Calculation Scheme Research Articles

Determination of elastic characteristics for a package of monolayers thin-walled plates from composite fibrous materials

An analytical method for calculating the equivalent elastic characteristics of anisotropic multilayer plates made of composite fibrous materials is laid out. The main assumptions taken into consideration when calculating elastic moduli and Pousson's coefficients are that fibers are elastic materials with orthotropic mechanical characteristics that deform together when multilayer plates are loaded. Analytical methods for calculating effective modulus of elasticity most common in practical applications of applied mechanics are laid out in the list of cited publications. These include the rules of the mixture, the model proposed by Hill and Khashin, the model of Kilchinsky, the methods of Vanin and L.P. Khoroshun. Numerical methods for determining the elastic mechanical properties of reinforced unidirectional and layered composite materials are based on information technologies of finite-element modeling of representative volumes of composite materials and solving a number of boundary value problems for them. For the constructions of thin-walled plates with composite fibrous materials, traditional calculation schemes are used, for which the plane stress state is typical. The stress-strain relationship for a monolayer of plates loaded at an arbitrary angle is presented in the form of Hooke's law for aniotropic materials. Deformations of a package of monolayers with composite fibrous materials in a plane elastic-deformed state are determined, as for a monolayer, by four independent elastic constants. With the use of a universal calculation model based on the equations of applied mechanics, the results of the calculations of elastic moduli and Poisson's coefficients were obtained for a package of monolayers of thin-walled plates with composite fibrous materials made of carbon fiber and carbon fiber. Research results are presented in an analytical and graphic form. The influence of the construction structure of composite fibrous materials of thin-walled plates on its mechanical properties and their dependence on the angle of the force load vector is presented. The research results can be used to determine the rational mechanical properties of multilayer composite plates, taking into account their structural and technological purpose in various industries.

Using Total Monte Carlo with hybrid calculation methods for constructing the covariance matrix of a neutron spectrum: Applications in spectrum adjustment

A new calculation scheme has been developed to improve the quality of covariance matrices of a-priori neutron spectra. A high quality covariance matrix is essential for guiding the adjustment of the a-priori calculated neutron spectrum to experimental dosimetry measurements in a physically realistic way. This new calculation scheme incorporates state-of-the-art hybrid deterministic/Monte Carlo methods and does not rely on prior knowledge of correlations between the different energy groups. The ADVANTG code was used to generate weight-windows for the full MCNP reactor model of the High Flux Reactor (HFR) in Petten, the Netherlands. This then allowed Total Monte Carlo (TMC) calculations to be performed with very low statistical uncertainties. A detailed demonstration of applying these covariance matrices to spectrum adjustment is also provided by utilising an algorithm adopted from the STAY’SL program. We have used the example of the HELIOS irradiation experiment performed at the HFR to demonstrate the approach here, but the flexibility of the method means it may be applied universally to neutron spectra calculated anywhere.

DEPENDENCE OF TENSILE FORCE OF THE ELASTIC LIMIT STATE OF ROPES FROM THE BENDING PARAMETER ON THE DRUM

Based on the method previously developed by the authors for the analytical determination of the ultimate elastic state of the ropes, the dependence of the P(¯D) tensile force with the winding of the rope on the drum on the parameter ¯D=D_d/d_r (the ratio of the diameters of the drum and the rope) in the interval ¯D=10-120. Dependence P(¯D) was determined for two loading schemes of rope: stretching of the rope with winding on the drum with a freely suspended load and stretching of the rope with winding on the drum with the load in the guides. Based on the developed method, the dependence of P(¯D) was performed for 16 kantais of different designs. The tensile strength is presented in the relative form ¯P (¯D)=P(¯D)/P_t (P_t total breaking strength of the rope wires). The effort ¯P (¯D) significantly depends on the construction of the rope and the bending parameter ¯D. In the section 40≤¯D≤120 the force ¯P (¯D) increases monotonically and practically linearly, reaching the value corresponding to the calculation scheme of stretching a straight rope. For different structures with the parameter ¯D=40 change in force ∆¯D=0.723-0.578=0.145 with ¯D=120∙∆¯P=0.765-0.677=0.08. In the section 40≥¯D≥20 the dependence ¯P (¯D) is not linear, at ¯D=40∙∆¯P=0.663-0.418=0.245. The section 20≥¯D≥10 is characterized by a sharp change in force ¯P (¯D), with the bending parameter ¯D=10∙∆¯P=0.416. For most rope designs at ¯D<10 the forces ¯P (¯D) are close to zero values. When stretching with a freely suspended load, the forces ¯P (¯D) are 1.6–1.7 times lower than when stretching in guides. For twisting ropes (one-way winding), the ratio is 2.5–3.4 times. In the normative methods of calculations of lifting ropes, the characteristics P_t or P_a=0.83P_t are used, which do not take into account the peculiarities of the deformation and construction of the ropes. We believe that the given information is appropriate in solving the issue of building a methodology for calculating the static strength of lifting ropes based on the characteristics of their ultimate elastic state, which will ensure stable optimality of the use of ropes, will allow you to rationally choose the type of rope construction and its dimensions.

