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Introduction. Solving a wide range of problems to maintain the strength of train undercarriage under the impact of ballast particles, such as ice chunks, during the cold season is considered a topical issue for high-speed railways. Solid objects are lifted off the track surface as a result of aerodynamic interaction with the turbulent airflow of a high-speed train. This causes mechanical damage to the bogie and its components, which could be significant and endanger road safety. The aim of this study is to assess the probability of significant damage to the traction gearbox housing from foreign objects on the way and to develop a method of protection.Materials and methods. Housing failure potential is calculated using numerical simulation in MSC.Nastran_SOL700 environment, allowing analysis of short duration dynamic events with severe geometry and material non-linearity. The method of assessment of the structural strength of a traction gearbox housing under the dynamic action of a foreign object is described.Results. The calculation methodology is tested on a simplified traction gearbox housing model. The methodology is then applied to models that are close to the real traction gearbox housing. The General model and the Cowper — Simonds model, which incorporates the strain rate dependence of the dynamic deformation of the material, are considered for specifying the material properties. The effect of foreign objects of different masses and relative speed on the probability of damage to the traction gearbox walls at different thicknesses is assessed.Discussion and conclusion. Calculations confirm the probability of destruction of housings of traction gearboxes of high-speed and high-speed electric trains under the dynamic impact on the body of third-party objects. Structural solutions for protecting housings of traction gearboxes of high-speed trains from the effects of foreign objects are analysed and the most rational option is chosen. This article was written based on the authors' paper presented at the XXII Russian MSC Software Conference (HxGN Live Design & Engineering Russia 2021), November 16-19, 2021.

Objective. The objective of this work is to solve an unrelated dynamic problem of thermoelectroelasticity for a long hollow piezoceramic cylinder under the action of an electric load on its surfaces in the form of a potential difference.Methods. The mathematical formulation of the considered problem of thermoelectroelasticity includes a system of non-selfadjoint differential equations. At the first stage, the authors consider the associated inverse piezoelectric effect problem without taking into account the influence of the temperature field, and at the next stage, study the hyperbolic heat conduction problem (Lord–Shulman theory) for a given (defined) electroelastic field.Result. A new closed solution to the dynamic inverse piezoelectric effect problem for a long piezoceramic thermoelastic cylinder is constructed. The case of the action of a dynamic electric load in the form of a potential difference on its front surfaces is considered. The ambient temperature and the law of convection heat transfer (3-kind boundary condition) are set. The calculated relations obtained using the generalized method of finite integral transformations allow determining the stress-strain state and thermoelectric fields induced in a piezoceramic element under an arbitrary electrical external influence.Conclusion. The constructed solution allows determining the stress-strain state and electric field in a piezoceramic cylinder, as well as analyzing the effect of the induced temperature field on the electroelastic state of the system under consideration using the hyperbolic Lord–Shulman theory of thermal conductivity. Analysis of the numerical results allows concluding that there are insignificant energy losses associated with heating the electroelastic system. The developed calculation algorithm is used in the design of non-resonant and resonant piezoelectric measuring devices.

The article presents the physico-mathematical modeling of the dynamic effect of the melt on a nanoscale particle during the formation of coatings by induction centrifugal surfacing. The forces acting on the particle in the liquid melt during the isothermal holding under induction prismatic welding are determined. A dependence is obtained that determines the rate of displacement of nano-sized particles from the initial position in the liquid melt during surfacing of the coating. A method for the formation of coatings with nano-sized additives is developed by induction centrifugal surfacing, including preliminary preparation of the bronze charge. It is shown that the introduced nanoscale additive in an amount of 4 wt.% to the powdered charge of tin bronze, according to the proposed method, leads to its phase-structural transformations, which allows achieving higher anti-frictional properties of bronze, since a uniform distribution of the solid structural component throughout the whole coating is ensured. The detected factors lead to an increase in the tribotechnical properties of coatings — a reduction in the coefficient of friction with simultaneous increase in wear resistance and micro-hardening of coatings.

Copyright of Advanced Engineering Science / Gongcheng Kexue Yu Jishu is the property of Advanced Engineering Science Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to study the change law of excess pore water pressure of earth-rock dam under dynamic action and its influence on the dam slope stability, a certain dam is used as the research object. The see/w, slope/w and quake/w module in the geo-slope software are used for analyzing the development law of excess pore water pressure of the dam under dynamic action, the displacement changes of typical nodes of the dam body, and the dynamic stability of the dam slope. The calculation results show that under the effect of the fortification intensity of VII, the dam body's infiltration line has been elevated, and the elevation is about 0.2m. The development rate of excess pore water pressure of the liquefiable soil layer directly below the dam is relatively slow, and the development level of excess pore water pressure of the liquefiable soil layer on the water side is the highest. The top displacement of the dam is the largest, followed by the middle of the dam, and finally the foot of the dam. The time point of the maximum displacement is lagging behind the time point of the maximum input acceleration. In the process of dynamic action, the upstream dam slope has a safety factor of less than 0 and may be unstable, but the downstream dam slope has remained stable. This study can provide a reliable reference for the stability study of earth rock dam slope under complex geological environment, and effectively prevent the occurrence of geological disasters. [ABSTRACT FROM AUTHOR]

