Scattering of Plane Sh-Wave From a Partially Debonded Shallow Cylindrical Elastic Inclusion

2009 ◽  
Vol 25 (4) ◽  
pp. 411-419 ◽  
Author(s):  
J.X. Zhao ◽  
H. Qi
Keyword(s):  
Boundary Condition ◽  
Wave Function ◽  
Half Space ◽  
Standing Wave ◽  
Elastic Inclusion ◽  
Complex Function ◽  
Surface Displacement ◽  
Sh Wave ◽  
Interface Cracks ◽  
Plane Sh Wave

ABSTRACTThe scattering of plane SH-wave from a partially debonded shallow cylindrical elastic inclusion in half space is investigated in this paper by complex function method and expansion method of wave function. The debonding regions are considered as multiple arc-shaped interface cracks with non-contacting faces. Firstly, in the inclusion district, the standing wave function in the elastic inclusion with unknown coefficients which satisfies the boundary condition is constructed and generated into the Fourier series; in the half space, the stress and displacement boundary condition around the elastic inclusion can be modeled as the same as the standing wave function in the elastic inclusion. Then, a set of infinite algebraic equations can be obtained around the same boundary and the solution of problem can be gained. In the end, numerical examples of the surface displacement are provided and discussed. It is found that the interface cracks can raise the surface displacement amplitudes to a certain degree.

The Scattering Field of SH-Wave in Half-Space With a Semi-Cylindrical Hill and a Horizontal Circular Tunnel

2005 ◽  
Author(s):  
Guoqing Wang ◽  
Liming Dai ◽  
Diankui Liu
Keyword(s):  
Wave Function ◽  
Half Space ◽  
Stress Condition ◽  
Complex Function ◽  
Sh Wave ◽  
Coordinate Method ◽  
Linear Algebraic Equations ◽  
Scattering Field ◽  
Moving Coordinate ◽  
The Hill

The scattering field of SH-wave in a half-space with a semi-cylindrical hill and a subsurface horizontal hole is studied in the present research by utilizing a complex function and the moving-coordinate method. Based on the concept of ‘conjunction,’ the domain considered is divided into two subdomains. The first subdomain is a cylindrical one which includes the surface of the hill, while the rest is the second subdomain. In the cylindrical subdomain, a standing wave function is constructed which automatically satisfies the zero-stress condition at the hill surface and arbitrary-stress condition at the other part of the circular subdomain. For the second subdomain, which contains a semi-cylindrical canyon and a subsurface hole, a scattering wave function is assumed, which satisfies the zero-stress condition on the horizontal surface. By employing the moving-coordinate method, the solutions of the mathematical model established for the SH-wave can be obtained with the satisfaction of the continuous conditions of stress and displacement across the junction interface together with the zero-stress condition at the surface of the tunnel. The solutions such obtained consist of a series of infinite linear algebraic equations, which can be solved numerically with consideration of the first finite terms corresponding to the frequencies of the wave. For demonstrating the application of the model developed, the displacements of the horizontal and semi-cylindrical hill surfaces are quantified with different properties of wave and geometry parameters.

Interaction of SH-Wave on Multiple Linear Cracks near Shallow-Embedded Structure

2011 ◽  
Vol 488-489 ◽  
pp. 440-443
Author(s):  
Zai Lin Yang ◽  
Hua Nan Xu ◽  
Mei Juan Xu ◽  
Bai Tao Sun
Keyword(s):  
Green’S Function ◽  
Half Space ◽  
Green's Function ◽  
Complex Function ◽  
Surface Displacement ◽  
Elastic Half Space ◽  
Polar Coordinates ◽  
Multiple Cracks ◽  
Sh Wave ◽  
Lining Structure

The surface displacement of a circular lining structure and multiple cracks in an elastic half space by incident SH-wave is studied in this paper based on the methods of Green's function, complex function and multi-polar coordinates. Firstly, we construct a suitable Green’s function which indicates a fundamental solution to the displacement field for an elastic half space possessing a circular lining structure and cracks while bearing out-plane harmonic line loads at arbitrary point. Then using the method of crack-division, a crack is created. Thus expressions of displacement and stress field are established at the existence of the structure and the cracks. Finally, the interaction of inclusion and two cracks is chosen as numerical examples and the influences of different parameters on the surface displacement are discussed.