Validation of HiG-Flow Software for Simulating Two-Phase Flows with a 3D Geometric Volume of Fluid Algorithm

This study reports the development of a numerical method to simulate two-phase flows of Newtonian fluids that are incompressible, immiscible, and isothermal. The interface in the simulation is located and reconstructed using the geometric volume of fluid (VOF) method. The implementation of the piecewise-linear interface calculation (PLIC) scheme of the VOF method is performed to solve the three-dimensional (3D) interface transport during the dynamics of two-phase flows. In this method, the interface is approximated by a line segment in each interfacial cell. The balance of forces at the interface is accounted for using the continuum interfacial force (CSF) model. To solve the Navier–Stokes equations, meshless finite difference schemes from the HiG-Flow computational fluid dynamics software are employed. The 3D PLIC-VOF HiG-Flow algorithm is used to simulate several benchmark two-phase flows for the purpose of validating the numerical implementation. First, the performance of the PLIC implementation is evaluated by conducting two standard advection numerical tests: the 3D shearing flow test and the 3D deforming field test. Good agreement is obtained for the 3D interface shape using both the 3D PLIC-VOF HiG-Flow algorithm and those found in the scientific literature, specifically, the piecewise-constant flux surface calculation, the volume of fluid method implemented in OpenFOAM, and the high-order finite-element software FEEL. In addition, the absolute error of the volume tracking advection calculation obtained by our 3D PLIC-VOF HiG-Flow algorithm is found to be smaller than the one found in the scientific literature for both the 3D shearing and 3D deforming flow tests. The volume fraction conservation absolute errors obtained using our algorithm are 4.48×10−5 and 9.41×10−6 for both shearing and deforming flow tests, respectively, being two orders lower than the results presented in the scientific literature at the same level of mesh refinement. Lastly, the 3D bubble rising problem is simulated for different fluid densities (ρ1/ρ2=10 and ρ1/ρ2=1000) and viscosity ratios (μ1/μ2=10 and μ1/μ2=100). Again, good agreement is obtained for the 3D interface shape using both the newly implemented algorithm and OpenFOAM, DROPS, and NaSt3D software. The 3D PLIC-VOF HiG-Flow algorithm predicted a stable ellipsoidal droplet shape for ρ1/ρ2=10 and μ1/μ2=10, and a stable cap shape for ρ1/ρ2=1000 and μ1/μ2=100. The bubble’s rise velocity and evolution of the bubble’s center of mass are also computed with the 3D PLIC-VOF HiG-Flow algorithm and found to be in agreement with those software. The rise velocity of the droplet for both the ellipsoidal and cap flow regime’s is found, in the initial stages of the simulation, to gradually increase from its initial value of zero to a maximum magnitude; then, the steady-state velocity of the droplet decreases, being more accentuated for the cap regime.

