Nonaxisymmetric Dynamic Response of Imperfectly Bonded Buried Fluid-Filled Orthotropic Cylindrical Shells

1996 ◽  
Vol 118 (1) ◽  
pp. 64-73 ◽  
Author(s):  
J. P. Dwivedi ◽  
V. P. Singh ◽  
P. C. Upadhyay
Keyword(s):  
Cylindrical Shell ◽  
Wave Propagation ◽  
Dynamic Response ◽  
Longitudinal Wave ◽  
Orthotropic Cylindrical Shell ◽  
Soil Conditions ◽  
Thick Shell ◽  
Fluid Density ◽  
Acoustic Equation ◽  
Plane Longitudinal Wave

This paper is concerned with the nonaxisymmetric dynamic response of an imperfectly bonded fluid-filled buried orthotropic cylindrical shell excited by a plane longitudinal wave. A thick shell model, including the effect of shear deformation and rotary inertia, has been taken. For the wave propagation in the fluid inside the pipe, linear acoustic equation has been used. The effects of fluid presence on the shell displacements have been studied for different soil conditions and at various angles of incidence of the longitudinal wave. The effects of bond imperfection on the shell response have been compared with the effects realized due to the presence of fluid inside the pipeline. Effects of changes in the fluid density are also discussed. It is found that magnitude of the response of fluid-filled pipeline can become even more than that of an empty pipeline (without fluid), and, hence, it cannot be assumed that a fluid-filled pipeline will always furnish safe and conservative response.

Influence of Shell Thickness on Axisymmetric Longitudinal Wave Propagation in Double Layered Hollow Cylindrical Shell Structure

2012 ◽  
Vol 256-259 ◽  
pp. 954-959
Author(s):  
Kang Hua Gao
Keyword(s):  
Cylindrical Shell ◽  
Wave Propagation ◽  
Longitudinal Wave ◽  
Shell Structure ◽  
Shell Thickness ◽  
Wave Theory ◽  
Continuity Condition ◽  
Wave Number ◽  
Continuous Contact ◽  
Longitudinal Wave Propagation

Based on elastic wave theory, the characteristics for axisymmetric longitudinal wave propagation in double layered hollow cylindrical shell structure with a continuous contact interface are investigated. According to free boundary conditions and interfacial contact continuity condition, the first mode non-dimension dispersion equations for longitudinal wave is derived and validated by calculation data of existing literature. The non-dimension expressions of stress and displacement are deduced and the stress and displacement distribution in cylindrical shell are obtained by calculation examples. Under the fixed outside radius condition, the shell thickness influence on dispersion relation of axisymmetric longitudinal wave and stress and displacement fields in cylindrical shell are discussed. The results show that the thickness of inner shell or outer shell has little influence on dispersion characteristics when the value of wave number is small. As wave number increased, the effect of shell thickness also increased. The stress and displacement in shell increase with the increase of the thickness of inner or outer layer shell when the wave number value is large.

scholarly journals Analytical mathematical schemes: Circular rod grounded via transverse Poisson’s effect and extensive wave propagation on the surface of water

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 545-554
Author(s):  
Asghar Ali ◽  
Aly R. Seadawy ◽  
Dumitru Baleanu
Keyword(s):  
Wave Propagation ◽  
Partial Differential Equations ◽  
Differential Equations ◽  
Longitudinal Wave ◽  
Symbolic Computation ◽  
Boussinesq Equation ◽  
Nonlinear Partial Differential Equations ◽  
Wave Model ◽  
Simple Equation ◽  
Partial Differential

AbstractThis article scrutinizes the efficacy of analytical mathematical schemes, improved simple equation and exp(-\text{Ψ}(\xi ))-expansion techniques for solving the well-known nonlinear partial differential equations. A longitudinal wave model is used for the description of the dispersion in the circular rod grounded via transverse Poisson’s effect; similarly, the Boussinesq equation is used for extensive wave propagation on the surface of water. Many other such types of equations are also solved with these techniques. Hence, our methods appear easier and faster via symbolic computation.

Collapse of Arteries Subjected to an External Band of Pressure

1980 ◽  
Vol 102 (1) ◽  
pp. 8-22 ◽  
Author(s):  
A. M. Hecht ◽  
H. Yeh ◽  
S. M. K. Chung
Keyword(s):  
Reynolds Number ◽  
Blood Flow ◽  
Cylindrical Shell ◽  
Orthotropic Cylindrical Shell ◽  
Reynolds Numbers ◽  
Intraluminal Pressure ◽  
Collapse Pressure ◽  
Vessel Size ◽  
Flow Reynolds Number ◽  
Small Band

Collapse of arteries subjected to a band of hydrostatic pressure of finite length is analyzed. The vessel is treated as a long, thin, linearly elastic, orthotropic cylindrical shell, homogeneous in composition, and with negligible radial stresses. Blood in the vessel is treated as a Newtonian fluid and the Reynolds number is of order 1. Results are obtained for effects of the following factors on arterial collapse: intraluminal pressure, length of the pressure band, elastic properties of the vessel, initial stress both longitudinally and circumferentially, blood flow Reynolds number, compressibility, and wall thickness to radius ratio. It is found that the predominant parameter influencing vessel collapse for the intermediate range of vessel size and blood flow Reynolds numbers studied is the preconstricted intraluminal pressure. For pressure bands less than about 10 vessel radii the collapse pressure increases sharply with increasing intraluminal pressure. Initial axial prestress is found to be highly stabilizing for small band lengths. The effects of fluid flow are found to be small for pressure bands of less than 100 vessel radii. No dramatic orthotropic vessel behavior is apparent. The analysis shows that any reduction in intraluminal pressure, such as that produced by an upstream obstruction, will significantly lower the required collapse pressure. Medical implications of this analysis to Legg-Perthes disease are discussed.

Sign in / Sign up

Export Citation Format

Share Document