scholarly journals Computational simulations of the helical buckling behavior of blood vessels

2019 ◽  
Vol 35 (12) ◽  
Author(s):  
Mohammadali Sharzehee ◽  
Fatemeh Fatemifar ◽  
Hai‐Chao Han
Keyword(s):  
Blood Vessels ◽  
Computational Simulations ◽  
Buckling Behavior ◽  
Helical Buckling

Effects of Friction on Post-Buckling Behavior and Axial Load Transfer in a Horizontal Well

SPE Journal ◽  
2010 ◽  
Vol 15 (04) ◽  
pp. 1104-1118 ◽  
Author(s):  
Guohua Gao ◽  
Stefan Miska
Keyword(s):  
Boundary Conditions ◽  
Critical Load ◽  
Axial Load ◽  
Load Transfer ◽  
Experimental Studies ◽  
Proper Solution ◽  
Buckling Behavior ◽  
Post Buckling ◽  
Helical Buckling ◽  
Lateral Friction

Summary In this paper, the buckling equation and natural boundary conditions are derived with the aid of calculus of variations. The natural and geometric boundary conditions are used to determine the proper solution that represents the post-buckling configuration. Effects of friction and boundary conditions on the critical load of helical buckling are investigated. Theoretical results show that the effect of boundary conditions on helical buckling becomes negligible for a long pipe with dimensionless length greater than 5π Velocity analysis shows that lateral friction becomes dominant at the instant of buckling initiation. Thus, friction can increase the critical load of helical buckling significantly. However, once buckling is initiated, axial velocity becomes dominant again and lateral friction becomes negligible for post-buckling behavior and axial-load-transfer analysis. Consequently, it is possible to seek an analytical solution for the buckling equation. Analytical solutions for both sinusoidal and helical post-buckling configurations are derived, and a practical procedure for modeling of axial load transfer is proposed. To verify the proposed model and analytical results, the authors also conducted experimental studies. Experimental results support the proposed solutions.

Buckling of Porcine Aorta Under Static and Dynamic Loading

2012 ◽  
Author(s):  
Mobin Rastgar Agah ◽  
Kaveh Laksari ◽  
Kurosh Darvish ◽  
Alexander Rachev
Keyword(s):  
Blood Vessels ◽  
Dynamic Loading ◽  
Motor Vehicle ◽  
Vascular System ◽  
Experimental Studies ◽  
Dynamic Buckling ◽  
Traumatic Rupture ◽  
Buckling Behavior ◽  
Static And Dynamic Loading ◽  
Original Configuration

Tortuosity and buckling of blood vessels are defined as the deviation from original configuration and has been observed throughout the vascular system. The blood flow in the regions down-stream of tortuous section decreases, which may cause a deficiency in blood supply to the organs and ischemia. Although tortuosity of blood vessels has been associated with aging, atherosclerosis, hypertension, genetic and other cardiovascular disease, the mechanism behind its initiation and development is not yet understood. In a series of theoretical and experimental studies, biomechanical aspects of buckling of arteries has been investigated under quasi-static loading (Han, 2007; Liu and Han, 2011); however, it has been shown theoretically that the buckling behavior of arteries under dynamic loading are different and arteries may become mechanically unstable at pressures other than the static critical loading (Rachev, 2009). This work addresses buckling of porcine aorta and experimental verification of dynamic buckling in this case. We hypothesize that dynamic buckling can partly contribute to the traumatic rupture of aorta that is a leading cause of fatality in motor vehicle crashes.

Onset and Post Buckling of Pipe-in-Pipe’s Helical Buckling Using Improved Energy Method

2018 ◽  
Author(s):  
Lixin Gong
Keyword(s):  
Potential Energy ◽  
Energy Method ◽  
Normal Force ◽  
Horizontal Wells ◽  
Energy Methods ◽  
Buckling Mode ◽  
Buckling Behavior ◽  
Post Buckling ◽  
Helical Buckling ◽  
Remarkable Agreement

The purpose of this paper is to present theoretical solutions based on an improved energy method for predicting the helical buckling (HB) behavior of pipes in vertical, inclined, and horizontal wells. The energy method has been applied to solve the pipe-in-pipe’s (PIP) helical buckling behavior since Lubinski, et al [2] in the 1950’s. However, in the preceding studies, the energy methods are not yet completely correct because the pipe’s potential energy of the distributed contact normal force induced by the helical buckling was considered to be negligible. This deficiency caused improper deductive procedures. In this paper, the energy method is improved by adding the term of the potential energy of the distributed contact normal force. With this improvement, not only can the PIP’s critical helical buckling forces be successfully derived, but it also provides a deeper insight on the PIP’s helical buckling onset, as well as the post helical buckling behavior. For inclined and horizontal wells, equations are provided to determine the critical forces required to initiate the helical buckling mode for both “long” and “short” pipes. In addition, the post buckling behavior is also described, and a new concept of helical buckling zone (HBZ) for “short” pipes is introduced based on the force-pitch plots as an area in-between the helical buckling’s onset curve and the classical Lubinski curve. Finite element ABAQUS models have also been utilized to confirm the analysis using the improved energy method. And the ABAQUS results show remarkable agreement with the theoretical solutions.