METHOD OF CALCULATING THE UNSTATIONARY TEMPERATURE FIELD PARTS OF THE SPHERICAL FORM OF THE STRUCTURE FLIGHT APPARATUS OF UNMANNED AVIATION COMPLEXES

The design of unmanned aircraft vehicles during operation is exposed to significant temperature effects, which causes changes in the dielectric characteristics of radio technical elements and can lead to failures of on-board radio electronic equipment, as a result of which the task of determining the amount of temperature change in the compartments where the radio electronic equipment is located is performed. At the same time, some external elements of the aircraft vehicle can have complex structures with shapes close to spherical and different thicknesses in each cross-sectional structure.
 There is a need to develop a method for calculating the non-stationary temperature field with the purpose of finding out the real conditions in which all the elements of the aircraft structure work, which would help to determine how the temperature of the structure changes during any flight. At the same time, it is necessary to take into account the three dimensions of temperature gradients on spherical parts of structures of various shapes, namely nose part, rounded wing and others. In them, as a rule, each cross-section of the wall has its own thickness and, according to each cross-section, the temperature distribution along the thickness of the wall will correspond, that is, it is necessary to ensure the redistribution of temperature along the structural element, the calculation of which month. In addition, it is necessary to note that the wall of the aircraft can be multi-layered and the properties of its material can change along with the change in temperature. Considering the fact that it is impossible to take into account all the listed features by analytical methods, when choosing a calculation method, it will be advisable to stop at numerical methods.
 One of the most well-known numerical methods is the finite difference method with an implicit calculation scheme, which has an indisputable advantage for modeling - absolute stability with sufficient changes in time and coordinate steps. We will use the level of thermal conductivity in spherical coordinates in order to increase the accuracy of the calculation, for which solution, after finding out the boundary conditions, we will perform a one-dimensional calculation of the temperature by thickness in each mesh section of the structure, and also perform a calculation of the two-dimensional "heat flow" along the solid between the points, that are located on the same thickness, but have a temperature difference. Thus, when calculating the temperature field, the sphericity and multi-lay redness of the structural elements is taken into account, and the property of the material of the aircraft structure changes depending on the temperature.

MAGIC-GPS global variance reduction method for large-scale shielding calculation

We propose a Method of Automatic Generation Importance by Calculation with Growth Population Scheme (MAGIC-GPS) for efficient and accurate shielding calculation. The new method adopts a Growth Population Scheme (GPS) in the reciprocal iteration process of flux and importance for the Monte Carlo fixed-source calculation. Mathematical derivation is performed to prove that the GPS scheme is conducive to a rapid flux distribution convergence and can improve the Figure of Merit (FOM) of the Monte Carlo deep-penetration simulation. The effectivity of the MAGIC-GPS method is tested by a single concrete rod model, the H.B. Robinson-2 reactor benchmark (HBR2) and the China Fusion Engineering Test Reactor (CFETR). The results show that the MAGIC-GPS method can accelerate the Monte Carlo deep-penetration simulation, and the faster the population of particles increases, the better the acceleration. The MAGIC-GPS method is helpful for large-scale shielding calculation.

MBD + C: How to Incorporate Metallic Character into Atom-Based Dispersion Energy Schemes.

The dispersion component of the van der Waals interaction in low-dimensional metals is known to exhibit anomalous "Type-C non-additivity" [Int. J. Quantum Chem. 2014, 114, 1157]. This causes dispersion energy behavior at asymptotically large separations that is missed by popular atom-based schemes for dispersion energy calculations. For example, the dispersion interaction energy between parallel metallic nanotubes at separation D falls off asymptotically as approximately D-2, whereas current atom-based schemes predict D-5 asymptotically. To date, it has not been clear whether current atom-based theories also give the dispersion interaction inaccurately at smaller separations for low-dimensional metals. Here, we introduce a new theory that we term "MBD + C". It permits inclusion of Type C effects efficiently within atom-based dispersion energy schemes such as many body dispersion (MBD) and universal MBD (uMBD). This allows us to investigate asymptotic, intermediate, and near-contact regimes with equal accuracy. (The large contact energy of intimate metallic bonding is not primarily governed by dispersion energy and is described well by the semi-local density functional theory.) Here, we apply a simplified version, "nn-MBD + C", of our new theory to calculate the dispersion interaction for three low-dimensional metallic systems: parallel metallic chains of gold atoms, parallel Li-doped graphene sheets, and parallel (4,4) armchair carbon nanotubes. In addition to giving the correct asymptotic behavior, the new theory seamlessly gives the dispersion energy down to near-contact geometry, where it is similar to MBD but can give up to 15% more dispersion energy than current MBD schemes, in the systems studied so far. This percentage increases with separation until nn-MBD + C dominates MBD at asymptotic separations.

