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Time-varying mesh stiffness (TVMS) of gear plays vital role in analysing dynamic characteristic of gear transmission. So accurately evaluating the TVMS is important and essential. In this paper, a revised method to calculate the TVMS of helical gear is proposed. Based on slice method, the helical gear is sliced into pieces along the tooth width direction. The proposed method corrects the fillet foundation stiffness within multi-tooth in contact and considers the non-linearity and load-dependence of the Hertzian contact stiffness. The effect of the axial mesh force is considered. Finally, an equivalent helical gear model is established in ANSYS to study the mesh stiffness. The results show the proposed method has high effectiveness compared with FEM (finite element method).

The paper presents the numerical analysis of stress and strain occurring in the most wearable parts of hip and knee joints endoprostheses. The complexity of the processes taking place in both, natural and artificial joints, makes it necessary to conduct the analysis on the 3D model based on already existing mathematical models. Most of the mechanical failures in alloplasty are caused by material fatigue. To cut down the risk of it, we can either increase the fatigue resistance of the material or decrease the load strain. It is extremelly important to indicate the areas where damage or premature wear may occur. The Finite Elements Method makes it possible to calculate the stress and strain in particular elements of the tested models. All presented numerical calculations define quality conclusions concerning the influence of some parameters of endoprostheses on the values of stress and strain that are formed in polyethylene parts of endoprotheses of hip and knee joints. The obtained results help to reveal “weak points” in examined models and thus, counteract the subsequent effects resulting from premature wear of endoprosthesis elements. The numerical analysis was performed basing on the finite elements method using Autodesk Simulation Mechanical 2017 software and the ADINA 7.5.1.

The mathematical model and numerical simulation results of metals alloy solidification process based on the finite element method (FEM) are presented in this paper. After completion of the mould filling process the main solidified of molten metal takes place and its shrinkage. The phenomenon of casting shrinkage cannot be avoided. However, it is possible to minimize the occurrence of its negative effects on the casting quality. The phenomenon of shrinkage defects formation was included in the numerical calculations and they were tried to reduce them. It is important aspect of this work which makes possible the prediction of the location of the casting defect depending on shape of the riser. The results of computer calculations of the solidification process of the three-dimensional casting together with the conical or cylindrical riser are discussed in detail and presented.

Civil aviation is driven nowadays by exceptional growth in the number of passengers. It should double or even triple by 2050 and thus, all industrials also plan to double the number of device delivery by mid-century. Responsible for about 2% of carbon dioxide on the planet, they must now deal with the environmental issues facing the sector. At this moment in the world, several lines of research focus on increasing the efficiency of aircraft engines, development of new engines, efficient technologies, sustainable sources of alternative fuels and improved management air traffic on the ground and in flight [1]. The present work deals with a research focused on the engine test when passing in review in repair facilities. This operation which consist in making engine running while the cycles to test its performance in a test bench are studied to define a technological solution to reduce CO2 carbon footprint of the aircraft engine in this phase of the cycle of life. The idea is to produce electrical energy during these tests. To achieve this, we will highlight the case of a type bench facility for a specific airplane engines. As a result high-performance analysis tools are implemented to define the most suitable technological solution that ensures maximum efficiency, meets the functional and regulatory requirements taking into account the force of integration with the existing and cost optimization. In this paper we present the summary of the working definition of the research process for the final term set in the operating environment integration relevance that provides bench test and level of innovation that provides the methods selected.

The hot deformation behavior of Waspaloy alloy has been investigated by two-pass hot cogging process. The paper presents theoretical end experimental analysis of deformations and microstructural evolutions. The results of a thermo-mechanical simulation for the spatial hot cogging process on the shaped anvils with the application of the three–dimensional finite element method, are presented. The numerical calculation gave an assessment of the effective strain, mean stress and temperature distributions in the work-piece. Models for predicting the evolution of microstructure were developed for dynamic recrystallization and grain growth phenomena. The influence of shape of the anvils on the grain size after dynamic recrystallization was analyzed. The numerical analysis was performed using a commercial program "DEFORM 3D" with thermo-mechanical and microstructural evolution coupled. The results are compared with the experimental data, a good agreement between the predicted and experimental results was obtained.

