Modeling and validation of stray-field loss inside magnetic and non-magnetic components under harmonics-DC hybrid excitations based on updated TEAM Problem 21

Purpose This paper aims to propose and establish a set of new benchmark models to investigate and confidently validate the modeling and prediction of total stray-field loss inside magnetic and non-magnetic components under harmonics-direct current (HDC) hybrid excitations. As a new member-set (P21e) of the testing electromagnetic analysis methods Problem 21 Family, the focus is on efficient analysis methods and accurate material property modeling under complex excitations. Design/methodology/approach This P21e-based benchmarking covers the design of new benchmark models with magnetic flux compensation, the establishment of a new benchmark measurement system with HDC hybrid excitation, the formulation of the testing program (such as defined Cases I–V) and the measurement and prediction of material properties under HDC hybrid excitations, to test electromagnetic analysis methods and finite element (FE) computation models and investigate the electromagnetic behavior of typical magnetic and electromagnetic shields in electrical equipment. Findings The updated Problem 21 Family (V.2021) can now be used to investigate and validate the total power loss and the different shielding performance of magnetic and electromagnetic shields under various HDC hybrid excitations, including the different spatial distributions of the same excitation parameters. The new member-set (P21e) with magnetic flux compensation can experimentally determine the total power loss inside the load-component, which helps to validate the numerical modeling and simulation with confidence. The additional iron loss inside the laminated sheets caused by the magnetic flux normal to the laminations must be correctly modeled and predicted during the design and analysis. It is also observed that the magnetic properties (B27R090) measured in the rolling and transverse directions with different direct current (DC) biasing magnetic field are quite different from each other. Research limitations/implications The future benchmarking target is to study the effects of stronger HDC hybrid excitations on the internal loss behavior and the microstructure of magnetic load components. Originality/value This paper proposes a new extension of Problem 21 Family (1993–2021) with the upgraded excitation, involving multi-harmonics and DC bias. The alternating current (AC) and DC excitation can be applied at the two sides of the model’s load-component to avoid the adverse impact on the AC and DC power supply and investigate the effect of different AC and DC hybrid patterns on the total loss inside the load-component. The overall effectiveness of numerical modeling and simulation is highlighted and achieved via combining the efficient electromagnetic analysis methods and solvers, the reliable material property modeling and prediction under complex excitations and the precise FE computation model using partition processing. The outcome of this project will be beneficial to large-scale and high-performance numerical modeling.

Wind Load Analysis on A Multistoreyed Building Curved in Plan

: In this study a tall G+8 storied curved in plan (comprising an external and internal curved facade) has been analysed for wind acting in specified directions using STAAD pro v8i.For the curved profile, the wind load component has been calculated for each radial beam line. The combination of static load and wind load are taken into consideration. In the first case, the wind has been assumed to act towards the centre of the arc of the circle and in the second, away from the centre. The post processing reverberation in terms of bending moments, shear forces and support reactions has been studied in relation to the wind directions. Due to the effect of wind load on the structure, the storey-sage variation of the result with respect to different parameters are to be compared. The stiffness of the structure as a whole is expected to vary with the changed direction of the wind. The result would result in a parametric study of the effect of wind direction on curved profile. The orientation of the curved structure with respect to the direction of wind load has been studied.

Improvement of Physical Preparedness of Athletes in Classic Powerlifting at the Stage of Preparation for Higher Achievements Using Load Components Planning in Exercise Groups

