Prediction of Failure Conditions

Abstract Purpose In this study, the robustness and feasibility of a noise elimination method using continuous wave response of therapeutic ultrasound signals were investigated when tissue samples were moved to simulate the respiration-induced movements of the different organs during actual high-intensity focused ultrasound (HIFU) treatment. In addition to that, the failure conditions of the proposed algorithm were also investigated. Methods The proposed method was applied to cases where tissue samples were moved along both the lateral and axial directions of the HIFU transducer to simulate respiration-induced motions during HIFU treatment, and the noise reduction level was investigated. In this experiment, the speed of movement was increased from 10 to 40 mm/s to simulate the actual movement of the tissue during HIFU exposure, with the intensity and driving frequency of HIFU set to 1.0–5.0 kW/cm2 and 1.67 MHz, respectively. To investigate the failure conditions of the proposed algorithm, the proposed method was applied with the HIFU focus located at the boundary between the phantom and water to easily cause cavitation bubbles. The intensity of HIFU was set to 10 kW/cm2. Results Almost all HIFU noise was constantly able to be eliminated using the proposed method when the phantom was moved along the lateral and axial directions during HIFU exposure. The noise reduction level (PRL in this study) at an intensity of 1.0, 3.0, and 5.0 kW/cm2 was in the range of 28–32, 38–40, and 42–45 dB, respectively. On the other hand, HIFU noise was not basically eliminated during HIFU exposure after applying the proposed method in the case of cavitation generation at the HIFU focus. Conclusions The proposed method can be applicable even if homogeneous tissues or organs move axially or laterally to the direction of HIFU exposure because of breathing. A condition under which the proposed algorithm failed was when instantaneous tissue changes such as cavitation bubble generation occurred in the tissue, at which time the reflected continuous wave response became less steady.

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Failure Conditions of the Annular Gaskets of Flange Joints

Chemical and Petroleum Engineering ◽

10.1007/s10556-014-9802-4 ◽

2014 ◽

Vol 49 (9-10) ◽

pp. 600-605

Author(s):

V. D. Prodan ◽

G. V. Bozhko ◽

P. N. Boiko

Keyword(s):

Failure Conditions

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Assessment of instability initiation in exposed salt rock roofs

Gornyi Zhurnal ◽

10.17580/gzh.2021.04.04 ◽

2021 ◽

pp. 34-38

Author(s):

D. N. Shkuratskiy ◽

D. S. Chernopazov ◽

I. B. Vaulina

Keyword(s):

Damage Zone ◽

Shear Plane ◽

Plane Elasticity ◽

Mining Operations ◽

Support Design ◽

Salt Rocks ◽

Main Requirement ◽

Potash Salt ◽

Failure Conditions ◽

Coulomb Criterion

Stability of rocks is the main requirement for the safe operation of mines. For this purpose, certain measures are applied for the protection and support of underground openings, including roof support design and roof arrangement in the most stable rocks. Stability assessment of underground excavations is largely related to their roof stability. Determination of possible instability conditions in mine roofs governs the choice of support system design and parameters of mine excavations. The Upper Kama Potash Salt Deposit represents a stratified layer of solid salt rocks. Roof instability develops as stratification and roof collapse. The Mohr–Coulomb criterion of coherent rocks is currently used to estimate parameters of a possible damage zone in the exposed roof. This criterion allows evaluating shear plane angles in roof rocks and, as a result, finding parameters of the possible collapse zone. The experience of mining operations in the Upper Kama deposit shows different failure conditions as against the Mohr–Coulomb criterion as the stress state is scarcely included in the criterion used. This study is an attempt to assess parameters of rock exposures by solving a Lame problem in terms of a single mine excavation. The analytical results were compared with the parameters obtained from the plane elasticity solutions by the finite element method. Based on the implemented studies, an engineering approach is developed for the assessment of anticipated instability parameters in exposed roofs in horizontal excavations driven in salt rocks.

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Dynamic Responses of Spar Type Floating Offshore Wind Turbine Under Mooring Failure Conditions

10.1115/1.0000739v ◽

2021 ◽

Author(s):

YAJUN REN ◽

Vengatesan Venugopal

Keyword(s):

Wind Turbine ◽

Dynamic Responses ◽

Offshore Wind ◽

Offshore Wind Turbine ◽

Floating Offshore Wind Turbine ◽

Failure Conditions

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A numerical approach to predict soil bearing potential for isolated footing

10.5194/egusphere-egu21-321 ◽

2021 ◽

Author(s):

Gilbert Hinge ◽

Jayanta Kumar Das ◽

Biswadeep Bharali

Keyword(s):

Bearing Capacity ◽

Shear Failure ◽

Correlation Coefficients ◽

Failure Criteria ◽

Numerical Approach ◽

Ultimate Bearing Capacity ◽

Foundation Design ◽

Advantages And Disadvantages ◽

Local Shear ◽

Failure Conditions

<p>The success of any civil engineering structure's foundation design depends upon the accuracy of estimation of soil&#8217;s ultimate bearing capacity. Numerous numerical approaches have been proposed to estimate the foundation's bearing capacity value to avoid repetitive and expensive experimental work. All these models have their advantages and disadvantages. In this study, we compiled all the governing equations mentioned in Bureau of Indian standard IS:6403-1981 and modify the equation for Ultimate Bearing Capacity. The equation was modified by considering two new parameters, K1(for general shear) and K2 (for local shear) so that a common governing equation can be used for both general and local shear failure criteria. The program used for running the model was written in MATLAB language code and verified with the observed field data. Results indicate that the proposed model accurately characterized the ultimate, safe, and allowable bearing capacity of a shallow footing at different depths. The correlation coefficients between the observed and model-predicted bearing capacity values for a 2m foundation depth with footing size of 1.5 &#215;1.5, 2.0 &#215; 2.0, and 2.5 &#215; 2.5 m are 0.95, 0.94, and 0.96. A similar result was noted for the other foundation depth and footing size. Findings show that the model can be used as a reliable tool for predicting the bearing capacity of shallow foundations at any given depth. &#160;Moreover, the formulated model can also be used for the transition zone between general and local shear failure conditions.</p>

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The SMART SRP Well – Application of Edge Analytics for Automated Well Performance Control and Condition Monitoring in a Mature Brownfield Environment – A Case Study from Austria

10.2118/208521-ms ◽

2021 ◽

Author(s):

Christian Windisch

Keyword(s):

Condition Monitoring ◽

Data Communication ◽

Holistic Approach ◽

Well Performance ◽

Measuring Device ◽

Technology Transfers ◽

Failure Conditions ◽

Diverse Data ◽

Bottomhole Pressure

Abstract This paper presents a holistic approach to modern oilfield and well surveillance through the inclusion of state-of-the-art edge computing applications in combination with a novel type of data transmission technology and algorithms developed in-house for automatic condition monitoring of SRP systems. The objective is to enable the responsible specialist staff to focus on the most important decisions regarding oilfield management, rather than wasting time with data collection and preparation. An own operated data communication system, based on LPWAN-technology transfers the dyno-cards, generated by an electric load cell, into the in-house developed production assistance software platform. Suitable programmed AI-algorithms enable automatic condition detection of the incoming dyno cards, including conversion and analysis of the corresponding subsurface dynamograms. A smart alarming system informs about occurring failure conditions and specifies whether an incident of rod rupture, pump-off condition, gas lock or paraffin precipitation occurred in the well. A surface mounted measuring device delivers liquid level and bottomhole pressure information automatically into the software. Based on these diverse data, the operations team plans the subsequent activities. The holistic application approach is illustrated using the case study of an SPR-operated well in an Austrian brownfield.

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