scholarly journals Surface Effect on Diffractions of Elastic Waves and Stress Concentration near a Cluster of Cylindrical Nanoholes Arranged as Quadrate Shape

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Ru Yan
Keyword(s):  
Stress Concentration ◽  
Multiple Scattering ◽  
Elastic Waves ◽  
Surface Effect ◽  
Surface Elasticity ◽  
Expansion Method ◽  
Potential Method ◽  
P Wave ◽  
Displacement Potential ◽  
P And Sv Waves

We consider the multiple scattering of elastic waves (P-wave and SV-wave) by a cluster of nanosized cylindrical holes arranged as quadrate shape. When the radius of the holes shrinks to nanometers, the surface elasticity theory is adopted in analysis. Using the displacement potential method and wave functions expansion method, we obtain that the multiple scattering fields induced by incident P- and SV-waves around the holes are derived. The dynamic stress concentration around the holes is calculated to illustrate the effect of surface effects on the multiple scattering of P- and SV-waves.

Diffractions of Elastic Waves and Stress Concentration Near a Cylindrical Nano-Inclusion Incorporating Surface Effect

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Y. Ru ◽  
G. F. Wang ◽  
T. J. Wang
Keyword(s):  
Stress Concentration ◽  
Elastic Waves ◽  
Surface Effect ◽  
Potential Method ◽  
P Wave ◽  
Compressional Waves ◽  
Displacement Potential ◽  
Elastic Fields ◽  
P And Sv Waves ◽  
Incident Waves

The diffractions of plane compressional waves (P-wave) and shear waves (SV-wave) by a cylindrical nano-inclusion are investigated in this paper. To account for the surface/interface effect at nanoscale, the surface/interface elasticity theory is adopted in the analysis. Using the displacement potential method, we obtain the solutions for the elastic fields induced by incident P- and SV-waves near a cylindrical nano-inclusion. The results show that surface/interface has a significant effect on the diffractions of elastic waves as the radius of the inclusion shrinks to nanoscale. For incident waves with different frequencies, the effects of interfacial properties on the dynamic stress concentration around the nano-inclusion are discussed in detail.

Effects of Surface Elasticity on Scattering of P Waves by an Elastic Half-Plane with a Nanosized Semi-Cylindrical Inclusion

2013 ◽  
Vol 303-306 ◽  
pp. 2661-2666
Author(s):  
Zhi Ying Ou ◽  
Cheng Liu ◽  
Xiao Wei Liu
Keyword(s):  
Surface Energy ◽  
Half Plane ◽  
Surface Effect ◽  
Surface Elasticity ◽  
Expansion Method ◽  
Cylindrical Inclusion ◽  
P Waves ◽  
Wave Function Expansion Method ◽  
Plane P Waves ◽  
Incident Waves

The scattering of plane P waves by a nanosized semi-cylindrical inclusion embedded in an elastic half-plan has been studied in this paper. To account for the surface effect at nanoscale, the surface elasticity is also adopted. When the boundary condition at the straight edge of the half-plane is traction free, the analytical solutions of stress fields of the half plan with semi-cylindrical inclusion are expressed by employing a wave function expansion method. The results show that surface energy has a significant effect on the scattering of plane P waves as the radius of the semi-cylindrical inclusion shrinks to nanoscale. For incident waves with different frequencies, radius of semi-cylindrical inclusion, the effects of surface energy on the dynamic stress concentration near the semi-cylindrical inclusion are discussed in detail.

scholarly journals Study on the Single Scattering of Elastic Waves by a Cylindrical Fiber with a Partially Imperfect Bonding Using the Collocation Point Method

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Jun Zhang ◽  
Longhai Zeng ◽  
Chuanlin Hu ◽  
Wensheng Yan
Keyword(s):  
Elastic Waves ◽  
Collocation Point ◽  
Single Scattering ◽  
Imperfect Interface ◽  
P Wave ◽  
Imperfect Bonding ◽  
Imperfect Interfaces ◽  
Cylindrical Fiber ◽  
P And Sv Waves ◽  
Wave Incidence

The single scattering of P- and SV-waves by a cylindrical fiber with a partially imperfect bonding to the surrounding matrix is investigated, which benefits the characterization of the behavior of elastic waves in composite materials. The imperfect interface is modelled by the spring model. To solve the corresponding single scattering problem, a collocation point (CP) method is introduced. Based on this method, influence of various aspects of the imperfect interface on the scattering of P- and SV-waves is studied. Results indicate that (i) the total scattering cross section (SCS) is almost symmetric about the axis α=π/2 with respect to the location (α) of the imperfect interface, (ii) imperfect interfaces located at α=0 and α=π highly reduce the total SCS under a P-wave incidence and imperfect interfaces located at α=π/2 reduce the total SCS most significantly under SV-incidence, and (iii) under a P-wave incidence the SCS has a high sensitivity to the bonding level of imperfect interfaces when α is small, while it becomes more sensitive to the bonding level when α is larger under SV-wave incidence.

