Some constraints on the Yukawa parameters in the neutrino modification of the Standard Model (nuMSM) and CP-violation

The equations connecting elements of the Yukawa matrix to elements of the active neutrino mass matrix in the \nu MSM theory (an extension of the Standard Model by a singlet of three right-handed neutrinos) was analyzed, and explicit relations for the ratio of the Yukawa matrix elements through elements of the active neutrino mass matrix were obtained. This relation can be used for getting more accurate constraints on the model parameters. Particularly, with the help of the obtained results we investigated CP-violating phase in the \nu MSM theory. We demonstrate that even in the case when elements of the active neutrino mass matrix are real the baryon asymmetry can be generated also.Comment: 14 pages, 2 figures, many clarifications and references adde

8-MW wind turbine tower computational shell buckling benchmark. Part 1:an international ‘round-robin’ exercise

An assessment of the elastic-plastic buckling limit state for multi-strake wind turbine support towers poses a particular challenge for the modern finite element analyst, who must competently navigate numerous modelling choices related to the tug-of-war between meshing and computational cost, the use of solvers that are robust to highly nonlinear behaviour, the potential for multiple near-simultaneously critical failure locations, the complex issue of imperfection sensitivity and finally the interpretation of the data into a safe and economic design.This paper reports on an international ‘round-robin’ exercise conducted in 2022 aiming to take stock of the computational shell buckling expertise around the world which attracted 29 submissions. Participants were asked to perform analyses of increasing complexity on a standardised benchmark of an 8-MW multi-strake steel wind turbine support tower segment, from a linear elastic stress analysis to a linear bifurcation analysis to a geometrically and materially nonlinear buckling analysis with imperfections. The results are a showcase of the significant shell buckling expertise now available in both industry and academia.This paper is the first of a pair. The second paper presents a detailed reference solution to the benchmark, including an illustration of the Eurocode-compliant calibration of two important imperfection forms

The destructive effect of temperature on the operation of steel covers of large spans

Przedmiotem rozważań zaprezentowanych w pracy są przemieszczenia i naprężenia w elementach stalowych dźwigarów kratowych, spowodowane zmianami temperatury zewnętrznej i nierównomiernym rozkładem temperatur wewnątrz hali. Wielodniowe pomiary przemieszczeń stalowych, kratowych dźwigarów dachowych dużej rozpiętości połączone z pomiarami temperatury w przestrzeni hali i w różnych punktach dźwigarów wykazały znaczący wpływ nierównomiernego rozkładu temperatur na przemieszczenia. Zmierzone wartości przemieszczeń zostały porównane z przemieszczeniami otrzymanymi drogą symulacji numerycznych, w których danymi wejściowymi były pomierzone temperatury. Poza przemieszczeniami w pracy przeanalizowano także wzrost naprężeń w wybranych elementach dźwigara kratowego, spowodowany nierównomiernym rozkładem temperatur. Oceniono destrukcyjny wpływ temperatury na stan wytężenia analizowanych stalowych dźwigarów kratowych.The subject of considerations presented in the work are displacements and stresses in steel elements of truss girders, caused by changes in the external temperature and uneven distribution of temperatures inside the hall. Multi-day measurements of displacement of steel, large-span truss roof girders combined with temperature measurements in the hall space and at various points of the girders showed a significant influence of uneven temperature distribution on the displacements. The measured displacement values were compared with the displacements obtained by numerical simulations, in which the input data were measured temperatures. In addition to displacements, the increase of stress in selected elements of the truss girder, caused by uneven temperature distribution, was also analyzed in the paper. The destructive effect of temperature on the strain and stress state of the analyzed steel truss girders was assessed

Dynamic Reductions for the Nonlinear Soil-Foundation-Structure System Interactions

The article presents new dynamic superelements for DOF (degrees of freedom) reduction. Proposed spectral superelements (SES) are based on the method of normal coordinates. The developed superelements with basis nodes (SEB) for the inhomogeneous systems are also shown. Proposed superelements ensure to obtain the diagonal matrix of masses which allow to use the efficiency of explicit method. The results of nonlinear analysis using proposed reduction method for the group of high-rise building are presented. The calculations were performed by explicit method with the help of Automated System of Scientific Research (ASSR) “VESNA-DYN”

Stress distribution in column-plate foundations of Monument of Christ The King erected in Świebodzin