Buckling Behavior of Arteries Under Torsion

2011 ◽  
Author(s):  
Justin R. Garcia ◽  
Shawn D. Lamm ◽  
Hai-Chao Han
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Blood Vessels ◽  
High Blood Pressure ◽  
Atherosclerotic Plaque ◽  
Vascular Grafts ◽  
Vascular Diseases ◽  
The Body ◽  
Buckling Behavior ◽  
Surgical Implantation

Arterial tortuosity is a phenomenon which is observed throughout the body and is associated with aging, diabetes, high blood pressure, and other vascular diseases [1]. Tortuous arteries significantly hinder blood flow which may lead to the development of atherosclerotic plaque buildup [2]. Blood vessels may also become twisted or demonstrate 3-D tortuous shapes when subject to large twist deformations such as during surgical implantation of vascular grafts, propeller flap procedures, stent-artery interactions, and sudden movements of the neck or limbs [4–6]. However, the twisting behavior of arteries is poorly understood.

Effect of Coiled Tubing Initial Configuration on Buckling Behavior in Deviated Wells

1999 ◽  
Vol 121 (3) ◽  
pp. 176-182 ◽  
Author(s):  
W. Y. Qiu ◽  
S. Z. Miska ◽  
L. J. Volk
Keyword(s):  
Virtual Work ◽  
Initial Configuration ◽  
Initial Amplitude ◽  
Principle Of Virtual Work ◽  
Conservation Of Energy ◽  
Numerical Examples ◽  
Coiled Tubing ◽  
Buckling Behavior ◽  
Helical Buckling ◽  
Deviated Wells

Current sinusoidal and helical buckling models are valid only for initially straight coiled tubing (CT). This paper stresses the effect of the pipe initial configuration (residual bending) on the sinusoidal and helical buckling behaviors in deviated wells. Using the conservation of energy and the principle of virtual work, new general equations are derived for predicting the sinusoidal and helical configurations of CT. These new equations reduce to those previously published when the CT is initially straight in deviated wells. Numerical examples are provided to show the effect of the initial amplitude, the inclination angle, and the size of a borehole on the sinusoidal and helical buckling behaviors of CT with the residual bending.

Author response for "Hemovasculogenic origin of blood vessels in the developing mouse brain"

2020 ◽  
Author(s):  
Miguel A. Gama Sosa ◽  
Rita De Gasperi ◽  
Gissel M. Perez ◽  
Patrick R. Hof ◽  
Gregory A. Elder
Keyword(s):  
Blood Vessels ◽  
Mouse Brain ◽  
Author Response ◽  
Developing Mouse Brain

Evidence for a Blood Ganglion Barrier in the Superior Cervical Ganglion of the Rat

1982 ◽  
Vol 40 ◽  
pp. 204-204
Author(s):  
D. M. DePace
Keyword(s):  
Blood Vessels ◽  
Superior Cervical Ganglion ◽  
Peripheral Nerves ◽  
Time Schedule ◽  
Transmission Electron ◽  
Cervical Ganglion ◽  
The Central Nervous System ◽  
Cervical Ganglia ◽  
Capillary Circulation ◽  
And Control

The majority of blood vessels in the superior cervical ganglion possess a continuous endothelium with tight junctions. These same features have been associated with the blood brain barrier of the central nervous system and peripheral nerves. These vessels may perform a barrier function between the capillary circulation and the superior cervical ganglion. The permeability of the blood vessels in the superior cervical ganglion of the rat was tested by intravenous injection of horseradish peroxidase (HRP). Three experimental groups of four animals each were given intravenous HRP (Sigma Type II) in a dosage of.08 to.15 mg/gm body weight in.5 ml of.85% saline. The animals were sacrificed at five, ten or 15 minutes following administration of the tracer. Superior cervical ganglia were quickly removed and fixed by immersion in 2.5% glutaraldehyde in Sorenson's.1M phosphate buffer, pH 7.4. Three control animals received,5ml of saline without HRP. These were sacrificed on the same time schedule. Tissues from experimental and control animals were reacted for peroxidase activity and then processed for routine transmission electron microscopy.

Permeability of Endometrial Blood Vessels to Exogenous Horse Radish Peroxidase in Mice. Electron Microscope Study

1973 ◽  
Vol 31 ◽  
pp. 562-563
Author(s):  
M.C. Castillo-Jessen ◽  
A. González-Angulo
Keyword(s):  
Electron Microscopy ◽  
Blood Vessels ◽  
Electron Microscope Study ◽  
Ultrastructural Level ◽  
Low Molecular Weight ◽  
Horse Radish Peroxidase ◽  
Intravascular Injection ◽  
Normal Morphology ◽  
Functional Implications ◽  
Low Molecular Weight Proteins

Information regarding the normal morphology of uterine blood vessels at ultrastructural level in mammals is scarce Electron microscopy studies dealing with endometrial vasculature despite the functional implications due to hormone priming are not available. Light microscopy observations with combined injection of dyes and microradiography along with histochemical studies does not enable us to know the detailed fine structure of the possible various types of blood vessels in this tissue. The present work has been designed to characterize the blood vessels of endometrium of mice as well as the behavior of the endothelium to injection of low molecular weight proteins during the normal estrous cycle in this animal. One hundred and forty female albino mice were sacrificed after intravascular injection of horse radish peroxidase (HRP) at 30 seconds, 5, 15, 30 and 60 minutes.

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