Effect of Fluke Inclination on Behavior of Drag Anchor in Uniform Clay Under Unidirectional and Combined Loading

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Xiaoni Wu ◽  
Yean Khow Chow ◽  
Chun Fai Leung
Keyword(s):  
Inclination Angle ◽  
Promising Method ◽  
Combined Loading ◽  
Embedment Depth ◽  
Practical Case ◽  
Depth Ratio ◽  
Envelope Method ◽  
Inclination Angles ◽  
Selection Of ◽  
Shape And Size

Prediction of trajectory of drag anchor is important for the design and selection of drag anchor. Prediction based on yield envelope characterizing the anchor behavior under combined loading provides a promising method. However, the existing application of the yield envelope method ignores the effect of the fluke inclination angle by assuming a horizontally placed anchor fluke. This study aims to investigate the behavior of inclined fluke, which is the practical case during installation. The effects of the fluke inclination angle and embedment depth ratio on the anchor behavior in uniform clay under unidirectional loading and combined loading are investigated. It is found that the effect of the fluke inclination angle on the unidirectional capacity factors is mainly for anchor with embedment depth ratio less than 3. This results in the large difference of the size of the yield envelopes for fluke with same smaller embedment depth ratio but different fluke inclination angle, while the effect is minor on the shape of the yield envelope for such cases. However, there is large difference in the shape and size of the shallow yield envelopes for fluke with different embedment depth ratios and inclination angles.

scholarly journals Acoustic Emission Characteristics and Joint Nonlinear Mechanical Response of Rock Masses under Uniaxial Compression

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 200
Author(s):  
Zhongliang Feng ◽  
Xin Chen ◽  
Yu Fu ◽  
Shaoshuai Qing ◽  
Tongguan Xie
Keyword(s):  
Acoustic Emission ◽  
Uniaxial Compression ◽  
Inclination Angle ◽  
Failure Modes ◽  
Strain Curve ◽  
Particle Flow Code ◽  
Rock Masses ◽  
Physical Experiments ◽  
Inclination Angles ◽  
Joint Inclination

The joint arrangement in rock masses is the critical factor controlling the stability of rock structures in underground geotechnical engineering. In this study, the influence of the joint inclination angle on the mechanical behavior of jointed rock masses under uniaxial compression was investigated. Physical model laboratory experiments were conducted on jointed specimens with a single pre-existing flaw inclined at 0°, 30°, 45°, 60°, and 90° and on intact specimens. The acoustic emission (AE) signals were monitored during the loading process, which revealed that there is a correlation between the AE characteristics and the failure modes of the jointed specimens with different inclination angles. In addition, particle flow code (PFC) modeling was carried out to reproduce the phenomena observed in the physical experiments. According to the numerical results, the AE phenomenon was basically the same as that observed in the physical experiments. The response of the pre-existing joint mainly involved three stages: (I) the closing of the joint; (II) the strength mobilization of the joint; and (III) the reopening of the joint. Moreover, the response of the pre-existing joint was closely related to the joint’s inclination. As the joint inclination angle increased, the strength mobilization stage of the joint gradually shifted from the pre-peak stage of the stress–strain curve to the post-peak stage. In addition, the instantaneous drop in the average joint system aperture (aave) in the specimens with medium and high inclination angles corresponded to a rapid increase in the form of the pulse of the AE activity during the strength mobilization stage.

The envelope method in the problem of choosing a rational composition of measuring instruments

2021 ◽  
pp. 68-72
Author(s):  
Il'ya A. Meshchikhin ◽  
Sergej S. Gavryushin
Keyword(s):  
Mathematical Model ◽  
Monitoring Systems ◽  
Measuring Instruments ◽  
Key Points ◽  
Envelope Method ◽  
Loaded State ◽  
The Mathematical Model ◽  
Selection Of ◽  
Rational Composition

As part of the development of monitoring systems for the operation of technical objects, the problem of improving the quality of monitoring systems for the loaded state is considered. Based on the analysis of the mathematical model of the structure and its loading, a methodology for the selection of measuring instruments was developed. The urgency of the problem of calculating substantiation of the choice of key points of the structure is shown, at which it is possible to measure deformations for the subsequent restoration of the existing loads with maximum accuracy. An approach based on the envelope method for determining the rational composition of measuring instruments for restoring the loads acting on the structure is stated.