Dynamic Response of Shallow Buried Tunnel Subjected to SH Wave

2010 ◽  
Vol 163-167 ◽  
pp. 4265-4268
Author(s):  
Zhi Gang Chen
Keyword(s):  
Stress Concentration ◽  
Half Space ◽  
Dynamic Stress ◽  
Complex Function ◽  
Least Square ◽  
Wave Number ◽  
Dynamic Stress Concentration ◽  
Algebraic Equations ◽  
Sh Wave ◽  
Scattering Wave

The dynamic stress concentration on quadratic and U-shaped cavities in half space, which are similar to the cross-section of the tunnels, is solved in this paper impacted by SH-wave. The analytical solution for the cavity in elastic half space is gained by the complex function method. In the complex plane, the scattering wave which satisfies the zero-stress condition at the horizontal surface can be constructed, the problem can be inverted into a set of algebraic equations to solve coefficients of the constructed scattering wave by least square method. For the earthquake-resistance researches, the numerical examples of the dynamic stress concentration around the quadratic and U-shaped cavities impacted by SH-wave are given. The influences of the dynamic stress concentration by the incident wave number and angle, the depth and shape of the cavity are discussed. It is showed that the interaction among the wave, the surface and the shallow buried tunnels should be cared in half space. In this situation, the dynamic stress concentration around the tunnel is greater obvious than the whole space.

Scattering of SH-Wave by an Interface Cylindrical Elastic Inclusion with a Semicircular Debonded above Subsurface Cavity

2013 ◽  
Vol 753-755 ◽  
pp. 1846-1850
Author(s):  
Chun Xiang Zhao ◽  
Hui Qi ◽  
Jing Fu Nan
Keyword(s):  
Green Function ◽  
Elastic Inclusion ◽  
Complex Function ◽  
Fredholm Integral Equations ◽  
Circular Cavity ◽  
Sh Wave ◽  
Polar Coordinate ◽  
Set Up ◽  
Material Space ◽  
Horizontal Interface

The Scattering of SH-wave by a cylindrical elastic inclusion on horizontal interface in bi-material space with a semicircular debonded above subsurface circular cavity have been considered using the methods of complex function and Green function. Firstly, we divide the solution domain along the interface and disconnected boundary into two half-spaces, an upper one and a lower one. And Green function was constructed by using the methods of complex function and multi-polar coordinate. Secondly, the bi-material media was connected along the horizontal interface using the idea of interface conjunction, then undetermined anti-plane forces were loaded at the linking sections respectively to satisfy continuity conditions, and a series of Fredholm integral equations of the first kind to determine that the unknown forces could be set up through continuity conditions on surface. Finally, some examples for DSCF around cylindrical elastic inclusion edge are presented and discussed. Numerical results show that subsurface circular cavitys existence notablely influences DSCF of around cylindrical elastic inclusion edge with a semicircular debonded above subsurface circular cavity.

The Interaction of a Cylindrical Elastic Inclusion with Semicircular Disconnected Curve and Linear Cracks in an Homogeneous Medium by SH-Waves

2007 ◽  
Vol 348-349 ◽  
pp. 357-360
Author(s):  
Qi Hui ◽  
Jia Xi Zhao
Keyword(s):  
Green’S Function ◽  
Half Space ◽  
Green's Function ◽  
Function Method ◽  
Dynamic Stress ◽  
Elastic Inclusion ◽  
Complex Function ◽  
Dynamic Stress Intensity Factor ◽  
Homogeneous Medium ◽  
Sh Waves

The scattering of SH waves by a cylindrical elastic inclusion with a semicircular disconnected curve and linear cracks in an homogeneous medium is investigated and the solution of dynamic stress intensity factor is given by Green’s function, complex function method. Firstly, we can divide the space into up-and-down parts along the X axis. In the lower half space, a new suitable Green’s function for the present problem is constructed.In the upper half space, the Green’s function has been given by reference [5]. Thereby the semicircular disconnected curve can be constructed when the two parts are bonded along the interface and the linear cracks can be constructed using the method of crack-division and the integral equations can be obtained by the use of continuity conditions at the X axis. Finally, some examples and results of dynamic stress intensify factor are given and the influence of the parameters is discussed.

