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It is well known that stress singularity may exist at the edges of a bonded bi‐material interface due to the discontinuity of material properties. This stress singularity causes difficulty in accurately determining the bi‐material interface bonding strength. This paper aims to present a new design of specimen geometry to eliminate the stress singularity and present an experimental procedure to more accurately determine the bonding strength of the bi‐material interface.

The design is based on an asymptotic analysis of the stress field near the free edge of bi‐material interface. The critical bonding angle, which delineates the singular and non‐singular stress field near the free edge, is determined.

With the new designed specimen and a special iterative calculation algorithm, the interface bonding strength envelope of an epoxy‐aluminum interface was experimentally determined.

This new design of specimen, experimental procedure and iterative algorithm may be applied to obtain more reasonable and accurate bonding strength data for a wide range of bi‐material interfaces.

The purpose of this paper is to address the problems of interaction of tensile stress-waves with polyurea/fused-silica and fused-silica/polyurea interfaces, and the potential for the accompanying interfacial decohesion.

The problems are investigated using all-atom non-equilibrium molecular-dynamics methods and tools. Before these methods/tools are employed, previously determined material constitutive relations for polyurea and fused-silica are used, within an acoustic-impedance-matching procedure, to predict the outcome of the interactions of stress-waves with the material-interfaces in question. These predictions pertain solely to the stress-wave/interface interaction aspects resulting in the formation of transmitted and reflected stress- or release-waves, but do not contain any information regarding potential interfacial decohesion. Direct molecular-level simulations confirmed some of these predictions, but also provided direct evidence of the nature and the extent of interfacial decohesion. To properly model the initial state of interfacial cohesion and its degradation during stress-wave-loading, reactive forcefield potentials are utilized.

Direct molecular-level simulations of the polyurea/fused-silica interfacial regions prior to loading revealed local changes in the bonding structure, suggesting the formation of an interphase. This interphase was subsequently found to greatly affect the polyurea/fused-silica decohesion strength.

To the authors’ knowledge, the present work is the first public-domain report of the use of the non-equilibrium molecular dynamics and reactive force-field potentials to study the problem of interfacial decohesion caused by the interaction of tensile waves with material interfaces.

Contact problems are among the most difficult ones in mechanics. Due to its practical importance, the problem has been receiving extensive research work over the years. The finite element method has been widely used to solve contact problems with various grades of complexity. Great progress has been made on both theoretical studies and engineering applications. This paper reviews some of the main developments in contact theories and finite element solution techniques for static contact problems. Classical and variational formulations of the problem are first given and then finite element solution techniques are reviewed. Available constraint methods, friction laws and contact searching algorithms are also briefly described. At the end of the paper, a bibliography is included, listing about seven hundred papers which are related to static contact problems and have been published in various journals and conference proceedings from 1976.

The purpose of this paper is to compute the stress intensity factors (SIFs) of single edge interface crack for arbitrary material combinations and various relative crack lengths, and compare with those for the bonded plates subjected to tensile loading conditions. It aims to discuss the results of the shallow edge interface crack on the basis of the singular stress near the free‐edge corner without the crack.

In this study, the SIFs of interface crack in dissimilar bonded plates subjected to bending loading conditions are analyzed by the finite element method and a post‐processing technique. The use of post‐processing technique of extrapolation reduces the computational cost and improves the accuracy of the obtained result.

The empirical expressions are proposed for evaluating the SIFs of arbitrary material combinations.

Empirical functions can be used to obtain the SIFs for arbitrary material combinations for the bending loading conditions easily. It is very convenient for engineering application.

The purpose of this paper is to achieve numerical simulation of discontinuous rock masses.

The extended finite element method (XFEM) was used. Discontinuities (such as joints, faults, and material interfaces) are contained in the elements, thus the mesh can be generated without taking into account the existence of discontinuities. When one element contains no discontinuity, the displacement function is degenerated into that of the conventional finite element. For the element containing discontinuities, the standard displacement‐based approximation is enriched by incorporating level‐set‐based enrichment functions that model the discontinuities, and an element subdivision procedure is used to integrate the domain of the element.

Mesh generation can be simplified considerably and high‐quality meshes can be obtained. A solution with good precision can also be achieved. It is concluded that the XFEM technique is especially suitable in simulating discontinuous rock masses problems.

Crack initiation and propagation should be considered in further studies.

The paper presents a very useful numerical method for a geotechnical engineering problem that has the ability to simulate the failure process of discontinuous rock masses. The method is expected to be used widely in the deformation and stability analysis of complicated rock masses.

The paper provides a new numerical method for discontinuous rock masses that is very convenient for pre‐processing.

The purpose of this paper is to study the mechanical response of polyurea, soda-lime glass (glass, for short), polyurea/glass/polyurea and glass/polyurea/glass sandwich structures under dynamic-loading conditions involving propagation of planar longitudinal shockwaves.

The problem of shockwave generation, propagation and interaction with material boundaries is investigated using non-equilibrium molecular dynamics. The results obtained are used to construct basic shock Hugoniot relationships associated with the propagation of shockwaves through a homogeneous material (polyurea or glass, in the present case). The fidelity of these relations is established by comparing them with their experimental counterparts, and the observed differences are rationalized in terms of the microstructural changes experienced by the shockwave-swept material. The relationships are subsequently used to predict the outcome of the interactions of shockwaves with polyurea/glass or glass/polyurea material boundaries. Molecular-level simulations are next used to directly analyze the same shockwave/material-boundary interactions.