In this paper thin-walled part deformation during finishing turning process caused by gripping force of hydraulic lathe chuck was investigated. Bearing ring was taken as an example of thin-walled part undergo finishing turning operation. Finite Element Method (FEM) was used to define the deformation of examined part. The aim of presented research was to compare the deformation of bearing ring caused by gripping force of hydraulic 3-jaw chuck and 6-jaw chuck for different values of total gripping force. The data obtained from conducted simulations allowed to evaluate the influence of gripping force on machining part deformation which is directly related with its geometrical accuracy.

The gantry cranes are currently one of the most popular devices to transporting loads. They can be used in many industries. This study focuses on the numerical analysis of only the portable gantry crane. The mathematical and numerical model of mechanical phenomena in the gantry crane beam was presented in this paper. This problem was solved by using of the Finite Element Method (FEM). The analysis was made to the cross-section of gantry crane beam which was the I-beam or box beam. The numerical simulations are limited to numerical analysis of strength of the gantry crane beam which was loaded by the motion of the load force along its length. As a result of the calculations, the stresses and displacements of the structure of gantry crane were obtained. The influence of beam shape change and changing the loading force position on generate the equivalent stress in the crane beam was evaluated. The research performed, which allows the estimated of the stress state, pointing out the critical areas and values, were made in order to increase the strength of the structure of the gantry crane.

The main topic of this paper is a static analysis of transmission tower beam structure fixed to the earth. It contains facts necessary for a need to create and apply tower beam structures. Beam elements were used to design a model and a static analysis was performed in finite element program Ansys Workbench. Three types of analyses were applied. The modal analysis was applied to verify the model compatibility. The static analysis was applied to find maximal deformations and the bending moment caused by overhead conductors and self-weight. Eigenvalue buckling was applied to state a loss of stability. Finally, stability and suitability of the whole construction was considered.

This paper presents results of numerical calculations of T-pipe joints (tee) forming process for a wide scope of industrial applications. FEM analyses were conducted for the chosen process technological parameters and tools designs. The kinematics of metal flow in the area of the formed flanges was analysed. Distributions of stresses, strains and damage criterion during forming were determined. Calculated values of forces and moments acting on tools and workpieces allow for designing of tools geometry for experimental verification of the proposed forming process.

This paper includes an analysis of the mechanical phenomena in the gantry crane beam, because the cranes are currently one of the most common devices for the transporting loads. Designing modern mechanical structures is a complex task that requires the use of appropriate tools. Such a modern tool is the numerical simulation, which uses different numerical methods. One of the best known methods is the finite element method, also used here. Simulations are limited to analysis of the strength of the gantry crane beam that was the loaded of the force load movement along its length. The numerical analysis was made to the gantry crane beam which cross-section was an I-beam and ends were fixed in different ways. As the result of numerical calculations, the stresses and displacements of the structure of gantry were obtained. The influence of the restraints type and changing the loading force position on generate the Huber-Misses stress in the gantry crane beam was estimated. The aim was to ensure that the maximum equivalent stress generated in the gantry crane beam was less than the strength of material, because then the construction is safe.

Numerical simulation is the main method to solve turbulence problems. As one of the three methods which are commonly used in large-eddy simulation model (LES) is the most effective and promising research method. The basic idea of large-eddy simulation is that the large scale turbulent motion is directly simulated and we use the sub-grid scale model to simulate small-scale turbulent motion. Continuing alternative load exists in aero-engine combustion chamber during operation. This coupling phenomenon is an important reason to the combustion chamber fatigue failure. In this paper, the large-eddy simulation methods are described and applied in researching aero-engine combustion chamber multi-physics field coupling analysis. By comparing with the experimental results we verify the feasibility of this method and there is great significance of actual project.