Calculation scheme for thermal neutron scattering cross-sections of hydrogenous molecules in liquid and solid phases by molecular dynamics

For systematic analysis of the neutronics properties of various hydrogenous materials that can be candidates for cold moderators, a calculation scheme for thermal neutron scattering cross-sections (TNSCs) of hydrogenous molecules in liquid and solid phases is developed in combination with molecular dynamics simulations. For a feasibility study of the present scheme, TNSCs of liquid and solid mesitylene are calculated, and the neutron spectrum in solid mesitylene is analyzed by using generated thermal scattering law data. Furthermore, by comparing calculated total cross-sections of other 14 hydrogenous molecules with experimental data, a wide usefulness of the present scheme is confirmed.

First-principles calculations to investigate structural, electronic, optical and elastic properties of α-Ca3N2

The optoelectronic industry, which has become a cornerstone, requires a semiconductor compound to function as a sustainable and green energy source. In this connection, the present study provides a systematic approach to examine the electronic and optical properties of α-Ca3N2 using the linear combination of atomic orbitals method. The xc-functional BECKE-PBE gives the best results for electronic properties by describing the band gap correctly. The dispersion curve shows that α-Ca3N2 is a semiconductor with an indirect band gap of 1.33 eV along the H-Γ direction. Effective masses of electrons and holes are calculated at the peak of the lowest conduction band and highest valence band, along the Γ- direction. Calculation for optical properties has been performed using coupled-perturbed Hartree-Fock scheme for static values and phonon spectrum calculations are performed for dynamic dielectric functions. Further, frequency dependent electron loss function and reflectivity are determined from the dielectric functions. The elastic constants are estimated and elastic moduli are determined. Bulk modulus of 80.6 GPa and Poisson’s ratio of 0.275 reveals that α-Ca3N2 is a hard and ductile material. The characteristic properties of α-Ca3N2 make it a suitable candidate for optoelectronic applications.

Pelatihan Dan Pendampingan Tata Cara Penghitungan Waris Bagi Santri Pondok Pesantren Al Urwatul Wutsqo Jombang

Pondok Pesantren Al Urwatul Wutsqo Jombang is an Islamic educational institution that has an important role in shaping the character and understanding of religion among the citizens. One of the crucial aspects of Islamic religion is the law of inheritance, which regulates the division of property after a person dies. A proper understanding of the system of inheritance counting is crucial to ensuring justice and harmony in society. This study is a community dedication aimed at improving the understanding of the methods of counting inheritance among the centers of Pondok Pesantren Al Urwatul Wutsqo Jombang. The approach involved theoretical training and practical support, as well as close collaboration with the hostel manager. This training covers a basic understanding of faraidh, the principles of inheritance counting in Islam, and their practical application. The results of the study showed a significant improvement in the central understanding of the methodology of inheritance counting. Santri not only understands the basic principles of inheritance law but is also able to apply them in real-life situations. Besides, the program also empowers centers to be agents of change in their communities. The program has planned advanced activities to maintain a sustainable understanding of the hereditary calculation scheme among the centurions. Although there are some obstacles during implementation, such as a tight timetable, steps will be taken to address these challenges in the future. The dedication of this community was successful in improving the understanding of the methods of counting inheritance among the centers of the Pondok Pesantren Al Urwatul Wutsqo Jombang. It shows the importance of inclusive and interactive religious education in shaping individual character and instilling the values of justice in society.

Determination of the installation height of the meat grinder grate with a vertical screw arrangement above the upper edge of the container