The results of a numerical study in a three-dimensional formulation of the processes of elastoplastic deformation of a cubic single crystal based on the Ni3 Al intermetallic (VZHM8) under impact loading are presented. Impact loading is carried out in the [001] direction. The development of deformation processes is studied in the [100] and [010] or [011] and [011] directions. In the former case, the crystallographic directions of the single crystal coincide with the axes of the computational coordinate system and the elastic constants in these directions are the same. In the latter case, only one axis coincides with the [100] crystallographic direction, the other two are rotated by an angle of 45°. It is shown that a change in the elastic constants of a single crystal in new directions results in a change in the volume compressibility in all three directions. This is a consequence of the generalized Hooke's law. In the mathematical model used in this work to describe elastoplastic deformation, it is assumed that the volume compressibility of the single crystal is constant in the region of elastic and plastic deformations. It is shown for the first time that with the above rotation of the coordinate axes in a cubic single crystal, a change in elastoplastic deformations in the direction of the axis of impact loading is observed. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A methodology is developed for physical (laboratory) simulation of the long-term dynamic action of plasma beam high-energy ions on a space debris object with the aim of removing it to a lower orbit followed by its burning in the Earth's atmosphere. The methodology is based on the use of a criterion for the equivalence of two plasma beam exposure regimes (in the Earth’ ionosphere and in laboratory conditions) and an accelerated test procedure in what concerns space debris object material sputtering and space debris object erosion by a plasma beam in the Earth's ionosphere. The space debris coating material (blanket thermal insulation) sputtering yield and normal and tangential momentum transfer coefficients are determined experimentally as a function of the ion energy and the ion beam incidence angle. [ABSTRACT FROM AUTHOR]

The paper deals with numerical modelling of dynamic load acting on a footbridge. Two cases of loads caused by passing people have been considered: the load caused by crowd of people and by random stream of people. Moreover, two cases of vandalistic actions have been taken into account. Vandalistic action is such purposeful human action which leads to damage or destruction of an object. Numerical analyses have been carried out for the real footbridge for pedestrians and bicycles traffic over Vistula River in Cracow. Modal analysis was the first step of calculations and on this basis various variants of dynamic actions have been assumed. All computations have been performed with use of FEM system - ALGOR.

In many application scenarios, for example in design or media production processes, several authors have to work cooperatively on the same project and consequently on the same data. In this context, a frequently used data format is XML. To enable cooperative authoring of shared XML graph structures, several requirements have to be fulfilled, e.g., early visibility of updates, multi-directional information flow, and processing data in parallel. Most transaction models proposed in the literature are hardly applicable in this context. In this paper, we propose a novel transaction model based on multi-level transactions and dynamic actions that meets these requirements. We describe the transaction model as well as its formal properties and discuss issues such as synchronization and logging. [ABSTRACT FROM AUTHOR]

Abstract: There has been considerable interest in identifying the neural correlates of action naming, but the bulk of previous work on this topic has utilized static stimuli. Recent research comparing the visual processing of dynamic versus static actions suggests that these two types of stimuli engage largely overlapping neural systems, raising the possibility that the higher-order processing requirements for naming dynamic and static actions might not be very different. To explore this issue in greater depth, we developed the Dynamic Action Naming Test (DANT), which consists of 158 video clips 3–5s in length, for each of which the participant is asked to produce the most appropriate verb. We administered the DANT to 78 brain-damaged patients drawn from our Patient Registry, and to a demographically matched group of 50 normal participants. Out of the 16 patients who performed defectively on the DANT, nearly all (15/16) had damage in the left hemisphere. Lesion analysis indicated that the frontal operculum was the most frequent area of damage in the 15 patients; also, damage to the posterolateral temporal-occipital sector (in and near MT) was specifically related to defective dynamic action naming. Most of the brain-damaged participants (n =71) also received our Static Action Naming Test (SANT), and we found that performances on verb items that were common across the DANT and SANT were highly correlated (R =.91). Moreover, patients who failed the DANT almost invariably also failed the SANT. These findings lend further support to the hypothesis that there is considerable commonality in the neural systems underlying the use of verbs to orally name dynamic and static actions, a conclusion that is in turn compatible with the concept of “representational momentum”. Our results also contribute more generally to the rapidly growing field of research on embodied cognition. [Copyright &y& Elsevier]