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Wyniki wyszukiwania dla: current transducers
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Current divider-based nanosecond high current pulse measuring systems
PublikacjaThis paper presents the analysis of the new approach to the measurement methodology of significant values (in order of hundreds of kA) and huge steepness (in order of MA/μs) current pulses based on current dividers along with a comparison of the various types transducers suitability in measuring systems with such extreme parameters. Such dividers are used to extend the measurement ranges of current transducers with limited current...
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Indirect Measurement of Motor Current Derivatives in PMSM Sensorless Drives
PublikacjaMotor current derivatives contain useful information for control algorithms, especially in sensorless electric drives. The measurement of motor current derivatives in electric motors supplied by voltage source inverter can be performed using di/dt transducers. However, in such a solution additional sensors have to be installed, e.g. Rogowski coils. Another approach is to measure current derivatives indirectly – by oversampling...
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Damage detection in plates based on Lamb wavefront shape reconstruction
PublikacjaMany of the current studies in the area of damage detection using elastic wave propagation are based on deploying sensor networks with a large number of piezoelectric transducers to detect small-size cracks. A major limitation of these studies is that cracks are usually larger and have different shapes in real cases. Moreover, using a large number of sensing nodes for damage detection is both costly and computationally intensive....
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Evaluation of expanded uncertainty of instantaneous power measurement in a bearing diagnostic system.
PublikacjaThe paper presents the issues concerning the estimation of the expanded uncertainty in the system for the diagnosis of rolling bearings, consisting of transducers: voltage and current voltage, which is used for diagnostic bearing motors method based on the measurement and analysis of the instantaneous power signal consumed by the induction motor. It presents the methodology for assessing the measurement uncertainty and presents...
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Space vector modulation in multilevel inverters of the servo drives of the trajectory measurements telescopes
PublikacjaUsing the MatLab/Simulink mathematical model of a three-phase three-level voltage inverter, the influence of the space-vector modulation (SVM) algorithm on the pulsations of the current (torque) of an AC motor in the range of low rotation speeds is considered. It is shown that the SVM of the second kind does not provide a pulsations level comparable to the pulsations of a sinusoidal pulse-width modulation (SPWM), both in the static...
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Application of Maximum-Length Sequences to impulse response measurement of hydroacoustic communications systems
PublikacjaThere is a growing interest in digital transmission of telemetry data on ultrasonic waves. The dependence of signal attenuation on squared frequency, specific to the hy-droacoustic systems, induces problems that do not exist in monochromatic, narrowband radio communications systems. For adapting the transmission parameters to current propagation conditions, a precise knowledge of instantaneous changes of channel performances is...
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Finite Element Method Applied in Electromagnetic NDTE: - A Review
PublikacjaThe paper contains an original comprehensive review of finite element analysis (FEA) applied by researchers to calibrate and improve existing and developing electromagnetic non-destructive testing and evaluation techniques, including but not limited to magnetic flux leakage (MFL), eddy current testing, electromagnetic-acoustic transducers (EMATs). Premium is put on the detection and modelling of magnetic field, as the vast majority...
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Koncepcja zdalnego sterowania i monitoringu urządzeń trakcyjnych z wykorzystaniem technologii teleinformatycznych
PublikacjaAdvancement in wireless communication enables engineers to apply sophisticated and relatively inexpensive technologies in new fields of industry, which were previously designated solely to wire-based solutions. One of those fields is railway transportation system. In effect of a high reliability and safety demands, this area was resistive to new technologies. Nowadays, increased security and reliability of wireless sensor networks...
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Elastic wave propagation signals in concrete cube (experimental and calculated using discrete element method)
Dane BadawczeThe DataSet contains the results of the elastic wave propagation. Both experimental and numerical signals were obtained for the concrete cube with dimensions of 50 × 50 × 50 mm3. The specimen was made of concrete with called mortar concrete. The ingredients of the concrete mix were as follows: CEM I 42.5R (500 kg/m3), sand 0 – 2 (1500 kg/m3) and water...
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Estimation of the uncertainty of the AC/AC transducer output voltage
PublikacjaThe paper presents a methodology for estimating uncertainty of voltage transducers processing function, on the example of CYVS411D07 voltage transducers. The analysis was conducted using the method based on the GUM Guide propagation of uncertainty law and the determination of the coverage factor based on the effective number of degrees of freedom (t-Student distribution). The paper also presents example evaluation results of measured...