Processing of agricultural products plays an important role in providing food to the population of our country. Therefore, increasing productivity in the processing of raw materials is an urgent task, including in the production of meat products. Thus, in the production of minced meat, the replaceable productivity may decrease due to the loss of time for sanitary and hygienic treatment of premises and equipment, which is provided for by regulatory documents. During the production of minced meat, meat juice can be sprayed on the surrounding objects and walls of the room, which aggravates their sanitary and hygienic treatment. It is possible to eliminate the spraying of meat juice by improving the equipment used for the production of minced meat. To reduce the splashing of meat juice in the production of minced meat, the article proposes a meat grinder with a vertical screw arrangement, for which a patent for a utility model has been obtained. The vertical output of minced meat allows you to limit the spraying within the container for the finished product. At the same time, the distance between the grate of the meat grinder and the container for the finished product should be maximum, but in such a way as to almost completely exclude the ingress of splashes of meat juice outside the container. To determine this distance (the height of the meat grinder installation above the container), the corresponding theoretical prerequisites are proposed on the basis of the developed calculation scheme and the well-known mathematical apparatus. Formulas have been obtained for determining the maximum distance from the clamping nut of the meat grinder to the upper edge of the container, excluding splashes of meat juice outside the container. The maximum distance depends on the geometric dimensions of the grate of the meat grinder and the container for the finished product. A dependence is also derived to determine the minimum diameter of the minced meat container, which excludes the spraying of raw materials beyond its limits. In general, the proposed design of the meat grinder and the justification of its parameters will significantly reduce the spraying of meat juice on surrounding objects. This will reduce the time for sanitary and hygienic processing and, thereby, increase the shift productivity in the production of minced meat.

Wyznaczanie siły tarcia pomiędzy cięgłem a prowadnicą cięgła w żerdziowych pompach wgłębnych oraz analiza odkształcenia naprężeniowego zespołu zaworowego

The article is devoted to the determination of the friction force between the draw rod and the guide and to the analytical study of the stress deformation state of the valve assembly of the rod well pump. In sucker rod well pumps, a hollow cylindrical guide is used to ensure the same axis of the plunger as the cylinder during operation. The guide is attached to the upper end of the pump cylinder. The draw rod connecting the sucker rod and the plunger of the pump moves up and down in the internal cylindrical cavity of the guide in the corresponding movements of the balancer head. There must be a certain clearance between the draw rod and the guide to ensure free movement of the draw rod. Based on the calculation scheme for determining the friction force between the draw rod and the guide is given, and the necessary parameters are determined. According to the values obtained from the calculation, the graphs were built based on the dependences of the friction force between the draw rod and the guide on the angle φ, and on the path of the plunger when φ = 30. At the same time, according to the calculation scheme of the "ball-saddle" pair, the force acting on the ball, the stresses generated on the contact surfaces of the ball and the saddle, and other parameters were found. The friction and wear between the draw rod and the guide is also typical of the friction and wear between the polished rod and the wellhead forming structure. Because, in the latter case, as a result of the suspension point of the balancer head not having the same axis as the wellhead, the polished rod cannot move with the straight axis in wellhead valve.

Oerlemans Minimal Model as a Possible Instrument for Describing Mountain Glaciation in Earth System Models

The main approaches to mountain glacier simulation were reviewed, and Oerlemans minimal model was chosen as a parameterization core of mountain glaciation in the Earth System models. The proposed model is based on a one-dimensional equation of glacier mass balance. The mass balance components are calculated with the use of a specially developed model of orographic precipitation, an algorithm for correction of incoming solar radiation onto an inclined ice surface, and schemes of calculation of turbulent heat-moisture exchange based on the Monin–Obukhov theory. The model was implemented for the Djankuat glacier (the Central Caucasus), for which a long measurement series is available. The model gives a good reproduction of the dynamics of glacier length over the period 1985–2020 based on measured mass balance values: –13 m/year, which is in practically perfect agreement with the field data. This means that the Oerlemans model can be used in Earth system models. The results of simulation based on the calculated mass balance showed a significant positive trend in ablation at a slight change in accumulation, which is also in agreement with the reality. However, in this case, the values of the annual thawing depth and the glacier contraction are twice as large and those observed in reality. The further development of the model (the inclusion of a snow cover block, the incorporation of debris mantle and mountain–valley circulation) will eliminate these shortcomings.

