This paper investigates the adhesive nanocontact behavior of an elastic halfplane indented by a rigid cylindrical indenter,incorporating the simultaneous effects of surface elasticity,couple stresses,and adhesion.The ...This paper investigates the adhesive nanocontact behavior of an elastic halfplane indented by a rigid cylindrical indenter,incorporating the simultaneous effects of surface elasticity,couple stresses,and adhesion.The free surface of the half-plane is modeled by the Steigmann-Ogden surface elasticity theory,while the bulk material behavior is described by the classical couple-stress elasticity theory.The adhesion at the contact interface is characterized by the Maugis-Dugdale(MD)adhesive contact model.Building on the fundamental nonclassical Flamant solution,the governing equations and boundary conditions of the nanocontact problem are reformulated into a system of triple integral equations.These equations are solved numerically by the Gauss-Chebyshev quadratures in combination with an iterative algorithm.The validation against the existing literature confirms the accuracy and robustness of the proposed solution methodology.Comprehensive parametric studies are performed to elucidate the critical roles of surface elasticity and couple stresses in adhesive nanocontact.The numerical results provide insights into the complex interactions among surface,couple-stress,and adhesive effects.Specifically,the interplay between the surface and adhesive effects is predominantly competitive,while the interaction between the couple stresses and adhesion exhibits an intricate nature.The findings highlight the necessity of simultaneously considering surface elasticity,couple stresses,and adhesion in nanoindentation analyses to achieve accurate predictions of material responses.展开更多
The problem of a periodic array of parallel cracks in a homogeneous piezoelectric strip bonded to a functionally graded piezoelectric material is investigated for inhomogeneous continuum. It is assumed that the materi...The problem of a periodic array of parallel cracks in a homogeneous piezoelectric strip bonded to a functionally graded piezoelectric material is investigated for inhomogeneous continuum. It is assumed that the material inhomogeneity is represented as the spatial variation of the shear modulus in the form of an exponential function along the direction of cracks. The mixed boundary value problem is reduced to a singular integral equation by applying the Fourier transform, and the singular integral equation is solved numerically by using the Gauss-Chebyshev integration technique. Numerical results are obtained to illustrate the variations of the stress intensity factors as a function of the crack periodicity for different values of the material inhomogeneity.展开更多
基于声学边界元基本理论,并结合Chebyshev谱方法进行了声散射数值计算研究.采用2阶边界单元,谱点离散选用不包含边界的CG(Chebyshev-Gauss)配点法,克服了传统边界元在表面单元节点处出现的法向及法向导数不连续的现象;应用CHIEF(Combine...基于声学边界元基本理论,并结合Chebyshev谱方法进行了声散射数值计算研究.采用2阶边界单元,谱点离散选用不包含边界的CG(Chebyshev-Gauss)配点法,克服了传统边界元在表面单元节点处出现的法向及法向导数不连续的现象;应用CHIEF(Combined Helmholtz Integral Equation Fomulation)方法进行了数值非唯一性处理,提高了计算的精度.与传统边界元方法进行了精度和效率的对比分析,证明该方法具有计算快速、精度高的特点.展开更多
基金Project supported by the National Natural Science Foundation of China(No.12072072)。
文摘This paper investigates the adhesive nanocontact behavior of an elastic halfplane indented by a rigid cylindrical indenter,incorporating the simultaneous effects of surface elasticity,couple stresses,and adhesion.The free surface of the half-plane is modeled by the Steigmann-Ogden surface elasticity theory,while the bulk material behavior is described by the classical couple-stress elasticity theory.The adhesion at the contact interface is characterized by the Maugis-Dugdale(MD)adhesive contact model.Building on the fundamental nonclassical Flamant solution,the governing equations and boundary conditions of the nanocontact problem are reformulated into a system of triple integral equations.These equations are solved numerically by the Gauss-Chebyshev quadratures in combination with an iterative algorithm.The validation against the existing literature confirms the accuracy and robustness of the proposed solution methodology.Comprehensive parametric studies are performed to elucidate the critical roles of surface elasticity and couple stresses in adhesive nanocontact.The numerical results provide insights into the complex interactions among surface,couple-stress,and adhesive effects.Specifically,the interplay between the surface and adhesive effects is predominantly competitive,while the interaction between the couple stresses and adhesion exhibits an intricate nature.The findings highlight the necessity of simultaneously considering surface elasticity,couple stresses,and adhesion in nanoindentation analyses to achieve accurate predictions of material responses.
基金Project supported by the National Natural Science Foundation of China(No.10661009)the Ningxia Natural Science Foundation(No.NZ0604).
文摘The problem of a periodic array of parallel cracks in a homogeneous piezoelectric strip bonded to a functionally graded piezoelectric material is investigated for inhomogeneous continuum. It is assumed that the material inhomogeneity is represented as the spatial variation of the shear modulus in the form of an exponential function along the direction of cracks. The mixed boundary value problem is reduced to a singular integral equation by applying the Fourier transform, and the singular integral equation is solved numerically by using the Gauss-Chebyshev integration technique. Numerical results are obtained to illustrate the variations of the stress intensity factors as a function of the crack periodicity for different values of the material inhomogeneity.
文摘基于声学边界元基本理论,并结合Chebyshev谱方法进行了声散射数值计算研究.采用2阶边界单元,谱点离散选用不包含边界的CG(Chebyshev-Gauss)配点法,克服了传统边界元在表面单元节点处出现的法向及法向导数不连续的现象;应用CHIEF(Combined Helmholtz Integral Equation Fomulation)方法进行了数值非唯一性处理,提高了计算的精度.与传统边界元方法进行了精度和效率的对比分析,证明该方法具有计算快速、精度高的特点.
