The exact solutions for the propagation of Love waves in one-dimensional(1D)hexagonal piezoelectric quasicrystal(PQC)nanoplates with surface effects are derived.An electro-elastic model is developed to investigate the...The exact solutions for the propagation of Love waves in one-dimensional(1D)hexagonal piezoelectric quasicrystal(PQC)nanoplates with surface effects are derived.An electro-elastic model is developed to investigate the anti-plane strain problem of Love wave propagation.By introducing three shape functions,the wave equations and electric balance equations are decoupled into three uncorrelated problems.Satisfying the boundary conditions of the top surface on the covering layer,the interlayer interface,and the matrix,a dispersive equation with the influence of multi-physical field coupling is provided.A surface PQC model is developed to investigate the surface effects on the propagation behaviors of Love waves in quasicrystal(QC)multilayered structures with nanoscale thicknesses.A novel dispersion relation for the PQC structure is derived in an explicit closed form according to the non-classical mechanical and electric boundary conditions.Numerical examples are given to reveal the effects of the boundary conditions,stacking sequence,characteristic scale,and phason fluctuation characteristics on the dispersion curves of Love waves propagating in PQC nanoplates with surface effects.展开更多
Based on the couple-stress theory,the elastohydrodynamic lubrication(EHL)contact is analyzed with a consideration of the size effect.The lubricant between the contact surface of a homogeneous coated half-plane and a r...Based on the couple-stress theory,the elastohydrodynamic lubrication(EHL)contact is analyzed with a consideration of the size effect.The lubricant between the contact surface of a homogeneous coated half-plane and a rigid punch is supposed to be the non-Newtonian fluid.The density and viscosity of the lubricant are dependent on fluid pressure.Distributions of film thickness,in-plane stress,and fluid pressure are calculated by solving the nonlinear fluid-solid coupled equations with an iterative method.The effects of the punch radius,size parameter,coating thickness,slide/roll ratio,entraining velocity,resultant normal load,and stiffness ratio on lubricant film thickness,in-plane stress,and fluid pressure are investigated.The results demonstrate that fluid pressure and film thickness are obviously dependent on the size parameter,stiffness ratio,and coating thickness.展开更多
This paper studies the contact vibration problem of an elastic half-space coated with functionally graded materials(FGMs)subject to a rigid spherical punch.A static force superimposing a dynamic time-harmonic force ac...This paper studies the contact vibration problem of an elastic half-space coated with functionally graded materials(FGMs)subject to a rigid spherical punch.A static force superimposing a dynamic time-harmonic force acts on the rigid spherical punch.Firstly,we give the static contact problem of FGMs by a least-square fitting approach.Next,the dynamic contact pressure is solved by employing the perturbation method.Lastly,the dynamic contact stiffness with different dynamic contact displacement conditions is derived for the FGM coated half-space.The effects of the gradient index,coating thickness,internal friction,and punch radius on the dynamic contact stiffness factor are discussed in detail.展开更多
This paper investigates the dynamic response of a coated half-plane subjected to a harmonic Hertz load on the coating surface.The complex modulus is used to describe the hysteretic damping of the elastic homogeneous c...This paper investigates the dynamic response of a coated half-plane subjected to a harmonic Hertz load on the coating surface.The complex modulus is used to describe the hysteretic damping of the elastic homogeneous coating and half-plane.Using the Helmholtz decomposition and Fourier integral transform technique,we derive the stresses and displacements of the coating and half-plane from Navier5s elasticdynamic equations in the form of complex integrals.Then,the global adaptive quadrature algorithm is exploited to solve the complex integrals numerically.The effects of Young’s modulus ratio,density ratio,coating thickness,loss factor and external excitation frequency are discussed.It is found that the dynamic response of displacements and stresses becomes increasingly oscillatory with the increase in excitation frequency.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.12272402 and11972365)the China Agricultural University Education Foundation(No.1101-2412001)。
文摘The exact solutions for the propagation of Love waves in one-dimensional(1D)hexagonal piezoelectric quasicrystal(PQC)nanoplates with surface effects are derived.An electro-elastic model is developed to investigate the anti-plane strain problem of Love wave propagation.By introducing three shape functions,the wave equations and electric balance equations are decoupled into three uncorrelated problems.Satisfying the boundary conditions of the top surface on the covering layer,the interlayer interface,and the matrix,a dispersive equation with the influence of multi-physical field coupling is provided.A surface PQC model is developed to investigate the surface effects on the propagation behaviors of Love waves in quasicrystal(QC)multilayered structures with nanoscale thicknesses.A novel dispersion relation for the PQC structure is derived in an explicit closed form according to the non-classical mechanical and electric boundary conditions.Numerical examples are given to reveal the effects of the boundary conditions,stacking sequence,characteristic scale,and phason fluctuation characteristics on the dispersion curves of Love waves propagating in PQC nanoplates with surface effects.
基金Project supported by the National Natural Science Foundation of China(Nos.11902217,11725207,12011530056)the Russian Foundation for Basic Research(No.20-58-53045-GFEN-a)。
文摘Based on the couple-stress theory,the elastohydrodynamic lubrication(EHL)contact is analyzed with a consideration of the size effect.The lubricant between the contact surface of a homogeneous coated half-plane and a rigid punch is supposed to be the non-Newtonian fluid.The density and viscosity of the lubricant are dependent on fluid pressure.Distributions of film thickness,in-plane stress,and fluid pressure are calculated by solving the nonlinear fluid-solid coupled equations with an iterative method.The effects of the punch radius,size parameter,coating thickness,slide/roll ratio,entraining velocity,resultant normal load,and stiffness ratio on lubricant film thickness,in-plane stress,and fluid pressure are investigated.The results demonstrate that fluid pressure and film thickness are obviously dependent on the size parameter,stiffness ratio,and coating thickness.
基金Project supported by the National Natural Science Foundation of China(Nos.11725207,12021002,and 12072226)。
文摘This paper studies the contact vibration problem of an elastic half-space coated with functionally graded materials(FGMs)subject to a rigid spherical punch.A static force superimposing a dynamic time-harmonic force acts on the rigid spherical punch.Firstly,we give the static contact problem of FGMs by a least-square fitting approach.Next,the dynamic contact pressure is solved by employing the perturbation method.Lastly,the dynamic contact stiffness with different dynamic contact displacement conditions is derived for the FGM coated half-space.The effects of the gradient index,coating thickness,internal friction,and punch radius on the dynamic contact stiffness factor are discussed in detail.
基金The authors wish to acknowledge the financial support on this study from the National Natural Science Foundation of China(No.11725207).
文摘This paper investigates the dynamic response of a coated half-plane subjected to a harmonic Hertz load on the coating surface.The complex modulus is used to describe the hysteretic damping of the elastic homogeneous coating and half-plane.Using the Helmholtz decomposition and Fourier integral transform technique,we derive the stresses and displacements of the coating and half-plane from Navier5s elasticdynamic equations in the form of complex integrals.Then,the global adaptive quadrature algorithm is exploited to solve the complex integrals numerically.The effects of Young’s modulus ratio,density ratio,coating thickness,loss factor and external excitation frequency are discussed.It is found that the dynamic response of displacements and stresses becomes increasingly oscillatory with the increase in excitation frequency.