Despite the active development of classical powerlifting in recent decades, the construction of training athletes in this division was based on the scientific achievements of researchers in equipment powerlifting, based on abrupt planning of sports volume and intensity of increasing load in the structural. Taking into account the impossibility of using significant indicators of volume and intensity in classical powerlifting, it is important to study ways to improve the construction of training powerlifters of different qualifications. The purpose of the study was to substantiate the effectiveness of the application of load component planning in groups of exercises in building the training of athletes in classical powerlifting at the stage of preparation for higher achievements. Material and methods. To achieve this goal we used theoretical analysis and generalization of data from scientific and methodological literature and the world information network Internet; documentary method; pedagogical observation; pedagogical experiment; methods of mathematical statistics. Based on the analysis of existing scientific knowledge and best practices, the need to find ways to improve training programs for athletes in classical powerlifting at the stage of preparation for higher achievements as one of the most important structural elements of athletes' athletic potential was substantiated. Results and discussion. As a result of the pedagogical experiment, there were significant differences in the performance of athletes of the control and experimental groups before and after the experiment in two of the four tests. Significant differences between the indicators of physical fitness of athletes in the control and experimental groups after the experiment were found in tests aimed at determining the level of development of strength capabilities. In two tests we found no significant differences between the indicators of the athletes of the experimental and control groups. Conclusion. The results of pedagogical experiment revealed reliable indicators of growth of physical fitness in three tests in athletes of experimental and control group. There were no reliable growth rates in both groups after the pedagogical experiment in the test "Running 30 m from a high start". The indicators of growth of physical fitness in the tests "Pull-up on the crossbar" and "Jumping from a place" in the athletes of the experimental group were higher than in the control group, which confirmed the higher efficiency of the author's powerlifters training program. Conclusion. Thus, planning load components in different groups of exercises in microcycles in accordance with their focus in the training of powerlifters in preparation for higher achievements allowed ensuring a sufficient level of adaptive shifts to increase athletes preparedness on the background of reducing the total annual load

Dynamic Modelling of Deep-Water Riser With Slug Flow Based on ALE-ANCF

The internal flow in gas-liquid mixing riser often displays a flow pattern known as slug flow, in which gas and liquid are alternately distributed. Dynamic effects due to slug flow is normally most obvious in areas along the riser with high curvature, which is caused by the centrifugal load component. The global riser response to this excitation can be predicted by nonlinear time domain analysis using the load model as described for slug flow conditions. In this study, the riser with internal slug flow is modeled under the framework of Arbitrary-Lagrange-Euler (ALE) description by using the Absolute Node Coordinate Formula (ANCF). The riser is discretized into ANCF cable element based on the Euler-Bernoulli beam assumption, while one-dimensional moving medium modeling method with time-varying density is used to model slug element. Compared with other FEA models of riser subjected to internal flow, the ALE-ANCF model allow easily modeling of complex mass flow and has the advantages of high speed and high precision in handling large deformation of riser, especially for the compliant riser configurations. Numerical simulations of two simplified models are carried out to validate the developed model, then the dynamic response such as displacement, tension force and bending moment of the riser conveying slug flow are analyzed.

A Multiple 1D Earth Approach (M1DEA) to account for lateral viscosity variations in solutions of the sea level equation: An application for glacial isostatic adjustment by Antarctic deglaciation

<p>The pseudo-spectral form of the sea level equation (SLE) requires the approximation of a radially-symmetric visco-elastic Earth. Thus, the resulting predictions of sea level change (SLC) and glacial isostatic adjustment (GIA) often ignore lateral variations in the Earth structure. Here, we assess the capabilities of a Multiple 1D Earth Approach (M1DEA) applied to large-scale ice load components with different Earth structures to account for these variations. In this approach the total SLC and GIA responses result from the superposition of individual responses from each load component, each computed globally assuming locally-appropriate 1D Earth structures. We apply the M1DEA to three separate regions (East Antarctica, West Antarctica, and outside Antarctica) to analyze uplift rates for a range of Earth structures and different ice loads at various distances. We find that the uplift response is mostly sensitive to the local Earth structure, which supports the usefulness of the M1DEA. However, stresses transmitted across rheological boundaries (e.g., producing peripheral bulges) present challenges for the M1DEA, but can be minimized under two conditions: (1) If the considered time period of ice loading for each component is consistent with the relaxation time of the local Earth structure. (2) If the load components can be subdivided according to the scale of the lateral variations in Earth structure. Overall, our results indicate that M1DEA could be a computationally much cheaper alternative to 3D finite element models, but further work is needed to quantify the relative accuracy of both methods for different resolutions, loads, and Earth structure variations.</p>