bluuebunny/crossref_metadata_2025_split huggingface dataset:
Damping Identification and Prediction for Laminated Composite Plates
Authors: Wesolowski M , Barkanov E 
Published: December 2019

Abstract
Laminate composite structures are widely used in different sectors of industry due to their remarkable stiffness and damping performance. The present study focuses on the damping identification and prediction for laminated composite plates. The damping model based on the strain energy method was used for damping coefficients identification and for modal loss factor prediction. The study concerns with the damping coefficients identification for a single layer of an unidirectionally laminated plate. The reliability of the proposed identification method is validated by numerical modal loss factor prediction for a plate made of the layers in question but having different geometric characteristics. Further, the predictions of the modal loss factors were also validated by a vibration test. All the vibration tests necessary for the current study were performed in a non contact manner using laser vibrometer. The results delivered from the identification method were proven to be credible for modal loss factor prediction.
Lamina properties non-destructive characterisation of asymmetric carbon fiber reinforced laminates
Authors: Namsone E , Ermakov D 
Published: December 2019

Abstract
A non-destructive technique – numerical-experimental method, based on vibration tests is applied for the characterization of lamina properties of asymmetric carbon fiber reinforced laminates. The main idea of this procedure is the determination of simple mathematical models (response surfaces), using the finite element analysis at the reference points of experimental design. Therefore, a significant reduction of computational efforts can be attained. For the purpose of characterization, two asymmetric carbon fiber laminated specimens were prepared, using the prepreg manual layout technology. To evaluate the elastic material properties obtained, the numerical resonant frequency, determinated by using identified material properties, were successfully compared with experimentally measured and high accuracy with average relative error less than 1% was reached.
Numerical Comparison of HPFRC and HPC Ribbed Slabs
Authors: Buka-Vaivade K , Sliseris J , Serdjuks D , Sahmenko G , Pakrastins L 
Published: December 2019

Abstract
The problem of limited resources is actual nowadays. One of the ways for solving this problem can be the use of high-performance fiber reinforced concrete as a structural material for elements subjected to the flexure. The dispersive reinforcement improves the properties of the concrete and allows reducing the required dimensions of cross-section and ratio of longitudinal reinforcement for members subjected to flexure. This research includes the numerical comparison of ultimate limit state and serviceability limit state of ribbed slabs from high-performance concrete (HPC) and high-performance fiber reinforced concrete (HPFRC) behavior, considering the different deformative properties of these materials. The effective use of these materials has been studied using a nonlinear finite element model. This model is created by using a beam type element with a multilayer cross-section, where each layer has a non-linear stress-strain relationship, according to the layer materials such as HPC, HPFRC, or steel bars. The finite element model used for the limited plates is validated. Results of experiment showed, that used calculation model describes with sufficient accuracy the behaviour of the ribbed slabs. The difference between design and experimentally determined breaking load is less than 6% for ribbed slab. The use of HPFRC for ribbed slabs with the spans from 6 to 12 m is justified so as using of HPFRC instead of HPC enables to increase 42-46% the intensity uniformly distributed load for the ribbed slabs with the same cross-sections and allowed deflections.
Self-healing concrete with crystalline admixture – a review
Authors: Guzlena S , Sakale G 
Published: December 2019

Abstract
Concrete is the most used construction material for years. However long term serviceability is an issue, when we focus on sustainable building and use of materials. In long term service different types of visual and structural defects can appear in concrete structures. Defects in material enhances due to aggressive factors in outdoor (chlorides, sulphides and carbonates, freeze-thaw) which reduces material properties over a longer period. Mainly defects on visible surfaces of structures are from mechanical impacts, environmental exposure or due to impropriate maintenance. There are methods to reduce the risks and improve service life. One of them is self-healing materials, like bacteria, crystalline additives, in-capsulated healing agents and other. Use of self-healing material has preference, like lower maintenance costs for inspection, monitoring and complicated repair. Crystalline admixtures have several advantages comparing to other self-healing techniques, like improved concrete water tightness, no need for encapsulation before addition to concrete mix, which reduces sample preparation time.
Shear Failure of Sandwich Panels Subjected in Bending
Authors: Daugevičius M , Skuturna T , Valivonis J , Patapavičius A 
Published: December 2019

Abstract
The paper describes the behaviour of the sandwich panels in bending. Two panels of the same dimensions are tested. The panels differ only in the layout of the inner thermal insulation layer. The thermal insulation layer is made of separate mineral wool slabs. The graphs of the strain development in the external sheets, the displacement between the layers and mid-span displacement are presented in the paper. The nature of the failure shows that only separate internal thermal insulation slabs resist the shear force. Therefore, the complete width resistance cannot be evaluated. The views of the failure are also presented.
Parametric identification of multy-storey building model based on oscillation testing results
Authors: Volkova V , Gaile L , Pakrastins L 
Published: December 2019