Scattering of SH Wave by an Interacting Mode III Crack and a Circular Cavity in Half Space

2007 ◽  
Vol 348-349 ◽  
pp. 861-864 ◽  
Author(s):  
Zai Lin Yang ◽  
Zhi Gang Chen ◽  
Dian Kui Liu
Keyword(s):  
Green’S Function ◽  
Half Space ◽  
Green's Function ◽  
Displacement Field ◽  
Complex Function ◽  
Dynamic Stress Intensity Factor ◽  
Arbitrary Point ◽  
Circular Cavity ◽  
Sh Wave ◽  
Mode Iii

Scattering of SH wave by an elastic half space with a circular cavity and a crack in any position and direction is studied with Green’s function, complex function and multi-polar coordinate method. First, a suitable Green’s function is constructed, which is the fundamental solution of the displacement field for a half space with a circular cavity impacted by an out-plane harmonic line source loading at an arbitrary point in half space. Then a crack in any position and direction is constructed by means of crack-division in half space. Finally the displacement field and stress field are established in the case of coexistence of circular cavity and crack, and the expression of dynamic stress intensity factor (DSIF) at the tip of crack is given. According to numerical examples, the influences of different parameters on DSIF are discussed.

The Scattering of SH-Wave Caused by Subsurface Circular Cavities in a Layered Half-Space

2011 ◽  
Vol 488-489 ◽  
pp. 226-229
Author(s):  
Dong Ni Chen ◽  
Hui Qi ◽  
Yong Shi
Keyword(s):  
Half Space ◽  
Elastic Layer ◽  
Complex Function ◽  
Expansion Method ◽  
Elastic Half Space ◽  
Wave Functions ◽  
Large Radius ◽  
Algebraic Equations ◽  
Sh Wave ◽  
Linear Algebraic Equations

The scattering of SH-wave caused by the subsurface circular cavities in an elastic half-space covered with an elastic layer was discussed, which was based on the complex function method ,wave functions expansion method and big circular arc postulation method in which the circular boundary of large radius was used to approximate straight boundary of surface elastic layer. By the theory of Helmholtz, the general solution of the Biot’s wave function was achieved. Utilizing the complex series expansion technology and the boundary conditions, we could transform the present problem into the problem in which we needed to solve the infinite linear algebraic equations with unknown coefficients in wave functions. Finally, the dynamic stress concentration factors around the circular cavities were discussed in numerical examples.

Surface Displacement of a Semi-Cylindrical Hill above a Subsurface Elastic Cylindrical Inclusion under SH-Wave

2011 ◽  
Vol 243-249 ◽  
pp. 4037-4040
Author(s):  
Xiao Tang Lv
Keyword(s):  
Boundary Condition ◽  
Boundary Conditions ◽  
Complex Variable ◽  
Surface Displacement ◽  
Cylindrical Inclusion ◽  
Computational Results ◽  
Algebraic Equations ◽  
Sh Wave ◽  
Complex Variable Function ◽  
Variable Function

Scattering of SH-wave by a semi-cylindrical hill above a subsurface elastic cylindrical inclusion in half-space is studied by complex variable function. Firstly, the whole solution domain is divided into two parts, and the solutions that satisfied the boundary conditions are constructed in two parts respectively. Then according to the “conjunction” condition of junction interface and the boundary condition around the subsurface elastic cylindrical inclusion, a set of infinite algebraic equations about the problem can be obtained. Finally the computational results of surface displacement were provided and discussed.

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