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This paper aims at the problem of surrounding rock excavation damage zone of tunneling in the rich water region, this paper aims to propose a new seepage-stress-damage coupling model and studied the numerical algorithm. This reflects the characteristics of rock damage evolution, accompanied by plastic flow deformation and multi-field interaction.

First of all, rock elastoplastic damage constitutive model based on the Drucker–Prager criterion is established, the fully implicit return mapping algorithm is adopted to realize the numerical solution. Second, based on the relation between damage variation and permeability coefficient, the rock stress-seepage-damage model and multi-field coupling solving iterative method are presented. Finally, using the C++ language compiled the corresponding programs and simulated tunnel engineering in the rich water region.

Results show that difference evolution-based back analysis inversed damage parameters well, at the same time the established coupling model and calculating program have more advantages than general conventional methods. Multiple field coupling effects should be more considered for the design of tunnel support.

The proposed method provides an effective numerical simulation method for the construction of the tunnel and other geotechnical engineering involved underground water problems.

The advanced synthetic and natural materials, such as piezoelectric ceramics, electroactive polymers and biological soft tissues, exhibit the multi‐physical or physicochemical coupling behaviors. The coupling behavior involves the thermal‐mechanical, electric‐mechanical and electrochemicalmechanical interactions. The coupling phenomena can be modeled in the microscopic and macroscopic levels. In the microscale, the material consists of the solid, fluid and ions. The domain FE technique can be used to model the deformation of the solid and the flow of the fluid. In the macroscale, the mixture theory can be applied to description of the coupled response of the continuum under coupled thermal, electrical, chemical and mechanical loadings. A weak form of the governing equations is established by means of variational principle and a multi‐field finite element (MFE) method is developed for numerical modeling of the coupling behavior of advanced materials.

The purpose of this paper is to investigate the numerical fluid-structure interaction (FSI) framework for the simulations of mechanical behavior of new vortex generators (VGs) in smooth wavy fin-and-elliptical tube (SWFET) heat exchanger using the ANSYS MFX Multi-field® solver.

A three-dimensional FSI approach is proposed in this paper to provide better understanding of the performance of the VG structures in SWFET heat exchangers associated with the alloy material properties and geometric factors. The Reynolds-averaged Navier-Stokes equations with shear stress transport turbulence model are applied for modeling of the turbulent flow in SWFET heat exchanger and the linear elastic Cauchy-Navier model is solved for the structural von Mises stress and elastic strain analysis in the VGs region.

Parametric studies conducted in the course of this research successfully identified illustrate that the maximum magnitude of von Mises stress and elastic strain occurs at the root of the VGs and depends on geometrical parameters and material types. These results reveal that the titanium alloy VGs shows a slightly higher strength and lower elastic strain compared to the aluminum alloy VGs.

This paper is one of the first in the literature that provides original information mechanical behavior of a SWFET heat exchanger model with new VGs in the field of FSI coupling technique.

Continua and discontinua coexist in natural rock materials. This paper aims to present an improved approach for addressing the mechanical response of rock masses based on the combined finite-discrete element method (FDEM) proposed by Munjiza.

Several algorithms have been programmed in the new approach. The algorithms include (1) a simpler and more efficient algorithm to calculate the contact force; (2) An algorithm for tangential contact force closer to the actual physical process; (3) a plastic yielding criterion (e.g. Mohr-Coulomb) to modify the elastic stress for fitting the mechanical behavior of elastoplastic materials; and (4) a complete code for the mechanical calculation to be implemented in Matrix Laboratory (MATLAB).

Three case studies, including two standard laboratory experiments (uniaxial compression and Brazilian split test) and one engineering-scale anti-dip slop model, are presented to illustrate the feasibility of the Y-Mat code and its ability to deal with multi-scale rock mechanics problems. The results, including the progressive failure process, failure mode and trajectory of each case, are acceptable compared to other corresponding studies. It is shown that, the code is capable of modeling geotechnical and geological engineering problems.

This article gives an improved FDEM-based numerical calculation code. And, feasibility of the code is verified through three cases. It can effectively solve the geotechnical and geological engineering problems.

The purpose of this article is to understand the current research status and future development trends in the field of numerical simulation on rock mass grouting.

This article first searched the literature database (EI, Web of Science, CNKI, etc.) for keywords related to the numerical simulation of rock mass grouting to obtain the initial literature database. Then, from the initial database, several documents with strong relevance to the numerical simulation theme of rock mass grouting and high citation rate were selected; some documents from the references were selected as supplements, forming the sample database of this review study (a total of 90 articles). Finally, through sorting out the relationship among the literature, this literature review was carried out.

The numerical simulation of rock mass grouting is mainly based on the porous media model and the fractured media model. It has experienced the development process from Newtonian fluid to non-Newtonian fluid, from time-invariant viscosity to time-varying viscosity, and from generalized theoretical model to engineering application model. Based on this, this article summarizes four scientific problems that need to be solved in the future in this research field: the law of grout distribution at the cross fissures, the grout diffusion mechanism under multi-field coupling, more accurate grouting theoretical model and simulation technology with strong engineering applicability.

This research systematically analyzes the current research status and shortcomings of numerical simulation on rock mass grouting, summarizes four key issues in the future development of this research field and provides new ideas for the future research on numerical simulation on rock mass grouting.

The purpose of this paper is to perform the thermo-hydro-mechanical (THM) numerical analysis in order to study the thawing process for frozen soil and to predict the thawing settlement.