The paper presents results of numerical simulations of the stress distribution and deformations within of foundations of huge monument of Christ The King erected in Świebodzin (Poland) in 2010. It is 3 meters taller than the better known statue of Christ the Redeemer in Rio de Janeiro, standing at 30.1 meters tall without its pedestal. Foundations were built as a system of reinforced concrete columns and slabs which can be classified as a spatial column-slab system. Actual mechanical parameters of the substrate and of the artificial mound made of field stones, sand, gravel and clay were adopted in calculations. The numerical simulations of structural members of foundation and determination of the stress distribution are presented in the article. Monument itself was not included into the model. Instead of it the rigid cantilever was introduced to which resultant forces were applied. Three different stages were distinguished: the initial state after foundation and mound accomplishment, the initial state plus the dead load and the initial state plus the dead load and the wind load. It was assumed that the wind load was taken into account in a quasi-static formulation by applying the equivalent horizontal force and the torque. Stresses and displacements for these three stages were determined by Finite Element Method using Simulia ABAQUS system. It was disclosed what was a contribution of particular parts of foundations in sustaining loads in considered load cases. The state of exertion of structural members of foundations and the soil itself was assessed. It was showed that the column-slab foundations and soils of the mound play important role in taking loads of the statue, spreading them and safe transferring to the undisturbed level of natural soils. According to the numerical simulations results the columns of foundation take as much as 64% of the vertical load (in the most unfavourable load conditions). At the same time soils of the mound take through the side surface of piles about 20 % of the vertical load.The paper presents results of numerical simulations of the stress distribution and deformations within of foundations of huge monument of Christ The King erected in Świebodzin (Poland) in 2010. It is 3 meters taller than the better known statue of Christ the Redeemer in Rio de Janeiro, standing at 30.1 meters tall without its pedestal. Foundations were built as a system of reinforced concrete columns and slabs which can be classified as a spatial column-slab system. Actual mechanical parameters of the substrate and of the artificial mound made of field stones, sand, gravel and clay were adopted in calculations. The numerical simulations of structural members of foundation and determination of the stress distribution are presented in the article. Monument itself was not included into the model. Instead of it the rigid cantilever was introduced to which resultant forces were applied. Three different stages were distinguished: the initial state after foundation and mound accomplishment, the initial state plus the dead load and the initial state plus the dead load and the wind load. It was assumed that the wind load was taken into account in a quasi-static formulation by applying the equivalent horizontal force and the torque. Stresses and displacements for these three stages were determined by Finite Element Method using Simulia ABAQUS system. It was disclosed what was a contribution of particular parts of foundations in sustaining loads in considered load cases. The state of exertion of structural members of foundations and the soil itself was assessed. It was showed that the column-slab foundations and soils of the mound play important role in taking loads of the statue, spreading them and safe transferring to the undisturbed level of natural soils. According to the numerical simulations results the columns of foundation take as much as 64% of the vertical load (in the most unfavourable load conditions). At the same time soils of the mound take through the side surface of piles about 20 % of the vertical load

Planning the scope of repair of the inner cover of an industrial chimney based on thermal imaging studies

Badania termowizyjne znajdują szerokie zastosowanie w medycynie i technice. W pracy zaprezentowano przykład wykorzystania kamery termowizyjnej do oszacowania zakresu napraw wewnętrznych ceramicznych powłok izolacyjnych w żelbetowym kominie przemysłowym. Eksploatowany komin odprowadza gazy spalinowe o wysokiej temperaturze, w efekcie czego rozgrzewa się zarówno powłoka izolacyjna, jak i żelbetowy trzon komina. Termogramy wykonane kamerą termowizyjną od strony zewnętrznej pozwalają odkryć miejsca uszkodzeń powłoki izolacyjnej oraz ewentualne mostki cieplne. Staranny skaning całej powierzchni komina stwarza możliwość oszacowania zakresu ewentualnych napraw powłoki izolacyjnej. Wyniki przykładowych badań termowizyjnych komina przedstawione w artykule potwierdzają przydatność tej metody do detekcji uszkodzeń powłoki izolacyjnej i prognozowania zakresu remontu. Precyzyjne ustalenie zakresu remontu komina odbywa się metodami wizualnymi bezpośrednio lub za pośrednictwem kamer z drona, po wyłączeniu komina.Thermographic research is widely used in medicine and technology. The paper presents an example of using a thermal imaging camera to estimate the scope of internal repairs, ceramic insulating coatings in a reinforced concrete industrial chimney. The operated chimney discharges exhaust gases at high temperatures, as a result, both the insulating shell and the reinforced concrete shaft of the chimney heats up. Thermograms made with a thermal imaging camera from the outside reveal the places of damage to the insulation coating and possible thermal bridges. Detailed scanning of the entire surface of the chimney makes it possible to estimate the scope of possible repairs of the insulation coating. The results of the exemplary thermal imaging tests of the chimney presented in the article confirm the usefulness of this method for detecting damage to the insulation coating and forecasting the scope of renovation. Precise determination of the scope of the chimney renovation is carried out by visual methods, directly or via cameras from the drone, after shutting down the chimney