Abstract
Buildings and structures are complex systems having predetermined parameters, which should be controlled in the process of manufacturing structures, construction and installation. In some cases, oscillations are the most dangerous effects on the buildings and structures. Significant alternate stresses caused by oscillational actions leads to accumulation of damage in the material. It causes the appearance of fatigue cracks and destruction. In addition to fatigue failure in mechanical systems there are other phenomena that cause changes in the structure of the surface layers of the parts to be joined and consequently the reduction of the frictional force in the joint. The object of the study is a multi-storey building having a rectangular shape in plane. Structural scheme of the building is a two spans frame. The frame of the building consists of monolithic reinforced concrete structures. According to the analysis of the basic diagnostic parameters of the technical condition of buildings and structures, affect their stability and reliability are geometrical parameters of buildings and structures, and their main structural elements, as well as physical and mechanical parameters of structural elements of building and dynamic parameters of buildings and structures. An analysis of methods for determining the dynamic parameters of buildings has shown that the main criteria for assessing the technical condition of bearing structures, using the dynamic method, is the period and frequency building oscillation. Dynamic tests were conducted to determine the dynamic and rigid characteristics of bearing structural elements of the building and structures, detection of hidden defects. According to the method of measuring the dynamic parameters, the degree of damage to a building or structure, is determined by the comparison of the design values of dynamic parameters, periods of eigenoscillations, and the decrement of oscillations with experimentally obtained data.
Numerical Modelling of High Strength Fibre-Concrete’s columns in Multi-Storey Building
Authors: Sliseris J , Buka-Vaivade K 
Published: December 2019

Abstract
The complexity of architecture is continuously growing. Therefore, it is necessary to develop a new construction system with complicated topology using less human work. A fibre-concrete is very promising material to solve those problems. However, design methods of fibre-concrete load bearing structures such as columns are not well developed. Therefore, a new numerical simulation framework is proposed for analysis of fibre-concrete structures macro scale. The method can take into account non-linear post-cracking behaviour of fibre concrete. This includes local fibre orientation in thin elements, anisotropic continuum damage models on different scales, efficient meso-scale fibre orientation prediction tools and others. The proposed method is used to analyse building’s columns where part of structural elements is made from fibre-concrete. The effectiveness of fibre-concrete is estimated and proposed a guideline for optimal design using fibre-concrete.
Characterization of crack formation and development in the oil&gas well casing cement sheath
Authors: Paegle I , Marcos-Meson V , Fischer G 
Published: December 2019

Abstract
The oil industry relies on the use of cement as a primary barrier, to isolate the steel casing from the surrounding formations and provide overall stability on the bored structure. There has been extensive technological development on the physical and mechanical properties of the materials from the cement and cementing industry, in order to produce and install effective cement barriers, capable of withstanding both physical and chemical loads under extreme wellbore conditions. In particular, the formation of cracks and interfacial damage at the primary cement sheath is a largely discussed issue. However, there is still a limited understanding about the crack formation and propagation processes in well-cements, due to the particular geometric and boundary conditions of the structural system, such as: pressure, temperature, and confinement conditions. This paper is focused on the crack formation and propagation processes on cement systems under wellbore-like geometrical conditions, and proposes a test-setup to evaluate cracking and localized damage at the casing-cement interface.
Use of Artificial Neural Network for Initial design of steel structures
Authors: Mote H , Satish Kumar S R 
Published: December 2019

Abstract
Design of steel structures is an iterative process that often turns complicated when requires initial guess. A good initial design guess that comes from past design experience can considerably reduce the number of subsequent analysis and design cycles. It is difficult to form declarative rules to express human intuitions and past experience. Another problem in design process is arriving at optimal solution, where optimization process in most cases is computationally expensive and time consuming. Artificial Neural Network (ANN) is a promising computational model that can perform cognitive tasks, such as learning and optimization. This paper focuses on application of ANN in design so as to make design process more efficient. The aim is to train ANN to arrive at optimal solution by considering design constraints along with practical. This is illustrated with an example of design of compression member which primarily requires initial guess. The economy in design is tried to obtain by providing training set of optimal solutions to a multilayer neural network. The design process followed to generate training set is in accordance with IS: 800-2007. The solutions given by ANN are approximate but have reasonable agreement with the expected solutions.
Development of a high clay content earth plaster
Authors: Lagouin M , Laborel-Préneron A , Magniont C , Aubert J-E 
Published: December 2019