A new one-dimensional multi-field physical coupled model was proposed here to describe the thawing process of saturated frozen soil, whereby the void ratio varied linearly with effective stress (Eq. 10) and hydraulic conductivity (Eq. 27b). The thawing process was simulated with different initial and boundary conditions in an open system with temperature variations. The mechanical behavior and water migration of the representative cases were also investigated.

The comparisons of representative cases with experimental data demonstrated that the model predicts thawing settlement well. It was found that the larger temperature gradient, higher overburden pressure and higher water content could lead to larger thawing settlement. The temperature was observed that to distribute height linearly in both frozen zone and unfrozen zone of the sample. Water migration forced to a decrease in the water content of the unfrozen zone and an increase in water content at the thawing front.

In this study, only the one-directional thawing processes along the frozen soil samples were investigated numerically and compared with test results, which can be extended to two-dimensional analysis of thawing process in frozen soil.

This study helps to understand the thawing process of frozen soil by coupled thermo-hydro-mechanical numerical simulation.

This paper aims to present a method based on dynamics to find the transient pressure at the nozzle area of a piezoelectric inkjet printer. This pressure responds to input signals of the piezoelectric driver deformation. The pressure at the nozzle is the boundary condition of the computational fluid dynamics model of the inkjet printer nozzle, and serves as the “bridge” between the piezoelectric driver actuation and the droplet generation of an inkjet printer.

The transient pressure was estimated using a fluid-solid coupling numerical model of the printerhead. In this study, a simple step-shape signal was applied. The printerhead chamber was considered to act as a linear Helmholtz resonator to determine the system transfer function between the input of driver deformation and the output of pressure. By decomposing the input signal into several simple signals, the transient pressure is the superposition of those calculated pressures.

The pressure values determined by transfer function and by superposition match the pressure values directly calculated by a fluid-solid coupling model. This demonstrates the rationality and practicability of the method.

This paper proposes a method to identify a proper boundary condition of pressure for numerical models that only include the fluid field around the nozzle. This strategy eliminates the need to calculate the complex and unstable fluid-solid coupling for every pattern of input. Additionally, the suitable boundary condition of transient pressure can be set rather than relying on the shape of the PZT driver deformation signal.

Electromagnetic noise of permanent magnet synchronous motor (PMSM) seriously affects the sound quality of electric vehicles (EVs). This paper aims to present a comprehensive process for the electromagnetic noise analysis and optimization of a water-cooled PMSM.

First, the noises of an eight-pole 48-slot PMSM in at speeds up to 10,000 rpm are measured. Furthermore, an electromagnetic-structural-acoustic model of the PMSM is established for multi-field coupling simulations of electromagnetic noises. Finally, the electromagnetic noise of the PMSM is optimized by using the multi-objective genetic algorithm, where a multi-objective function related to the slot width of PMSM stator is defined for radial electromagnetic force (REF) optimization.

The experimental results show that main electromagnetic noises are the 8n-order (n = 1, 2, 3, …) and 12-order noises. The simulated results show that the REFs are mainly generated by the 8n-order (n = 1, 2, 3, 4, 5, 6) vibrations, especially those of the 8th, 16th, 24th and 32th orders. The 12-order noise is a mechanical noise, which might be caused by the bearings and other structures of the PMSM. Comparing the simulated results before and after optimization, both the REFs and electromagnetic noises are effectively reduced, which suggests that an appropriate design of stator slot is important for reducing electromagnetic noise of the PMSM.

In view of applications, the methods proposed in this paper can be applied to other types of PMSM for generation mechanism analysis of electromagnetic noise, optimal design of PMSM and thereby noise improvement of EVs.

This paper aims to establish the mathematical model and solve the complex calculation multi-field coupling problem for an electromagnetic overhead transmission line galloping excitation test system.

An electromagnetic excitation test system is introduced. To calculate the vibration response of the transmission line, a transient coupled finite element model containing electromagnetic repulsive mechanism and transmission line system was established. Considering the advantages of Newmark-ß algorithm and fourth-order Runge–Kutta algorithm, the two algorithms are combined to solve the model. Compared with the simulation results of existing commercial finite element software, the accuracy of the calculation model of electromagnetic force and wire vibration response are verified.

Comparison results show that the proposed calculation model can accurately obtain the force of electromagnetic mechanism and the vibration response of the overhead power lines, and improve the calculation efficiency. The calculation results show that vibration under electromagnetic excitation presents a double half-wave mode, and the galloping amplitude varies according to the charging voltage.

This paper built the transient simulation model for a galloping test system. The Newmark-ß algorithm and the fourth-order Runge–Kutta algorithm are used to solve the model. The research results are of great significance for the actual galloping test system design.

In high-pressure pumps, due to the interaction of asperities on the upper and lower surfaces, the piston–cylinder interface suffers severe lubrication and sealing problems during mixed lubrication. This study aims to establish a mixed thermo-elastohydrodynamic (EHD) model for the lubrication gap to determine how working conditions affect the lubricating characteristics and sealing performance of the interface.

A mixed thermo-EHD lubrication model is established to investigate the lubricating characteristics and sealing performance of the interface between the piston and cylinder. The model considers piston tilting, thermal effect, surface roughness and bushing deformation. The interface lubricating characteristics and sealing performance under different working conditions are calculated by the proposed numerical model.

A higher inlet pressure contributes to an increase in the minimum film thickness. Increased shaft speed can significantly reduce the minimum film thickness, resulting in severe wear. Compared to roughness, the impact of the thermal effect on the interface sealing performance is more significant.

The proposed lubrication model in this study offers a theoretical framework to evaluate the lubricating characteristics and sealing performance at the lubrication gap. Furthermore, the results provide references for properly selecting piston-cylinder surface processing parameters.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2023-0072/