EFFECTS OF INTERFACE ENERGY ON MULTIPLE SCATTERING OF PLANE COMPRESSIONAL WAVES BY TWO CYLINDRICAL FIBERS

2012 ◽  
Vol 04 (04) ◽  
pp. 1250040 ◽  
Author(s):  
Z. Y. OU ◽  
D. W. LEE
Keyword(s):  
Surface Energy ◽  
Multiple Scattering ◽  
Surface Elasticity ◽  
Expansion Method ◽  
Interface Energy ◽  
Dynamic Mechanical Properties ◽  
Addition Theorem ◽  
Inhomogeneous Materials ◽  
Compressional Waves ◽  
Eigenfunction Expansion Method

The multiple scattering of plane compressional waves by two cylindrical fibers with interface effects is investigated. Based on surface elasticity theory, the wave fields in a nanoscale solid medium can be obtained by applying the eigenfunction expansion method and the Graf's addition theorem. Our results indicate that surface energy significantly affects the diffraction of elastic waves, as the radii of the fibers approach nanometers. The dynamic stress concentration factors at the interfaces between the fibers and the matrix under incident plane compressional waves at different frequencies are examined to determine the effects of surface energy, properties of inhomogeneous materials, and the interaction between fibers in multiple scattering phenomena. These results are helpful in understanding the dynamic mechanical properties of nanocomposites, and the proposed method for investigating the multiple scattering of plane compressional waves can be extended to the case of fiber-reinforced composites.

scholarly journals Low frequency scattering of elastic waves by a cavity using a matched asymptotic expansion method

1995 ◽  
Vol 37 (1) ◽  
pp. 99-120 ◽  
Author(s):  
L. Bencheikh
Keyword(s):  
Elastic Waves ◽  
Elliptic Boundary ◽  
Low Frequency ◽  
Expansion Method ◽  
Integral Equation Method ◽  
Boundary Integral ◽  
P Wave ◽  
Matched Asymptotic Expansion ◽  
Scattering Of Elastic Waves ◽  
Diffraction Of Elastic Waves

AbstractThis work deals with low-frequency asymptotic solutions using the method of matched asymptotic expansions. It is based on two papers by Buchwald [3] and Buchwald and Tran Cong [4] who studied the diffraction of elastic waves by a small circular cavity and a small elliptic cavity, respectively, in an otherwise unbounded domain. Here we clarify and systematize some aspects of their work and extend it to the diffraction of elastic waves by a small cylindrical cavity with a hypotrochoidal boundary. Results for the case of an incident P-wave are compared, in the special case of an elliptic boundary, with the results from the numerical solution of the boundary integral equation method.

scholarly journals On the Stress Transfer of Nanoscale Interlayer with Surface Effects

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Quan Yuan ◽  
Mengjun Wu
Keyword(s):  
Surface Effect ◽  
Surface Elasticity ◽  
Stress Transfer ◽  
Interfacial Stress ◽  
Interlayer Thickness ◽  
Shear Lag ◽  
Multilayered Structures ◽  
Residual Surface Stress ◽  
Shear Lag Model ◽  
Lag Model

An improved shear-lag model is proposed to investigate the mechanism through which the surface effect influences the stress transfer of multilayered structures. The surface effect of the interlayer is characterized in terms of interfacial stress and surface elasticity by using Gurtin–Murdoch elasticity theory. Our calculation result shows that the surface effect influences the efficiency of stress transfer. The surface effect is enhanced with decreasing interlayer thickness and elastic modulus. Nonuniform and large residual surface stress distribution amplifies the influence of the surface effect on stress concentration.

Polar radiation patterns of P and SV waves in a multi-layered medium

1973 ◽  
Vol 63 (2) ◽  
pp. 529-547
Author(s):  
Tien-Chang Lee ◽  
Ta-Liang Teng
Keyword(s):  
Displacement Field ◽  
Layered Medium ◽  
Focal Depth ◽  
Focal Mechanisms ◽  
P Wave ◽  
Wave Radiation ◽  
Radiation Patterns ◽  
Double Couple ◽  
Spatial Coordinates ◽  
P And Sv Waves

abstract The displacement field in a multi-layered medium due to incident plane P or SV waves is formulated in terms of Haskell's layer matrices. Based on the reciprocity theorem, the far-field polar radiation patterns of single force, double force, single couple, double couple, and dilatation in a multi-layered medium can be obtained from the displacement field and its first derivatives with respect to the spatial coordinates. Numerical results for models of one layer overlying a half-space indicate that (1) the radiation patterns are sensitive to the variation of focal depth, (2) the layering has a more pronounced effect on SV-wave radiation patterns than on P-wave radiation patterns, (3) the radiation patterns become simpler as the wavelength increases, (4) polarity may reverse abruptly somewhere beyond the critical angle in SV-wave radiation patterns, (5) radiation may be discontinuous across interfaces for some assumed focal mechanisms applied slightly above and below the interfaces, and (6) no clearcut distinction among the various radiation patterns can be used to single out one type of the assumed focal mechanisms from the rest.

A computer program for the application of Zoeppritz's amplitude equations and Knott's energy equations

1976 ◽  
Vol 66 (6) ◽  
pp. 1881-1885 ◽  
Author(s):  
G. B. Young ◽  
L. W. Braile
Keyword(s):  
Computer Program ◽  
Elastic Waves ◽  
Displacement Amplitude ◽  
Plane Interface ◽  
Angle Of Incidence ◽  
Amplitude Equations ◽  
Elastic Solids ◽  
Displacement Potential ◽  
Energy Equations ◽  
Sample Case

abstract A computer program is presented which calculates Zoeppritz's displacement amplitude coefficients, displacement potential coefficients, and Knott's energy coefficients for plane harmonic elastic waves of P or SV type incident on a plane interface between two isotropic, homogeneous elastic solids. A discussion of these three basic types of coefficients is included. Results of applying the program to a sample case are presented in the form of a graph of the energy coefficients computed for all possible wave types and over a range of angle of incidence of 0° to 90°.

Sign in / Sign up

Export Citation Format

Share Document