Aerodynamic effects of bio-inspired corrugated wings on gliding and hovering performances

2020 ◽  
pp. 095440622091799
Author(s):  
Haibin Xuan ◽  
Jun Hu ◽  
Yong Yu ◽  
Jiaolong Zhang
Keyword(s):  
Inclination Angle ◽  
Fluid Dynamic ◽  
Angle Of Attack ◽  
Aerodynamic Forces ◽  
Limited Effect ◽  
Gliding Flight ◽  
Significant Difference ◽  
Inclination Angles ◽  
Underlying Mechanisms ◽  
Lift And Drag

Recently, numerous studies have been conducted to clarify the effects of corrugation wing on aerodynamic performances. The effects of the corrugation patterns and inclination angles were investigated using computational fluid dynamic method in gliding and hovering flight at Reynolds numbers of order 104. The instantaneous aerodynamic forces and the vorticity field around the wing models were provided to research the underlying mechanisms of aerodynamic effects of corrugated wing models. The findings can be concluded as follows: (1) the corrugation patterns have different effects on aerodynamic performance. The effect of noncamber corrugated wing is to decrease the lift and increase drag compared with a flat-plate when the angle of attack is less than 25° during gliding flight. The corrugated wing with a camber (corrug-2) after the valleys enhances the aerodynamic forces when angle of attack is higher than 35°. The valley inclination angle has limited effect on aerodynamic forces in gliding flight. (2) The lift forces of different corrugation patterns show significantly asymmetric during the upstroke and downstroke. The main reason leads to this phenomenon is the case that two sides of the corrugated wings are not symmetric around the pitching axis. The corrugated wing with only two valleys (corrug-1) changes the lift and drag very slightly. Corrug-2 produces larger peak during downstroke and smaller peak during upstroke. The increase in the inclination angle has limited effect on the aerodynamic forces. The possible reason for these small aerodynamic effects might be that the corrugated wings are smoothed by small vortices trapped in valleys. The main reason for the significant difference between plate and corrug-2 is that the recirculating vortices trapped in the saddle and hump reduce the pressure above the wing surface.

scholarly journals Bayesian hierarchical inference of asteroseismic inclination angles

2019 ◽  
Vol 488 (1) ◽  
pp. 572-589 ◽  
Author(s):  
James S Kuszlewicz ◽  
William J Chaplin ◽  
Thomas S H North ◽  
Will M Farr ◽  
Keaton J Bell ◽  
...  
Keyword(s):  
Inclination Angle ◽  
Angle Distribution ◽  
Data Set ◽  
Single Star ◽  
Bayesian Hierarchical ◽  
Hierarchical Method ◽  
Giant Stars ◽  
Inclination Angles ◽  
Red Giant Stars ◽  
Red Giant

Abstract The stellar inclination angle – the angle between the rotation axis of a star and our line of sight – provides valuable information in many different areas, from the characterization of the geometry of exoplanetary and eclipsing binary systems to the formation and evolution of those systems. We propose a method based on asteroseismology and a Bayesian hierarchical scheme for extracting the inclination angle of a single star. This hierarchical method therefore provides a means to both accurately and robustly extract inclination angles from red giant stars. We successfully apply this technique to an artificial data set with an underlying isotropic inclination angle distribution to verify the method. We also apply this technique to 123 red giant stars observed with Kepler. We also show the need for a selection function to account for possible population-level biases, which are not present in individual star-by-star cases, in order to extend the hierarchical method towards inferring underlying population inclination angle distributions.

scholarly journals An experimental study on the effect of tool geometry on tool wear and surface roughness in hard turning

2020 ◽  
Vol 12 (9) ◽  
pp. 168781402095988
Author(s):  
Pham Minh Duc ◽  
Le Hieu Giang ◽  
Mai Duc Dai ◽  
Do Tien Sy
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Inclination Angle ◽  
Hard Turning ◽  
Rake Angle ◽  
Machining Process ◽  
Tool Geometry ◽  
Standard Tool ◽  
Inclination Angles ◽  
Mixed Ceramic