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White light thermoplasmonic activated gold nanorod arrays enable the photo-thermal disinfection of medical tools from bacterial contamination
PublikacjaThe outspread of bacterial pathogens causing severe infections and spreading rapidly, especially among hospitalized patients, is worrying and represents a global public health issue. Current disinfection techniques are becoming insufficient to counteract the spread of these pathogens because they carry multiple antibiotic-resistance genes. For this reason, a constant need exists for new technological solutions that rely on physical...
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Guided wave propagation signals measured on corroded stiffened panels
Dane BadawczeThe fundamental antisymmetric Lamb mode was excited by piezoelectric transducers attached at the pre-selected points on stiffened panels, representing typical structural ship components. The specimens were exposed to accelerated marine corrosion degradation, so the signals were collected to analyze the influence of the degree of degradation on the wave...
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Detection and size estimation of crack in plate based on guided wave propagation
PublikacjaThe paper presents results of the comprehensive theoretical and experimental investigation of crack detection in metallic plate using guided wave propagation. The main aim of the paper is to develop the novel method which would allow for linear crack size estimation with the use of minimal number of the transducers. In general, there exists the relation between length of the propagation path and the wave amplitude value. However,...
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A tool for designing water tanks for measuring hydroacoustic transducers
PublikacjaSpecial water tanks are commonly used to measure the parameters of underwater acoustic systems. They must meet specific requirements, the fulfilment of which ensures very small but acceptable measurement errors. These requirements define the size of the tank and its shape as well as the strong attenuation of reflected waves. At the design stage, it is necessary to determine the impact of the tank structure on the measurement errors...
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Development and Assessment of Regeneration Methods for Peptide-Based QCM Biosensors in VOCs Analysis Applications
PublikacjaCleaning a quartz crystal microbalance (QCM) plays a crucial role in the regeneration of its biosensors for reuse. Imprecise removal of a receptor layer from a transducer’s surface can lead to unsteady operation during measurements. This article compares three approaches to regeneration of the piezoelectric transducers using the electrochemical, oxygen plasma and Piranha solution methods. Optimization of the cleaning method allowed...
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Monitoring Steel Bolted Joints during a Monotonic Tensile Test Using Linear and Nonlinear Lamb Wave Methods: A Feasibility Study
PublikacjaThe structural integrity of steel bolted joints may be compromised due to excessive loading. Therefore, condition assessment and the detection of potential defects before they cause a failure have become a major issue. The paper is focused on the condition monitoring of a bolted lap joint subjected to progressive degradation in a tensile test. The inspection used Lamb waves propagated through the overlap area. Wave propagation...
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Comparison of active proximity radars for the wearable devices
PublikacjaTwo methods of object position and movement estimation in relation to the user of smart glasses were investigated. An active infrared and ultrasonic methods of the obstacle detection were presented and compared. Application of these methods depend on active transducers type (physical medium used), geometry and surface properties of detected objects and their movement direction and speed. In the article properties of both detectors...
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Ultrasonic wave propagation and digital image correlation measurements of steel bars under 3-point bending
Dane BadawczeThe DataSet contains the results of the mechanical behaviour of a bar under a 3-point bending test. The bar was made of steel and had a cross-section of 5.96 × 5.96 mm2 and a length of 200 mm. The three-point bending test was performed using a Zwick/Roell Z10 universal testing machine (UTM), with a distance between supports of 12 cm. The parameters...
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GUIDED WAVES IN SHIP STRUCTURAL HEALTH MONITORING – A FEASIBILITY STUDY
PublikacjaShips and offshore structures operate in a severe corrosion degradation environment and face difficulty in providing long- lasting corrosion protection. The Classification Societies recommend regular thickness measurements leading to structural component replacements, to ensure structural integrity during service life. The measurements are usually performed using ultrasonic thickness gauges and such an approach requires multiple...
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Numerical modeling of sound intensity distributions around acoustic transducer
PublikacjaThe aim of this research study is to measure, simulate and compare sound intensity distribution generated by the acoustic transducers of the loudspeaker. The comparison of the gathered data allows for validating the numerical model of the acoustic radiation. An accurate model of a sound source is necessary in mathematical modeling of the sound field distribution near the scattering obstacles. An example of such obstacle is a human...
