive strength, strain-hardening nature and low brittleness indicate a transitional interval between the weakly fragmented damage zone and strongly grinded fault core. Moreover, these attributes suggest this unit is mechanically the strongest part of the fault zone. Gougerich cataclasites mark the core zone of the fault, with their widespread plastic nature and locally pseudo-ductile microstructure. Strain localization tends to be strongly linked with the existence of fault gouge ribbons. The fault zone with ∼15 m total thickness can be defined as a significant migration pathway inside the fractured crystalline reservoir. Moreover, as a consequence of the distributed nature of the fault core, it may possibly have a key role in compartmentalisation of the local hydraulic system.

Failure load prediction of laminates repaired with a scarf-bonded patch using the damage zone method

2016 ◽  
Vol 26 (2) ◽  
pp. 115-133 ◽  
Author(s):  
Viet-Hoai Truong ◽  
Jae-Seung Yoo ◽  
Choong-Hyun Kim ◽  
Min-Young Park ◽  
Jin-Ho Choi ◽  
...  
Keyword(s):  
Failure Load ◽  
Damage Zone ◽  
Load Prediction ◽  
Zone Method
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