The main purpose of this study is to investigate the influence of tool geometry (cutting edge angle, rake angle, and inclination angle) and to optimize tool wear and surface roughness in hard turning of AISI 1055 (52HRC) hardened steel by using TiN coated mixed ceramic inserts. The results show that the inclination angle is the major factor affecting the tool wear and the surface roughness in hard turning. With the increase in negative rake and inclination angles, the tool wear decreases, and the surface roughness increases. However, the surface roughness will decrease when the inclination angle increases to overpass a certain limit. This is a new and significant point in the research of the hard turning process. From this result, the large negative inclination angle (λ = −10°) should be applied to reduce the surface roughness and the tool wear simultaneously. With the optimal cutting tool angles in the research, the hard machining process is improved remarkably with decreases of surface roughness and tool wear 8.3% and 41.3%, respectively in comparison with the standard tool angles. And the proposed tool-post design approach brings an effective method to change the tool insert angles using standard tool-holders to improve hard or other difficult-to-cut materials turning quality.

Case Studies on ECA-Based Flaw Acceptance Criteria for Pipe Girth Welds Using BS 7910:2005

2007 ◽  
Author(s):  
Mohamad J. Cheaitani
Keyword(s):  
Case Studies ◽  
Pipe Wall ◽  
Single Point ◽  
Welding Residual Stress ◽  
Practical Case ◽  
Acceptance Criteria ◽  
Specific Level ◽  
Failure Assessment ◽  
Girth Welds ◽  
Selection Of

The use of an engineering critical assessment (ECA) approach to derive flaw acceptance criteria for pipe girth welds has become common practice. It allows the maximum tolerable size of weld flaws to be determined on a fitness-for-purpose basis, offering substantial advantages over the conventional workmanship approach. BS 7910:2005 is widely used to derive ECA-based flaw acceptance criteria for pipe girth welds. It offers a flexible assessment framework within the context of the well-established failure assessment diagram (FAD) approach. However, it can be relatively complex to apply and it may lead to assessments that are more conservative than codified pipeline-specific procedures. This paper illustrates, through practical case studies on assessing the significance of circumferential girth weld flaws, some of the options available to the user of BS 7910. The case studies cover the selection of the FAD (generalised or material-specific, with and without yield discontinuity), tensile properties (specified minimum or actual values); fracture toughness properties (single point CTOD values including δ0.2BL and δm, or full CTOD resistance R-curve), and welding residual stress (assumed to be uniform through the pipe wall with a yield strength magnitude, or considered to have a through-wall distribution associated with a specific level of welding heat input).

A Numerical Study on the Effect of Hole Inclination Angle With Imperfection on Film Cooling Effectiveness

2019 ◽  
Author(s):  
Taha Rezzag ◽  
Bassam A. Jubran
Keyword(s):  
Inclination Angle ◽  
Film Cooling ◽  
Numerical Study ◽  
Vortex Pair ◽  
Dimensionless Temperature ◽  
Film Cooling Effectiveness ◽  
Blowing Ratio ◽  
Laser Percussion Drilling ◽  
Inclination Angles ◽  
Lift Off

Abstract The present study numerically evaluates the influence of hole inclination angle with a hole imperfection on film cooling performance. Here, the hole imperfection due to laser percussion drilling is modelled as a half torus. Three hole inclination angles were investigated: 35°, 45° and 55°. Furthermore, every case was evaluated at three blowing ratios: 0.45, 0.90 and 1.25. Each case is compared to a baseline case where the hole imperfection is absent. The results indicate that the hole inclination angle has a strong influence on the film effectiveness performance when a hole imperfection is present. Centerline effectiveness plots reveal a maximum effectiveness deterioration of 89% for a blowing ratio of 0.90 in the vicinity of the hole exit. Dimensionless temperature contours show that the jet produced in the presence of an imperfection is much more compact causing the counter rotating vortex pair to be closer to each other. This enhances the jet to lift off from the plate.

The Experimental Study of Single Droplet Impinging on an Inclined Heated Wall

2020 ◽  
Author(s):  
Wenlong Tian ◽  
Huang Zhang ◽  
Qianfeng Liu ◽  
Guang Hu ◽  
Wen He
Keyword(s):  
Inclination Angle ◽  
Wall Temperature ◽  
Weber Number ◽  
High Speed ◽  
Conservation Equation ◽  
Heated Wall ◽  
Single Droplet ◽  
Droplet Spreading ◽  
Energy Conservation Equation ◽  
Inclination Angles