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Intergranular Corrosion Detection Using Electromagnetic Transducers for Ultrasonic Testing
PublikacjaThe aim of this paper is to create a research methodology that allows a quick analysis of the structural state of high alloy austenitic steels using non-destructive ultrasonic tests, in contrast to destructive standard methods. Electromagnetic acoustic transducers (EMAT) are used to generate and receive the ultrasonic wave and detect the microstructural changes caused by sample sensitization in elevated temperature, even after...
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Research on assessment of bolted joint state using elastic wave propagation
PublikacjaThe work contains results of experimental investigation of elastic wave propagation in a bolted single-lap joint. Tests were carried out for the excitation perpendicular to the connection plane. In experimental studies, PZT transducers were used for both excitation and registration of ultrasonic waves. The analyses took into account varying contact conditions between the elements of the connection depending on the value of the...
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Experimental study on ultrasonic monitoring of splitting failure in reinforced concrete
PublikacjaThis paper investigates inspection of reinforced concrete elements sensitive to the splitting failure. The behaviour of a reinforced concrete specimen subjected to a tensile stress is considered. The damage detection procedure is based on the ultrasonic wave propagation technique. The piezoelectric transducers are located on both ends of the specimen and the measurements are taken periodically during the incrementally increased...
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The Application of Vibration Recording and Analysis in Tribological Research on Sliding Friction
PublikacjaThe paper reports on a tribological research on the macroscopic manifestation and characteristics of sliding friction. The aim of the task was to measure friction in lubricated sliding contacts and test the interactions between the environment (the test rig) and the experimental friction contact. Friction-induced vibrations were observed and studied as a manifestation of the process. The typical set of velocity and force/torque...
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A spice equivalent circuit for modeling the performance of dual frequency echo-sounder
PublikacjaThe paper presents novel network equivalent circuit of piezoceramic circular disc transducers that takes into account thickness and radial mode of vibrations. The starting point of the analysis is 4-port description of circular disc element representing the solution of wave equation set in radial and thickness directions. The approximate solution for harmonic case is represented in the form of 4x4 matrix, which is synthesised and...
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Data recorded for the purpose of the 3D sound intensity visualization around the organ pipe (des sound)
Dane BadawczeThe set contains data recorded using the Cartesian robot and multichannel acoustic vector sensor (from Microflown) for the purpose of the 3D sound intensity visualization of radiated acoustic energy around the organ pipe.
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Examining Acoustic Emission of Engineered Ultrasound Loudspeakers
PublikacjaMeasurement results of the sound emitted from an ultrasound custom-made system with high spatial directivity are presented. The proposed system is using modulated ultrasound waves which demodulate in nonlinear medium resulting in audible sound. The system is aimed at enhancing the users’ personal audio space, therefore the measurements are performed using the Head and Torso Simulator which provides the realistic reproduction of...
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Analysis of wave propagation in a bolted steel joint
PublikacjaThe paper presents results of numerical and experimental investigations of elastic wave propagation in a bolted single-lap joint. The research was carried out for both symmetric and antisymmetric Lamb wave modes. In experimental studies the PZT transducers were used to excite and register wave propagation signals. The controlled value of the torque during measurements was ensured by the use of high precision torque wrenches. Numerical...
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Measurements and Simulations of Engineered Ultrasound Loudspeakers
PublikacjaSimulation and measurement results of the sound emitted from an ultrasound custom-made system with high spatial directivity are presented. The proposed system is using modulated ultrasound waves which demodulate in nonlinear medium resulting in audible sound. The system is aimed at enhancing the users’ personal audio space, therefore the measurements are performed using the Head and Torso Simulator which provides realistic reproduction...
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Elastic wave propapagation in diagnostics of self-drilling system of grouted anchors
PublikacjaThe paper presents an experimental investigation of elastic wave propagation in a self-drilling hollow bar system, which is commonly used in geotechnical industry as the element of grouted ground anchors and soil nails. The single self-drilling hollow bar and self-drilling system of two bars connected by a coupler were considered. Longitudinal waves were excited at one end of the bar and registered at both ends, by means of PZT...