Calculation of the Constructive Nonlinearity of Ribbed Reinforced Concrete Slabs of Self-Stressed Covering Panels

Abstract Precast reinforced concrete constructions meet the requirements of industrialization, high manufacturability, and cost-effectiveness at a reasonably high level. The ribs in constructions perform load-bearing functions, and the slab part performs enclosing functions. Often before the installation of such structures at a construction site, they are mounted from assembly elements. The overall dimensions of the elements are limited by transportation requirements. During such an aggregated mounting, the assembly units work according to a calculation scheme that differs from an operational scheme. The structural nonlinearity of ribbed reinforced concrete slabs during transportation, mounting, and installation, and the operation of a combined spatial covering panel were investigated in this paper. The effects were identified, and a rational design of nodes connecting the individual prefabricated units into a spatial structure was developed. With the help of these nodes, it is possible to create unloading support moments, which will reduce the internal forces in the design cross-sections. The effects of changes in the width of the reinforced concrete slab shelves on the internal forces of the load-bearing ribs of a wall and a roof panel were investigated.

Prediction of IOL decentration, tilt and axial position using anterior segment OCT data

BackgroundIntraocular lenses (IOLs) require proper positioning in the eye to provide good imaging performance. This is especially important for premium IOLs. The purpose of this study was to develop prediction models for estimating IOL decentration, tilt and the axial IOL equator position (IOLEQ) based on preoperative biometric and tomographic measures.MethodsBased on a dataset (N = 250) containing preoperative IOLMaster 700 and pre-/postoperative Casia2 measurements from a cataractous population, we implemented shallow feedforward neural networks and multilinear regression models to predict the IOL decentration, tilt and IOLEQ from the preoperative biometric and tomography measures. After identifying the relevant predictors using a stepwise linear regression approach and training of the models (150 training and 50 validation data points), the performance was evaluated using an N = 50 subset of test data.ResultsIn general, all models performed well. Prediction of IOL decentration shows the lowest performance, whereas prediction of IOL tilt and especially IOLEQ showed superior performance. According to the 95% confidence intervals, decentration/tilt/IOLEQ could be predicted within 0.3 mm/1.5°/0.3 mm. The neural network performed slightly better compared to the regression, but without significance for decentration and tilt.ConclusionNeural network or linear regression-based prediction models for IOL decentration, tilt and axial lens position could be used for modern IOL power calculation schemes dealing with ‘real’ IOL positions and for indications for premium lenses, for which misplacement is known to induce photic effects and image distortion.

Experimental study on the energy loss from flow and electrical of vanadium battery with constant pump frequency

When the vanadium battery was running, pump frequency and current density were two frequently adjusted parameters. When the pump frequency was constant, the main flow-electrical parameter variation needs to be further studied. To this end, a 10 kW vanadium battery was built. When the current density was relatively high during the charge-discharge, the flow-electrical parameters of the cathode and anode including the temperature, flow resistance, turning voltage difference, capacity loss, energy loss and energy efficiency were studied. Besides, the compositions of capacity and energy were introduced, and the loss calculation scheme was proposed. Firstly, in flow analysis, the flow resistance was defined, which represents the flow state of the electrolyte. It was found that the flow resistance was nearly linear with the temperature. Secondly, in electric analysis, the turning voltage difference increased with the current density increasing. For the same current density, the total energy loss of charge was less than the discharge, and the energy loss of bypass was less than the internal resistance. With the current density increasing, the energy efficiency decreased. The research can be provided insight into the optimizing operation for the vanadium battery.

A cross-section correction model for history effect treatment in pin-by-pin code NECP-Bamboo2.0

The consideration of the history effect is one of the foundations for ensuring the precision of the two-step calculation scheme. Since the actual condition could not be predicted in advance, the standard approach of the lattice calculation adopts the branch-based model in which the variations of nuclide number densities with burnup are only considered in averaged operating conditions. Consequently, the nuclide number densities associated with actual operating conditions are not considered properly in the 3D whole-core calculation, and the problem of the history effect arises then. The microscopic depletion method and serval correction methods based on different lattice calculation structures were developed to solve this problem and have been employed in pin-by-pin two-step calculation codes. This paper introduces a new spectral history correction method with the implementation of a new bidirectional branch model, a pin-cell burnup correction model, and a multiscale cross-section correction model. The work was carried out based on the pin-by-pin fuel management calculation code system NECP-Bamboo2.0 developed by Xi'an Jiaotong University. Encouraging conclusions have been obtained from the numerical results. For the heterogeneous history effect caused by CR movement, the bias of keff given by the classical corrections will exceed ± 1000pcm. In contrast, the improved method can reduce it to be smaller than ± 250pcm. For the histories triggered by the changes of other state parameters, including boron concentration, fuel, and/or moderator temperature(s), the new cross-section correction method is comparable in accuracy to the traditional microscopic cross-section correction method, both better than the microscopic depletion correction method.