Changes in the Strength of the Polymer Concrete Used in the Electroplating Vats Under Operational Load

Due to the strong and aggressive electrolyte media and thermal load, design of the electroplating vats in the copper industry often relies on the resin concrete. The article presents the results of the strength tests of the polymer concrete based on the "Derakane" resin, used in the construction of electroplating vats. Samples were taken from the real vats - both new and 17-year old. Strength tests included compression and bending tensile strength test. To assess the effect of operational conditions the tests were performed on the same-age vats, some of which were never used while others were subjected to the operational load. During the operation, the vats sustained load of the anode and cathode weights, cyclic electrolyte loading with a temperatures up to 60°C. As a result, it was noted that the operational conditions led to the increased strength of the polymer concrete material

Buckling Resistance of Two-Segment Stepped Steel Columns

Columns of stepwise variable bending stiffness are encountered in the engineering practice quite often. Two different load cases can be distinguished: firstly, the axial force acting only at the end of the column; secondly, besides the force acting at the end, the additional force acting at the place where the section changes suddenly. Expressions for critical forces for these two cases of loading are required to correctly design such columns. Analytical formulae defining critical forces for pin-ended columns are derived and presented in the paper. Derivations were based on the Euler-Bernoulli theory of beams. The energetic criterion of Timoshenko was adopted as the buckling criterion. Both formulae were derived in the form of Rayleigh quotients using the Mathematica® system. The correctness of formulae was verified based on one the of transcendental equations derived from differential equations of stability and presented by Volmir. Comparisons to results obtained by other authors were presented, as well. The derived formulae on the critical forces can be directly used by designers in procedures leading to the column’s buckling resistance assessment. The relatively simple procedure leading to buckling resistance assessment of steel stepped columns and based on general Ayrton-Perry approach was proposed in this work. The series of experimental tests made on steel, stepped columns and numerical simulations have confirmed the correctness of the presented approach

Dynamic Behavior of A High-Rise Building Under Seismic Loads for Different Bearing Frame Types

Paper presents the results of dynamic behavior analysis of a high-rise building under seismic loads as part of the “base-foundation-building” system. Analysis covers different types of reinforced concrete construction with girder frame and non-girder frame. Using modal analysis, paper presents differences in mode shapes and frequencies caused by the presence or absence of girders. Paper also demonstrates variations in the stress-strain state for the vertical bearing structures under the seismic load for different frame types

Numerical Simulations of Destructive Tests of Cast Iron Columns Strengthened with a CFRP Coating

In many cases, there is a need to reinforce the existing, sometimes very old, cast iron columns. The paper describes a proposed and completed reinforcement procedure using an external, thin coating (sleeve or jacket) made of composite (carbon fiber reinforced polymer—CFRP). The strengthening effect was verified in destructive tests performed on two original columns (without reinforcement) and two other, identical columns strengthened by means of the proposed technique. Due to the expected very high load capacity of the axially loaded column, the test rig was designed to allow the application of the force on a big eccentricity. For this purpose a special base was designed and fabricated. Destructive tests have confirmed the high effectiveness of the adopted strengthening technique. The main objective of the present paper is a numerical confirmation of experimental results. All material parameters required in the numerical model were determined in laboratory tests. Simulation was performed using the finite element method—based on two systems, COSMOS/M and Simulia Abaqus. Numerical models were validated on results of the analytical assessment of stresses presented in the paper as well. Results of numerical simulations made on nonlinear models were compared with the experimental results. Destruction mechanisms observed in the experiments were confirmed in performed numerical simulations