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Implementation of Contemporary Technologies in Naval Sonars Modernization
PublikacjaToday’s fast technological advancement in electronics and signal processing methods makes electronic systems, including sonars, obsolete very quickly. The Polish Navy seems to be particularly affected as its ships were built in the 1970s and 1980s. Researchers at the Gdansk University of Technology have developed a methodology for modernising Navy sonars which involves the use of new electronic sub-systems and modern, bespoke methods...
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Guided wave propagation for assessment of adhesive bonding between steel and concrete
PublikacjaAdhesive bonding is becoming more increasingly important in joining of structural elements. In civil engineering, there is a growing interest in connection by adhesive bonding in steel-concrete flexural members. This study concerns the guided wave propagation technique applied to condition assessment of an adhesive connection between a steel member and a concrete beam. Various states of degradation were considered by producing...
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Preload monitoring in a bolted joint using Lamb wave energy
PublikacjaThe knowledge of the load in prestressed bolted connections is essential for the proper operation and safety of engineering structures. Recently, bolted joints have become an area of intensive research associated with non-destructive diagnostics, in particular in the context of wave propagation techniques. In this paper, a novel procedure of bolt load estimation based on the energy of Lamb wave signals was proposed. Experimental...
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Dynamics of Chains as a Tool to Study Thermomechanical Properties of Proteins.
PublikacjaPolymer dynamics can be formulated on different levels of detail. One approach eliminates microscopic degrees of freedom and a polymer molecule is represented by a simplified structure—a chain. In the simplest case monomers of ideal chain have fixed length, and their orientation is independent of the orientations and positions of neighbouring monomers. This is reason that two monomers can co-exist at the same place. Ideal chain...
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Flow through a prosthetic mechanical aortic valve: Numerical model and experimental study
PublikacjaThis research presents a numerical model dedicated for virtual patient diagnostics in the field of synthetic valve implantation. The model operates based on computational fluid dynamics solver with implemented rigid body motion solver. Characteristic indicators related to the prosthetic valve were determined to assess the correctness of cardiac system operation after implantation. A novel approach for dynamic time discretization...
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Guided waves for monitoring of plate structures with linear cracks of variable length
PublikacjaDamage occurring at the work of plate structures may grow to a considerable size. The joint action – the detection of a defect at the earliest possible stage, the monitoring of its growth and the determination of its critical size in the context of structural reliability allows optimizing the cost of the maintenance and repair of structural elements. Thus the development of monitoring systems for permanent observation of fault...
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Digital signal processing applied to the modernization of Polish Navy sonars
PublikacjaThe article presents the equipment and digital signal processing methods used for modernizing the Polish Navy’s sonars. With the rapid advancement of electronic technologies and digital signal processing methods, electronic systems, including sonars, become obsolete very quickly. In the late 1990s a team of researchers of the Department of Marine Electronics Systems, Faculty of Electronics, Telecommunications and Informatics, Gdansk...
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Lamb wave-based monitoring of shear failure of an adhesive lap joint
PublikacjaThe paper presents a study on the elastic wave propagation in adhesive joints of steel plates subjected to tensile loading. A single lap joint was chosen for analysis because of its simplicity and plurality of applications. Experimental investigations consisted of the uniaxial extension of prepared specimens. Force and displacement values were recorded by a testing machine. Simultaneously, guided Lamb waves were excited and signals...
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Multifrequency Wideband Sonar Array
PublikacjaThis paper describes of new approach to Multifrequency Wideband Arrays (MWA),applied piezocomposite technologies of the array elements. MWA operating in transmitting(Tx) and receiving (Rx) mode on two or three bands, requires state-of-the-art technology andefficient array designing than conventional array in which separate arrays for every band oreven separate Tx and Rx transducers/arrays are used. The new piezocomposite elements...
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Using FreeFEM open software for modelling the vibrations of piezoelectric devices
PublikacjaModelling vibrations of piezoelectric transducers has been a topic discussed in the literature for many decades. The first models - so-called one-dimensional - describe the vibrations only near operating frequency and near its harmonics. Attempts to introduce two-dimensional models were related to the possibility of one transducer working at several frequencies, including both thickness vibrations and those resulting from the transducer...