High-throughput study of the anomalous Hall effect

Despite its long history, the anomalous Hall continues to attract attention due to its complex origins, its connection to topology, and its use as a probe of magnetic order. In this work we investigate the anomalous Hall effect in 2871 ferromagnetic materials using an automatic high-throughput calculation scheme. We analyze general properties of the effect, such as its reliance on spin-orbit coupling strength and magnetization. In materials with the largest anomalous Hall effect, we find that symmetry-protected band degeneracies in the non-relativistic electronic structure, such as mirror symmetry-protected nodal lines, are typically responsible for the large effect. Furthermore, we examine the dependence of the anomalous Hall effect on magnetization direction and demonstrate deviations from the commonly assumed expression jAHE ~ M × E.

Holistic Evaluation of Demand Response Events in Real Pilot Sites: From Baseline Calculation to Evaluation of Key Performance Indicators

Explicit demand response plays a significant role in the future energy grid transition, as it involves end consumers in smart grid activities and, at the same time, exploits the potential of flexibility, giving the opportunity to grid operators to accommodate a total amount of energy without the need to reinforce the grid infrastructure. For evaluating the successfulness of a demand response program, thus, evaluating its advantages, it is fundamental to have an accurate baseline curve consumption along with meaningful key performance indicators. In this work, we propose a novel way of calculating the baseline consumption using artificial intelligence techniques. In particular, regression models have been applied to a database of historical data. In order to present a complete evaluation of demand response programs, we present five key performance indicators (KPIs). The KPIs have been selected so as to depict the successfulness of the explicit demand response program. We suggest a novel way of evaluating two of the five KPI using a quantitative approach. We also apply the proposed methodology for baseline calculation and KPIs evaluation in a practical example: two pilot sites have been used and real-life scenarios of demand response events have been applied for this scope to actual nonindustrial consumers and especially residential consumers. The baseline has been calculated for these pilot sites and the KPIs have been evaluated for them. The presented results complete the picture of evaluating a real-life demand response program and show the effectiveness of the selected approach. The proposed schemes for baseline calculation and KPI evaluation can be used by the scientific community for evaluating future demand response programs, especially in the residential sector.

ProCrackPlast: a finite element tool to simulate 3D fatigue crack growth under large plastic deformations

Many structural components and devices in combustion and automotive engineering undergo highly intensive cyclic thermal and mechanical loading during their operation, which leads to low cycle (LCF) or thermomechanical (TMF) fatigue crack growth. This behavior is often characterized by large scale plastic deformations and creep around the crack, so that concepts of linear-elastic fracture mechanics fail. The finite element software ProCrackPlast has been developed at TU Bergakademie Freiberg for the automated simulation of fatigue crack growth in arbitrarily loaded three-dimensional components with large scale plastic deformations, in particular under cyclic thermomechanical loading. ProCrackPlast consists of a bundle of Python routines, which manage finite element pre-processing, crack analysis, and post-processing in combination with the commercial software Abaqus . ProCrackPlast is based on a crack growth procedure which adaptively updates the crack size in finite increments. Crack growth is controlled by the cyclic crack tip opening displacement varDelta CTOD, which is considered as the appropriate fracture-mechanical parameter in case of large scale yielding. The three-dimensional varDelta CTOD concept and its effective numerical calculation by means of special crack-tip elements are introduced at first. Next, the program structure, the underlying numerical algorithms and calculation schemes of ProCrackPlast are outlined in detail, which capture the plastic deformation history along with the moving crack. In all simulations, a viscoplastic cyclic material law is used within a large strain setting. The numerical performance of this software is studied for a single edge notch tension (SENT) specimen under isothermal cyclic loading and compared to common finite element techniques for fatigue crack simulation. The capability of this software is featured in two application examples showing crack growth under mixed-mode LCF and TMF in a typical austenite cast steel, Ni-Resist. In combination with a crack growth law identified in terms of varDelta CTOD for a specific material, the tool ProCrackPlast is able to predict the crack evolution in a 3D component for a given thermomechanical loading scenario.