Abstract We investigated a single droplet impinging on an inclined heated wall with different inclination angles. A high-speed camera was used to observe this impinging process at 10000 frames / second. The phenomena of the droplet spreading, shrinking, rebounding, boiling, break-up and splashing were observed. The effects of the wall temperature (Tw, 40–262 °C), the Weber number of the droplet (Wed, 0.66–589) and the wall inclination angle (α, 0–45.6°) on the spreading behavior of the droplet after impinging on the wall were analyzed. Energy conservation equation was used to analyze experimental results. The results show that increasing the inclination angle of the wall is beneficial to the forward spreading of the droplet along the wall, but not to the downward spreading. When α > 45.6°, the droplet will break through the flow resistance of the wall and slide down all the time. The increase of the wall temperature and the Weber number of the droplet is beneficial to the backward and forward spreading of the droplet. Increasing α, increasing Tw and decreasing Wed will promote the shrinking of the droplet after spreading. In addition, the experimental phenomenon also shows that the larger the wall inclination and the higher the wall temperature, the easier the droplet will break away from the wall.

The Onset of Gas Entrainment From a Stratified Two-Phase Region Through a Single Side-Oriented Branch

2002 ◽  
Author(s):  
M. Ahmed ◽  
K. Lenard ◽  
I. Hassan ◽  
N. Esmail
Keyword(s):  
Inclination Angle ◽  
Density Ratio ◽  
Phase Region ◽  
Data Sets ◽  
Critical Height ◽  
Two Phase ◽  
Gas Entrainment ◽  
Single Side ◽  
Inclination Angles ◽  
Predicted Values

A new theoretical investigation has been conducted for the prediction of the critical height at the onset of gas entrainment during single discharge from a stratified two-phase region through a branch installed on an inclined flat wall. Two models have been developed; a simplified point-sink model and a more-accurate finite-branch. The predicted critical height at the onset of gas entrainment was proven to be a function of Froude number (Fr) and density ratio of the interface fluids. The results of the predicted critical height at the onset of gas entrainment, at low values of Fr (<10), were found to be more accurate when using the finite-branch analysis compared to the results found using the pink-sink analysis. Whereas, with increasing Fr, the predicted values of both models converged to the same value. Furthermore, the point-sink analysis was demonstrated to be independent of wall inclination angle, while the finite-branch analysis showed a slight decrease in the value of the critical height with increasing wall inclination angle. Three different experimental data sets at wall inclination angles of zero, 45 and 90 degrees (i.e. side, inclined and bottom branches) were used in the following study for the comparisons between the experimental and theoretically predicted results. A good concurrence was illustrated between the experimental and theoretical values.

TISM for analysis of barriers affecting the adoption of lean concepts to electronics component manufacture

2020 ◽  
Vol 11 (6) ◽  
pp. 1141-1173
Author(s):  
Senthil Kumar D. ◽  
S. Vinodh
Keyword(s):  
Structural Model ◽  
Matrix Multiplication ◽  
Change Agents ◽  
Practical Case ◽  
Interpretive Structural Modeling ◽  
Content Type ◽  
Management Commitment ◽  
Top Management Commitment ◽  
Component Manufacturing ◽  
Selection Of

Purpose The purpose of this paper is to present the analysis of barriers affecting the adoption of lean concepts to electrical and electronics component manufacturing. Design/methodology/approach Lean concepts are being increasingly applied by electrical and electronics component manufacturers to enhance product value through streamlined process. To facilitate smooth adoption of lean concepts, barriers need to be analyzed and prioritized. In this context, a structural model of 24 barriers is developed through total interpretive structural modeling (TISM) approach. Findings ‘Changing governmental policies,’ ‘poor selection of change agents and improvement teams,’ ‘lack of top management commitment understanding and support of the system,’ ‘lack of team autonomy,’ ‘lack of flexibility and versatility’ and ‘lack of customer focus/involvement’ are found to be the dominant barriers based on TISM study. Interpretation statements are being derived from TISM model. Cross-impact matrix multiplication applied to classification analysis is conducted. Research limitations/implications In the present paper, 24 barriers are considered. In future, additional barriers could be considered to deal with managerial advancements. Practical implications The paper reports the practical case of analysis of barriers to lean adoption in electronics component manufacture. Hence, the inferences have practical relevance. Originality/value The development of structural model for the analysis of barriers to lean implementation in electronics component manufacturing small- and medium-sized enterprises is the original contribution of the authors.

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