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The calculation of the crack width is necessary for the design of prestressed concrete (PC) members. The purpose of this paper is to develop a numerical model based on the bond-slip theory to calculate the crack width in PC beams.

Stress calculation method for common reinforcement after beam crack has occurred depends on the difference in the bonding performance between prestressed reinforcement and common reinforcement. A numerical calculation model for determining the crack width in PC beams is developed based on the bond-slip theory, and verified using experimental data. The calculation values obtained by the proposed numerical model and code formulas are compared, and the applicability of the numerical model is evaluated.

The theoretical analysis and experimental results verified that the crack width of PC members calculated based on the bond-slip theory in this study is reasonable. Furthermore, the stress calculation method for the common reinforcement is verified. Compared with the model calculation results obtained in this study, the results obtained from code formulas are more conservative.

The numerical calculation model for crack width proposed in this study can be used by engineers as a reference for calculating the crack width in PC beams to ensure the durability of the PC member.

The purpose of this paper is to present the differences in results of numerical calculations arising from different simplifications of the rotational magnetization model in typical dynamo sheets.

A comprehensive model of rotational magnetization processes in typical dynamo sheets should take into consideration the magnetic hysteresis and eddy current phenomena and also certain anisotropic properties. The chosen model of the rotational magnetization is briefly presented in this paper. A method of the inclusion of the rotational magnetization model into equations of the magnetic field distribution is described. The correctness of these equations has been verified experimentally. Numerical calculations of the rotational magnetization in two types of dynamo sheets were carried out for several simplifications of the described model.

Results of numerical calculations of the rotational magnetization with the omission of the hysteresis phenomenon or with the omission of eddy currents were compared with results obtained with the use of the comprehensive model of the rotational magnetization.

The paper presents comments and recommendations concerning the omission of both the hysteresis phenomenon and eddy currents in the analysis of the rotational magnetization in dynamo sheets and the impact of these simplifications on numerical calculation results.

The content of the paper refers to very important issues of modeling and calculations of the rotational magnetization in typical dynamo steel sheets.

The purpose of this paper is to formulate and simulate the interaction between particles and fields for gyroklystron amplifier rapidly and effectively.

From Maxwell's equations, transient electromagnetic field equations and particle motion equations, as the subject of a self‐consistent field theory, are obtained by semi‐analytical and semi‐numerical method. A numerical calculation model on the interaction between particles and fields is proposed and illustrated in detail. Based on above‐mentioned field theory, calculation model and the Runge‐Kutta method, a program to simulate the interaction between particles and fields is designed and its software implementation is achieved using Fortran language. To testify the correctness of the calculation model, a millimeter wave gyroklystron amplifier is simulated by the program, and some numerical results are presented and analyzed. Meanwhile, a contrast among the simulated frequency characteristic, the FDTD‐PIC results and the experiments is made. The computing resources needed by the program are compared with that needed by the FDTD‐PIC method.

The calculation results show that the model and the program take less CPU time and fewer computing resources than FDTD‐PIC simulation. Moreover, simulated results are in accord with the FDTD‐PIC results and the experiments.

A calculation model on the interaction between particles and fields is proposed and achieved in this paper. A program is designed and proved to be a fast and effective calculation tool for solving the simulation of the interaction. In addition, a detailed speed spread model of particles is studied. The calculation model considering speed spread, the program and the simulated results constitute the main contribution of this paper.

A mathematical gas dynamic model for semiconductor devices is numerically analysed. The well‐known ballistic diode problem is taken as an example.

This paper aims to focus on three-dimensional (3D) numerical simulation of a monitored urban underground road consisting of diaphragm walls supported by one row of temporary steel struts and a cover slab in the central area. In addition to the lateral wall displacements, the analysis focuses on the load development in the struts and the evolution of the total stresses at the soil–wall interface, and highlights the 3D effect on the behavior of the structure.

Computation by back-analysis has become an important contribution to the understanding of observed phenomena. In this context, this paper investigates a full 3D numerical back-analysis of diaphragm wall deformation using the finite difference code FLAC3D.

The instrumentation allows a deep understanding of the ground response and the soil-structure interaction phenomena. It also provides an opportunity to validate numerical models. Using a soil model with simple failure criteria, the wall displacements are strongly influenced by the soil deformation modulus. The strut stiffness considerably influences the wall behavior. The geometrical effects have a significant impact on the induced wall displacements.

In the present study, the main soil geotechnical characteristics were deduced from laboratory and in situ tests. However, Young’s modulus of the soil has been adjusted to take account of the unloading effect. In the same context, the non-linearity of the elastic characteristics of the steel struts has been taken into account by modeling the struts using their experimental stiffness instead of their theoretical rigidity.

In this paper, some issues about model formulation and solving methods for the Lorenz’s model are discussed, which also deals with fundamental characteristics of non‐linear models. Mainly, there existed problems that Lorenz’s model was formulated based on the weak nonlinear, and spectral expansion which changed the fundamental properties of prototype of the N‐S equations. Furthermore, its solving methods, which are based on continuously smoothing schemes, not only distorted the fundamental characteristics of non‐linear models, but also led to misunderstanding of the concept of “schaos”, which has already caused confusion to people’s way of thinking. In essence, Lorenz’s chaos is an “error volute” which is trapped into “calculation of error values”. Whether it can be named “chaos” may need to be discussed with questions.