The molecular-level simulations suggested, and the subsequent detailed microstructural analyses confirmed, the formation of topologically altered interfacial regions, i.e. polyurea/glass and glass/polyurea interphases.

To the authors’ knowledge, the present work is a first attempt to analyze, using molecular-level simulation methods, the interaction of shockwaves with material boundaries.

The purpose of this paper is as follows: to significantly reduce the computation time (by a factor of 1,000 and more) compared to known numerical techniques for real-world problems with complex interfaces; and to simplify the solution by using trivial unfitted Cartesian meshes (no need in complicated mesh generators for complex geometry).

This study extends the recently developed optimal local truncation error method (OLTEM) for the Poisson equation with constant coefficients to a much more general case of discontinuous coefficients that can be applied to domains with different material properties (e.g. different inclusions, multi-material structural components, etc.). This study develops OLTEM using compact 9-point and 25-point stencils that are similar to those for linear and quadratic finite elements. In contrast to finite elements and other known numerical techniques for interface problems with conformed and unfitted meshes, OLTEM with 9-point and 25-point stencils and unfitted Cartesian meshes provides the 3-rd and 11-th order of accuracy for irregular interfaces, respectively; i.e. a huge increase in accuracy by eight orders for the new 'quadratic' elements compared to known techniques at similar computational costs. There are no unknowns on interfaces between different materials; the structure of the global discrete system is the same for homogeneous and heterogeneous materials (the difference in the values of the stencil coefficients). The calculation of the unknown stencil coefficients is based on the minimization of the local truncation error of the stencil equations and yields the optimal order of accuracy of OLTEM at a given stencil width. The numerical results with irregular interfaces show that at the same number of degrees of freedom, OLTEM with the 9-points stencils is even more accurate than the 4-th order finite elements; OLTEM with the 25-points stencils is much more accurate than the 7-th order finite elements with much wider stencils and conformed meshes.

The significant increase in accuracy for OLTEM by one order for 'linear' elements and by 8 orders for 'quadratic' elements compared to that for known techniques. This will lead to a huge reduction in the computation time for the problems with complex irregular interfaces. The use of trivial unfitted Cartesian meshes significantly simplifies the solution and reduces the time for the data preparation (no need in complicated mesh generators for complex geometry).

It has been never seen in the literature such a huge increase in accuracy for the proposed technique compared to existing methods. Due to a high accuracy, the proposed technique will allow the direct solution of multiscale problems without the scale separation.

The small dimensions of future device designs also imply a stronger effect of material boundary resistance. For nanoscale devices and structures, especially, interface phenomena often dominate their overall thermal behavior. The purpose of this paper is to propose molecular dynamics (MD) simulations to investigate the mechanical and thermal properties at Cu‐Al interface.

The two‐temperature model (TTM)‐MD model is used to describe the electron‐phonon scattering at interface of different metals. Before the simulation of heat transfer process, a non‐ideal Cu‐Al interface is constructed by simulating diffusion bonding.

According to the simulation results, in unsteady state, the temperature distribution and the displacements of atoms near the interface tend to generate stress and voids. It reveals the damage mechanics at the interface in heat transfer.

The atomic model proposed in this paper is computationally efficient for interfacial heat transfer problems, and could be used for investigation of other interfacial behaviors of dissimilar materials.

The purpose of this paper is to evaluate theoretically and numerically the stress and stress intensity factor (SIF) at the time of propagation of the crack in bi-material. The problem is formulated using two thin materials which are bound by a cracked adhesive at the tip and having a micro-crack in one of these two materials.

The plane stresses and the SIF will be determined as a function of two parameters (Poisson’s ratio and Shear modulus). The numerical analysis is carried out on a flat element, having a main crack in one of these ends, and a micro-crack varies in the vicinity of this main crack. The problem is analyzed by the finite element method and processed by computational software (ABAQUS).

The numerical and theoretical analysis allowed the author to determine and compare the values of plane stresses and SIF in each area of the material.

The theoretical analysis of SIF is based mainly on a mathematical calculation of equations of plane stresses; these equations are determined by development of complex analytical functions of bi-materials given by other researchers. Using the numerical method, several models are modeled by changing the micro-crack position relative to the main crack to determine the plane stresses and SIF for each position.

The purpose of this paper is to solve the local problem involving strong contrast heterogeneous conductive material, with application to gas-filled porous media with both perfect and imperfect Kapitza boundary conditions at the bi-material interface. The effective parameters like the dynamic conductivity and the thermal permeability in the acoustics of porous media are also derived from the cell solution.

The Fourier transform method is used to solve frequency-dependent heat transfer problems. The periodic Lippmann–Schwinger integral equation in Fourier space with source term is first formulated using discrete Green operators and modified wavevectors, which can then be solved by iteration schemes.

Numerical examples show that the schemes converge fast and yield accurate results when compared with analytical solution for benchmark problems.

The formulation of the method is constructed using static and dynamic Green operators and can be applied to pixelized microstructure issued from tomography images.