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Failure Monitoring and Condition Assessment of Steel-Concrete Adhesive Connection Using Ultrasonic Waves
PublikacjaAdhesive bonding is increasingly being incorporated into civil engineering applications. Recently, the use of structural adhesives in steel-concrete composite systems is of particular interest. The aim of the study is an experimental investigation of the damage assessment of the connection between steel and concrete during mechanical degradation. Nine specimens consisted of a concrete cube and two adhesively bonded steel plates...
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Damage detection in a bolted lap joint using guided waves
PublikacjaThe paper presents the experimental investigation of guided waves application to the condition assessment of prestressed bolted connections and a concept of new quantitative indicator. The main goal of the research was the analysis of the influence of the contact conditions changes to the characteristics of a propagating disturbance. The experimental tests were carried out for a single bolted lap joint. The excitation and acquisition...
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Smart acoustic band structures
PublikacjaSmart acoustic band structures exhibit very interesting and non-standard physical properties due to the periodic nature of their certain characteristic on different scale levels. They manifest mostly in their frequency spectra as socalled frequency band-gaps or stop-bands, what has a great impact on the behaviour of these structures in relation to the propagation of vibro-acoustic signals that can be transmitted through the structures...
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A Numerical Study on Baseline-Free Damage Detection Using Frequency Steerable Acoustic Transducers
PublikacjaIn structural health monitoring (SHM) a considerable amount of damage detection algorithms based on guided waves (GW) have been developed. Most of them rely on extensive transducer networks, besides preliminary reference measurements of the structures. This originated a growing demand for hardware simplification and cost reduction of the wave-based SHM methods, driving the conception of new solutions enabling both: the reduction...
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Measurements of drive system properties of the "Magnetic SpeedLine" ultra-fast robot prototype for IML labeling
Dane BadawczeTests of the drive system of the ultra-fast robot "SpeedLine magnetic" for labeling with the IML method were carried out in order to analyze the influence of the operating parameters of the drive system on the correctness and quality of the drive system.
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Data Compression in Ultrasonic Network Communication via Sparse Signal Processing
PublikacjaThis document presents the approach of using compressed sensing in signal encoding and information transferring within a guided wave sensor network, comprised of specially designed frequency steerable acoustic transducers (FSATs). Wave propagation in a damaged plate was simulated using commercial FEM-based software COMSOL. Guided waves were excited by means of FSATs, characterized by the special shape of its electrodes, and modeled...
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Coda wave interferometry in monitoring the fracture process of concrete beams under bending test
PublikacjaEarly detection of damage is necessary for the safe and reliable use of civil engineering structures made of concrete. Recently, the identification of micro-cracks in concrete has become an area of growing interest, especially using wave-based techniques. In this paper, a non-destructive testing approach for the characterization of the fracture process was presented. Experimental tests were made on concrete beams subjected to mechanical...
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Experimental and numerical identification of corrosion degradation of ageing structural components
PublikacjaThe study presents experimental and numerical identification of corrosion degradation of thin-walled structural components employing guided wave propagation. The steel structural components are subjected to through-thickness varying corrosion degradation levels. The developed approach using the non-destructive guided wave-propagation quantifies the equivalent average corrosion degradation level by exploring a limited number of...
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Measurements of ultrasonic bulk and guided wave propagation in additively manufactured cubes and plates obtained by ultrasonic pulse velocity analyzer and scanning laser vibrometry
Dane BadawczeThe DataSet contains the results of measurements of ultrasonic wave propagation in additively manufactured samples made of polylactic acid (PLA). Three types of raster angles in two consecutive layers were assumed: 0°/90° (#1), 45°/-45° (#2) and 90°/90° (#3) with respect to the x-axis. For each printing variants a cubic sample (#C1-3) with dimensions...
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Acoustic emission signals in concrete beams under 3-point bending (beams #1, #2, #3)
Dane BadawczeThe DataSet contains the results of the mechanical behaviour of concrete beams with dimensions 40 x 40 x 160 cm3under the 3-point bending. The beams were made of concrete with the following ingredients: cement CEM I 42.5R (330 kg/m3), aggregate 0/2 mm (710 kg/m3), aggregate 2/8 mm (664 kg/m3), aggregate 8/16 mm (500 kg/m3), water (165 kg/m3) and super-plasticizer...