Abstract
Earth, as a building material, offers many advantages: on an ecological point of view, it is a natural, abundant, recyclable material with low energy used for production and transportation. Moreover, earth is known to be a natural humidity regulator and to improve comfort inside buildings, making it a good choice for indoor plastering. The clayey phase gives the global cohesion of the material by acting as a binder for the sand grain skeleton. The finest grain soil fraction is responsible for the dry strength, the water vapour permeability and the sorption capacity of earthen plasters. However, clay also induces the drying shrinkage of the mortar leading to the cracking of the plaster. The objective of this work is to improve the moisture buffer capacity of earthen plaster by increasing its clay content without jeopardizing the general behaviour of plasters. Based on consistency, shrinkage and shear tests, the characteristics of mortars in fresh and hardened states were evaluated. The hygric regulator potential of earthen materials were measured through the Moisture Buffer Value (MBV) test. As expected, results have shown that, to maintain a standard level of consistency, an increase in the clay content leads to a greater amount of mixing water. Moreover, to enhance the MBV, the highest possible earth content must be used. Addition of organic admixtures can be considered to improve the high-clay content plaster behaviour without jeopardizing the aesthetic and mechanical aspects of plaster.
Experimental assessment of bio-based earth bricks durability
Authors: Laborel-Préneron A , Giroudon M , Aubert J E , Magniont C , Faria P 
Published: December 2019

Abstract
Construction is one of the most polluting industrial sectors, that is the reason why developing sustainable building materials is a world-wide interest. Earth bricks have recently been more and more studied, mainly regarding their mechanical and hygrothermal properties. The interest in adding plant aggregates to an earth matrix, notably to improve the thermal behaviour, has also been shown. However, durability of the materials is a major concern to sustain performance levels, to limit maintenance and to ensure the comfort and safety of the occupants. Although earth construction seems to be durable, with the various examples of the vernacular heritage in France and all over the world, unstabilised earth is quite sensitive to environmental factors (weather, occupants, micro-organisms). The resistance of an earthen material to liquid water is particularly low, and the addition of plant fibres may decrease its resistance even more. Moreover, the incorporation of organic matter, containing cellulose, raises questions about the composite resistance to moulds. Investigations are thus needed to assess several durability properties. The present paper studies and compares durability of earth bricks containing 0% and 3% weight content of barley straw, lavender straw and rice husk. Some durability tests corresponding to weathering or occupants’ actions are conducted: a wet erosion test is performed to simulate rain or accidental water droplets and the resistances to dry abrasion and to impact are also appraised. The resistance to fungal growth is also investigated. Results show a considerable interest in adding lavender straw in earth bricks. Indeed, a very good compromise has been found concerning properties of weathering durability and to microorganisms. The addition of lavender straw improves the dry abrasion resistance of earth bricks whereas rice husk and barley straw additions decrease it. The two types of straw greatly increase the resistance to wet erosion of earth bricks while rice husk only in a smaller extent. Concerning the brick resistance to impact, its behaviour is considerably improved by the addition of the three kinds of plant aggregates, particularly rice husk. Finally, as expected, the bricks made of earth alone are the more resistant to fungal growth. However, the addition of rice husk maintains a very high resistance with the first mould observed after only 10 weeks of incubation at 93% of relative humidity and 30°C.
Calorimetric Investigation of Two Factors Influencing the Maximum Storage Capacity of Calcium Chloride Hexahydrate
Authors: Schmit H , Rudaleviciene D , Rathgeber C , Hiebler S 
Published: December 2019

Abstract
CaCl2·6H2O is a salt hydrate that is attractive as phase change material (PCM). However, in literature, different values are indicated for its melting enthalpy. Here, two possible influence factors on the maximum storage capacity of CaCl2·6H2O are investigated via differential scanning calorimetry (DSC): deviations of the water content from the stoichiometrically correct concentration and different basic raw materials used in the preparation process. While both influence factors are found to have a considerable impact on the maximum storage capacity of CaCl2·6H2O, the influence of deviations of the water content is more important than that of the basic raw materials.
Control of geometrical parameters of a single layer at additive forming of products by FDM technology
Authors: Grechukhin A N , Kuts V V , Oleshitsky A V 
Published: December 2019

Abstract
Questions are considered about the accuracy of the formation of the surface layer by additive methods. The analysis of works is carried out on a research subject. High values of the error of forming (approximation) are revealed at forming of surfaces of a complex profile by additive methods. The spatial orientation of a single layer is proposed to reduce the error of forming products by additive methods . Mathematical dependences are proposed to determine the value of the parameters of a single directed layer on the results of experimental studies.
Information-measuring system to improve the quality of motion control robot manipulators
Authors: Goryanina K I , Katin O I , Vernezi M A , Donskoy D Yu , Tregubenko L A , Chiem N X 
Published: December 2019