In the present study, a finite volume approach for solving two‐dimensional, two‐fluids flows with heat and mass transfer was developed for predicting the flow of particulate materials through pneumatic dryer. The model was solved for a two‐dimensional steady‐state condition and considering axial and radial profiles for the flow variables. A two‐stage drying process was implemented. The numerical procedure includes discretization of calculation domain into torus‐shaped final volumes, solving the gas phase conservation equations by a modified semi‐implicit method for pressure‐linked equations algorithm, and the conservation equations of particulate phase were solved by the explicit forward difference algorithm. The mass momentum and energy coupling between the phases were considered by principles of the Interphase slip algorithm. In order to validate the theoretical and the numerical models, the developed models were applied to simulate the drying process of wet PVC particles in a large‐scale pneumatic dryer and to the drying process of wet sand in a laboratory‐scale pneumatic dryer. The predictions of the numerical simulations were compared successfully with the results of independent numerical and experimental investigations. Following the models validation, the two‐dimensional distributions of the flow characteristics were examined.

The purpose of this paper is to establish a rapid and effective numerical model of thin film lubrication with clear physical conception, in which viscosity variation along the direction of film thickness was used instead of average viscosity, and continuous Reynolds equation was used in the calculation of thin film lubrication.

Based on rheology and thin film lubrication with point contact and considering features of shear thinning and like-solidification of lubricant oil in the thin film lubrication state, a modified formula with overall average equivalent viscosity was proposed by combining numerical calculation and experiment data.

It is a fast and efficient method for film lubrication state simulation.

Thin film lubrication research on a nanoscale is very popular, and a variety of thin film lubrication models are proposed. Due to the complexity of thin film lubrication, it is still in the stage of revealing law and establishing calculation model.

The key issue is how to obtain the viscosity correction formula derived from engineering practice, also considered the lubricating oil class solidification and shear-thinning properties on thin film lubrication, while based on the system experiment, the viscosity modified formula for the gap, speed changes are proposed to obtain the overall average equivalent viscosity which makes the thin film lubrication micro to macro, so that a clear physical meaning for thin-film lubrication numerical calculation model is established.

This paper aims to describe and investigate the mathematical models and numerical modeling of how a cell membrane is affected by a transient ice freezing front combined with the influence of thermal fluctuations and anisotropy.

The study consists of mathematical modeling, validation with an analytical solution, and shows the influence of thermal noises on phase front dynamics and how it influences the freezing process of a single red blood cell. The numerical calculation has been modeled in the framework of the phase field method with a Cahn–Hilliard formulation of a free energy functional.

The results show an influence scale on directional phase front propagation dynamics and how significant are stochastic thermal noises in micro-scale freezing.

The numerical calculation has modeled in the framework of the phase field method with a Cahn–Hilliard formulation of a free energy functional.

The case-study building of this work is the Medieval Inn of Gralheira (“Pousada Medieval da Gralheira”) located in Vila Pouca de Aguiar, Portugal. This building is an example of the structures of that time, located in Trás-os-Montes, Portugal. A large amount of the built heritage suffers from advanced degradation, making the recovery, increasing the complexity of the rehabilitation and restoration intervention and implying a highly specialized interdisciplinary component. Therefore, the purpose of this paper is to carry out a study of the building in order to perform an analysis of its wood floor and assess its structural behaviour and conservation status. This work also presents some examples of intervention methods and rehabilitation techniques used to solve problems in the masonry structure and wood structures.

In this work, a numerical model of a wood pavement of a medieval building is presented, which was developed and calibrated with values obtained in an experimental campaign of wood specimens extracted from the floor structure and the deformation measured in situ. This model aims to analyse and predict the behaviour of the structure in terms of serviceability limit states. Rehabilitation and reinforcing techniques are described, for specific damages, complemented with a critical comparative analysis to define the most appropriate rehabilitation measures for each situation.

In this work, for the numerical model of the medieval building under consideration, the support of the beams in the walls between 50 per cent embedded and simply supported (hinge supports) was used. Since the beams have some restriction imposed by the wall, they have a delivery about 20 cm in the wall. The consideration of the delivery between beam and columns as simply supported (hinge supports) is a reasonable approximation. There is a difference between the values of deformation obtained in the numerical model and in situ due to the support conditions and also due to the consideration of the pavement loads as a distributed load, which does not correspond entirely to reality, since the pavement confers rigidity to the floor, behaving like a diaphragm. The presented intervention techniques are not applicable in all structures because each building has different characteristics, in terms of materials and construction. The pathologies occur due to many sources and each case is unique, and must be carefully studied before taking decisions about the rehabilitation methods to use.

This work presents a numerical model of wood pavement of a medieval building developed according to some experimental values obtained in an experimental campaign using wood specimens extracted from original beams and based on in situ measurements. This study is part of master thesis of Michael Andrade, an original research work.