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The purpose of this paper is to construct a continuous time series model to study the thermal creep of rough surfaces in contact.

For normal loading, the contact between rough surfaces can often be modeled as the contact of an effective surface with a rigid fiat surface. A solution for the deformation of such equivalent surface, generated using fractal geometry, can be modified. However, in this study only the case of a single rough surface in contact with a rigid flat surface is considered. In the interface, the material is assumed to follow the idealized constitutive viscoelastic standard linear solid (SLS) model. Fractal geometry, through Cantor set theory, is utilized to model the roughness of the surface.

An asymptotic time series power law is obtained, which associates the creep load, the buck temperature and the creep of the fractal surface.

This law is only valid as long as the creep is of the size of the surface roughness. The modified model admits an analytical solution for the case when the behavior is linear viscoelastic. The proposed model shows a good agreement when compared with experimental results available in the literature.

The purpose of this paper is to develop a new finite difference method for solving the seismic wave propagation in fluid-solid media, which can be described by the acoustic and viscoelastic wave equations for the fluid and solid parts, respectively.

In this paper, the authors introduced a coordinate transformation method for seismic wave simulation method. In the new method, the irregular fluid–solid interface is transformed into a horizontal interface. Then, a multi-block coordinate transformation method is proposed to mesh every layer to curved grids and transforms every interface to horizontal interface. Meanwhile, a variable grid size is used in different regions according to the shape and the velocity within each region. Finally, a Lebedev-standard staggered coupled grid scheme for curved grids is applied in the multi-block coordinate transformation method to reduce the computational cost.

The instability in the auxiliary coordinate system caused by the standard staggered grid scheme is resolved using a curved grid viscoelastic wave field separation strategy. Several numerical examples are solved using this new method. It has been shown that the new method is stable, efficient and highly accurate in solving the seismic wave equation defined on domain with irregular fluid–solid interface.

First, the irregular fluid–solid interface is transformed into a horizontal interface by using the coordinate transformation method. The conversion between pressures and stresses is easy to implement and adaptive to different irregular fluid–solid interface models, because the normal stress and shear stress vanish when the normal angle is 90° in the interface. Moreover, in the new method, the strong false artificial boundary reflection and instability caused by ladder-shaped grid discretion are resolved as well.

The purpose of this paper is to develop a progressive damage framework to predict the fatigue life of cord-reinforced rubber composite under cyclic loadings. Special attention has been paid to failure mechanisms, like cord–rubber interfacial debonding, and rubber matrix damage.

The constitutive modeling is based on the continuum damage mechanics (CDMs) and the thermodynamics of irreversible process. The damage in rubber is described by an istropic law, whereas elasto-plastic continuum model has been proposed for cord–rubber interphase layer. The numerical framework is implemented into commercial finite element code Abaqus/Standard via user subroutine (UMAT).

One of the most important findings obtained from reviewing various techniques is that meso-level fatigue damage modeling based on developed framework can simulate competitive damage scenarios, e.g. debonding, delamination or matrix failure.

A systematic framework for predicting failure in cord-reinforced rubber composite is formulated within the context of CDMs that can also be applied for industrial components, such as tires and airsprings.

This study aims to analyse the behaviour of plane waves within a nonlocal transversely isotropic visco-thermoelastic medium having variable thermal conductivity.

The concept of enunciation is used in the generalized theory of thermoelasticity in accordance with the Green–Lindsay and Eringen’s nonlocal elasticity models. The linear viscoelasticity model developed by Kelvin–Voigt is used to characterize the viscoelastic properties of transversely isotropic materials.

It has been noticed that three plane waves, which are coupled together, travel through the medium at three different speeds. The derivation of reflection coefficients and energy ratios for reflected waves is carried out by incorporating suitable boundary conditions. Numerical computations are performed for the amplitude ratios, phase speeds and energy partition and displayed in graphical form.

The outcomes of the numerical simulation demonstrate that the amplitude ratios are significantly influenced by variable thermal conductivity, nonlocal parameters and viscosity. It is further observed from the plots that the phase speeds in a transversely isotropic medium depend on the angle of incidence. In addition, it has been established that the energy is preserved during the reflection phenomenon.

The finite element method (FEM) is used to calculate the two-dimensional anti-plane dynamic response of structure embedded in D’Alembert viscoelastic multilayered soil on the rigid bedrock. This paper aims to research a time-domain absorbing boundary condition (ABC), which should be imposed on the truncation boundary of the finite domain to represent the dynamic interaction between the truncated infinite domain and the finite domain.

A high-order ABC for scalar wave propagation in the D’Alembert viscoelastic multilayered media is proposed. A new operator separation method and the mode reduction are adopted to construct the time-domain ABC.

The derivation of the ABC is accurate for the single layer but less accurate for the multilayer. To achieve high accuracy, therefore, the distance from the truncation boundary to the region of interest can be zero for the single layer but need to be about 0.5 times of the total layer height of the infinite domain for the multilayer. Both single-layered and multilayered numerical examples verify that the accuracy of the ABC is almost the same for both cases of only using the modal number excited by dynamic load and using the full modal number of infinite domain. Using the ABC with reduced modes can not only reduce the computation cost but also be more friendly to the stability. Numerical examples demonstrate the superior properties of the proposed ABC with stability, high accuracy and remarkable coupling with the FEM.