Abstract
The use of robotic systems consisting of mechanical manipulators and control systems is now widely used not only in industrial production, but also in medicine, sorting and even in everyday life and services. In recent years, the market of service robotics has been actively developing. Successful implementation of automation systems depends on solving complex scientific and technical problems primarily in the following areas: machine vision, sensor networks, navigation systems. Of particular importance is the task of increasing the accuracy of manipulation. The article proposes a variant of the formation of information-measuring system of the robot manipulator based on MEMS sensors. And also recommendations on the choice of sensors of the sensor system to control the manipulation system of the robot are given.
Analysis of the possibility of levitation of ferromagnetic bodies in a static magnetic field
Authors: Vernezi M A , Goryanina K I , Katin O I , Donskoy D Yu , Lukyanov A D , Tooraj A N 
Published: December 2019

Abstract
The hypothesis of the existence of three-dimensional regions near the sources of the magnetic field, in which it is possible to obtain a stable position of the magnetic object in a stationary field. The hypothesis is based on the existence of two types of points: points with zero field level and points with local extremum of this field. The obtained distributions of magnetic forces act stabilizing on the object under study, in particular, create the effect of levitation of ferromagnetic bodies in the gravitational field of the Earth. Examples of configurations of the field sources that generate many such points. Systems of current windings providing creation of one-and two-dimensional configurations of areas near sources within which magnetic levitation is possible are analyzed.
The study of the use of multi-disc safety friction clutches in the working bodies of crank presses
Authors: Kobzev K O , Bozhko E S , Mozgovoi A V , Kostromina E I , Babenko L G 
Published: December 2019

Abstract
Studies of safety couplings have shown that when the friction forces in splined joints of friction disks and half couplings are taken into account, the moment of friction of the clutch increases compared to the moment calculated without taking these forces into account. Among the safety clutches, friction clutches occupy a special place in use in crank presses due to the increased accuracy of limiting the transmitted load. This allows you to increase the efficiency of protection of parts and drive units of machines, as well as reduce their weight and dimensions.
Friction disks are pressed against each other with the force created by the spring, and the moment of friction arising between them ensures the connection of the leading parts with the followers. The friction force in the slots significantly reduces the transmitted force of pressing on subsequent disks, but its influence is not taken into account in existing studies.
Objectives of increase of capacity and lifetime of municipal solid waste dump according to density index study
Authors: Larin D , Staseva E , Khetsuriani E 
Published: December 2019

Abstract
The problem of the optimal waste management of industrial and household waste is extremely important due to large amount of accumulated and annually produced waste. One of the crucial aims to improve ecological quality and environmental safety and compliance is to improve efficiency of waste management. The vast majority of solid domestic waste landfills are used up, but design, construction and place new territories into operation for receiving and waste disposal will take 3-5 years. In this work, issues of definition of the residual capacity of landfill are considered, aiming to expand the capacity and usage period, based on the solid landfill body density index research. Study object is solid household waste landfills in Rostov region, study subject is anthropogenic filling layers of the landfill. In order to support business objectives, there was conducted engineering and geological research, wells were drilled, laboratory studies were undertaken and soil tests were analyzed. Experimental results show the possibility to continue waste disposal works in the current landfill by means of increase of waste density index and free geometric scope.
Reconstruction of electromechanical device for blocking dust emissions
Authors: Minkin M S , Kuimov D N 
Published: December 2019

Abstract
As a result of the work, a new configuration of the electrode system was investigated based on the application of the particle behavior prediction method. The new configuration of the electrode system allows for a lower supply voltage to increase the bulk density of the electric field charge in the interelectrode space, to increase the time of the dust particle in the interelectrode space, and also reduces the risk of electrical discharges on the corona electrodes. Calculation on the developed special software product was made for different geometry of the interelectrode window (120,150,200 microns). Computer simulation of physical processes in the interelectrode space, analysis of the dynamics of the charge set by the dust particle, as well as calculation of the forces acting on the dust particle confirmed the efficiency of the chosen geometry of the electrode system.
Modeling the mechanical characteristics of tribotechnical composites
Authors: Suvorova T V , Belyak O A , Ivanochkin P G , Danilchenko S A 
Published: December 2019

AbstractSome aspects of creating composite materials with a modified matrix based on aromatic polyamide phenylone FS-2 are considered. The effective characteristics of the composites are calculated on the basis of the self-consistency method and compared with experimental data obtained by the nanoindentation method. The stress-strain state of the composite during tribological contact was investigated on the basis of the contact problem of the motion