A high-order time-domain ABC for scalar wave propagation in the D’Alembert viscoelastic multilayered media is proposed. The proposed ABC is suitable for both linear elastic and D’Alembert viscoelastic media, and it can be coupled seamlessly with the FEM. A new operator separation method combining mode reduction is presented with better stability than the existing methods.

This work aims at constructing a continuous mathematical, linear elastic, model for the thermal contact conductance (TCC) of two rough surfaces in contact.

The rough surfaces, known to be physical fractal, are modelled using a deterministic Cantor structure. Such structure shows several levels of imperfections and including, therefore, several scales in the constriction of the flux lines. The proposed model will study the effect of the deformation (approach) of the two rough surfaces on the TCC as a function of the remotely applied load.

An asymptotic power law, derived using approximate iterative relations, is used to express the area of contact and, consequently, the thermal conductance as a function of the applied load. The model is valid only when the approach of the two surface in contact is of the order of the surface roughness. The results obtained using this model, which admits closed form solution, are displayed graphically for selected values of the system parameters; the fractal surface roughness and various material properties. The obtained results showed good agreement with published experimental results both in trend and the numerical values.

The model obtained provides further insight into the effect that surface texture has on the heat conductance process. The proposed model could be used to conduct an analytical investigation of the thermal conductance of rough surfaces in contact. This model, although simple (composed of springs), nevertheless works well.

In this paper, special attention is focused on the study of the relaxation phenomena of fabrics containing elastane yarn.

For this purpose, the relaxation phenomena of wound fabric under constant deformation, as the consequence of accumulated stress during winding, were analysed. Maxwell's model and the modified standard linear solid model are used for explaining the relaxation.

The results of the study of the relaxation phenomena of fabrics containing elastane yarn show a close connection between stress relaxation under constant deformation in the fabric roll and the degree of deformation with manual unwinding. Expert knowledge of the relaxation phenomena in fabrics containing elastane yarns has a big influence on explaining the problem of dimensional changes and instability in such fabrics.

A better understanding of the relaxation phenomena in fabrics containing elastane yarns.

The purpose of this paper is to evaluate the effect that polymer coat has on the impact behavior of grinding sphere and to find possible subsection of parameter space in which grinding sphere wear could be reduced.

Numerical analysis is based on axisymmetric finite elements that were developed using symbolic tool AceGen. Comparing stress response of elastic and visco‐elastic material revealed that for high strain rates observed in impacts both behave the same and that is why elastic elements were used in simulations.

Impact velocity, coat thickness and polymer material properties were varied in a parametric case study of polymer‐coated sphere impact. Decrease of the pressure on the surface of grinding sphere indicates that polymer layer can be effective in reducing grinding media wear, but in order to maintain adequate impact pressure to do the grinding the impact velocity has to be increased. Both upper and lower limit for impact velocity were determined for some arbitrary pressure threshold values. This shows that combining measured threshold values of specific material with results from presented numerical tool could provide valuable guides for finding optimum stirred media milling operation parameters.

In this work, the authors develop numerical tools with the aim of supporting experimental development of polymer coat capable of reducing grinding media wear.

This study aims to present an architectural application of 4D-printed climate-adaptive kinetic architecture and parametric façade design.

This work investigates experimental prototyping of a reversibly self-shaping façade, by integrating the parametric design approach, smart material and 4D-printing techniques. Thermo-responsive building skin modules of two-way shape memory composite (TWSMC) was designed and fabricated, combining the shape memory alloy fibers (SMFs) and 3D-printed shape memory polymer matrices (SMPMs). For geometry design, deformation of the TWSMC was simulated with a dimension-reduced mathematical model, and an optimal arrangement of three different types of TWSMC modules were designed and fabricated into a physical scale model.

Model-based experiments show robust workability and formal reversibility of the developed façade. Potential utility of this module for adaptive building design and construction is discussed based on the results. Findings help better understand the shape memory phenomena and presented design-inclusive technology will benefit architectural communities of smart climate-adaptive building.

Two-way reversibility of 4D-printed composites is a topic of active research in material science but has not been clearly addressed in the practical context of architectural design, due to technical barriers. This research is the first architectural presentation of the whole design procedure, simulation and fabrication of the 4D-printed and parametrically movable façade.

The purpose of this paper is to analyze the stress‐relaxation behavior of different woven fabrics under constant torsional strain in a wrinkled state. For this purpose, a new method for determination of stress‐relaxation behavior of the fabric was used while keeping the torsional strain constant.

In this study, the behavior of stress relaxation of fabric is examined with modification of wrinkle force tester sophisticated electro‐mechanical method and fabricating a device which uses a computer and micro controller, with constant torsional strain by a rotational level of 9.1 turn/m in 280°, and in 300 s.

The results depict that stress‐relaxation percentage in fabric in weft alignment is more than warp alignment and the fabrics which tolerate more torsional force, possess less stress‐relaxation percentages. In this way, with increasing polyester percentage in fabric the scale of stress‐relaxation percentage decreases. Also, adoption of data derived from experiments with Maxwell model shows that the interlaced model is a suitable model for explaining the stress relaxation decline in fabric. Correlation coefficient of fabrics in weft alignment with Maxwell model is more than warp alignment.

This study has practical implications in the clothing as well as in technical textiles areas.

Knowing visco‐elastic properties is very important. However, there is no information available to study the stress relaxation of woven fabrics under the combined influences of compression and constant torsional strains.