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In this article, a numerical calibration procedure for undrained cyclic triaxial tests is presented to evaluate the liquefaction potential in sand and silt samples from mining tailings in northern Chile. The numerical modeling of an axisymmetric specimen involved two stages: isotropic consolidation using the Hardening Soil Small (HSS) model and a cycling phase employing the UBC3D-PLM model to simulate the onset of liquefaction using the criterion that the excess pore pressure ratio R u should exceed 0.8. The results demonstrate that the UBC3D-PLM modeling calibrated with experimental data from cyclic triaxial tests effectively represents the excess pore pressure in both sandy and silty soils from mining tailings. The accuracy of the modeling decreases when a single set of parameters is applied to the same soil at different cyclic stress ratios (CSR), highlighting the need for specific calibrations for each loading. [ABSTRACT FROM AUTHOR]

A circular capacitive rainfall sensor can operate from non-touch mode to touch mode; that is, under the action of enough rainwater, its movable electrode plate can form a circular contact area with its fixed electrode plate. Therefore, the weight of rainwater is borne by only its movable electrode plate in non-touch mode operation but by both its movable and fixed electrode plates in touch mode operation, and the total capacitance of its touch mode operation is much larger than that of its non-touch mode operation. Essential to its numerical design and calibration is the ability to predict the deflection shape of its moveable electrode plate to determine its total capacitance. This requires the analytical solution to the fluid–structure interaction problem of its movable electrode plate under rainwater. In our previous work, only the analytical solution for the fluid–structure interaction problem before its movable electrode plate touches its fixed electrode plate was obtained, and how to numerically design and calibrate a circular non-touch mode capacitive rainfall sensor was illustrated. In this paper, the analytical solution for the fluid–structure interaction problem after its movable electrode plate touches its fixed electrode plate is obtained, and how to numerically design and calibrate a circular touch mode capacitive rainfall sensor is illustrated for the first time. The numerical results show that the total capacitance and rainwater volume when the circular capacitive rainfall sensor operates in touch mode is indeed much larger than that when the same circular capacitive rainfall sensor operates in non-touch mode, and that the average increase in the maximum membrane stress per unit rainwater volume when the circular capacitive rainfall sensor operates in touch mode can be about 20 times smaller than that when the same circular capacitive rainfall sensor operates in non-touch mode. This is where the circular touch mode capacitive rainfall sensor excels. [ABSTRACT FROM AUTHOR]

A circular non-touch mode capacitive pressure sensor can operate in both transverse and normal uniform loading modes, but the elastic behavior of its movable electrode plate is different under the two different loading modes, making its input–output analytical relationships between pressure and capacitance different. This suggests that when such a sensor operates, respectively, in transverse and normal uniform loading modes, the theory of its numerical design and calibration is different, in other words, the theory for the transverse uniform loading mode (available in the literature) cannot be used as the theory for the normal uniform loading mode (not yet available in the literature). In this paper, a circular non-touch mode capacitive pressure sensor operating in normal uniform loading mode is considered. The elastic behavior of the movable electrode plate of the sensor under normal uniform loading is analytically solved with the improved governing equations, and the improved analytical solution obtained can be used to mathematically describe the movable electrode plate with larger elastic deflections, in comparison with the existing two analytical solutions in the literature. This provides a larger technical space for developing the circular non-touch mode capacitive pressure sensors used for measuring the static gas pressure (belonging to normal uniform loading). [ABSTRACT FROM AUTHOR]

A circular capacitive rainfall sensor can operate from non-touch mode to touch mode; that is, under the action of enough rainwater, its movable electrode plate can form a circular contact area with its fixed electrode plate. Therefore, the weight of rainwater is borne by only its movable electrode plate in non-touch mode operation but by both its movable and fixed electrode plates in touch mode operation, and the total capacitance of its touch mode operation is much larger than that of its non-touch mode operation. Essential to its numerical design and calibration is the ability to predict the deflection shape of its moveable electrode plate to determine its total capacitance. This requires the analytical solution to the fluid–structure interaction problem of its movable electrode plate under rainwater. In our previous work, only the analytical solution for the fluid–structure interaction problem before its movable electrode plate touches its fixed electrode plate was obtained, and how to numerically design and calibrate a circular non-touch mode capacitive rainfall sensor was illustrated. In this paper, the analytical solution for the fluid–structure interaction problem after its movable electrode plate touches its fixed electrode plate is obtained, and how to numerically design and calibrate a circular touch mode capacitive rainfall sensor is illustrated for the first time. The numerical results show that the total capacitance and rainwater volume when the circular capacitive rainfall sensor operates in touch mode is indeed much larger than that when the same circular capacitive rainfall sensor operates in non-touch mode, and that the average increase in the maximum membrane stress per unit rainwater volume when the circular capacitive rainfall sensor operates in touch mode can be about 20 times smaller than that when the same circular capacitive rainfall sensor operates in non-touch mode. This is where the circular touch mode capacitive rainfall sensor excels.

The design, especially the numerical calibration, of a circular touch mode capacitive pressure sensor is highly dependent on the accuracy of the analytical solution of the contact problem between the circular conductive membrane and the rigid plate of the sensor. In this paper, the plate/membrane contact problem is reformulated using a more accurate in-plane equilibrium equation, and a new and more accurate analytical solution is presented. On this basis, the design and numerical calibration theory for circular touch mode capacitive pressure sensors has been greatly improved and perfected. The analytical relationships of pressure and capacitance are numerically calculated using the new and previous analytical solutions, and the gradually increasing difference between the two numerical calculation results with the gradual increase in the applied pressure is graphically shown. How to use analytical solutions and analytical relationships to design and numerically calibrate a circular touch mode capacitive pressure sensor with a specified pressure detecting range is illustrated in detail. The effect of changing design parameters on capacitance–pressure analytical relationships is comprehensively investigated; thus, the direction of changing design parameters to meet the required or desired range of pressure or capacitance is clarified. [ABSTRACT FROM AUTHOR]

Geotechnical rockmass characterization is a key task for design of underground and open pit excavations. Hydrothermal veins influence excavation performance by contributing to stress-driven rockmass failure. This study investigates the effects of vein orientation and thickness on stiffness and peak strength of laboratory scale specimens under uniaxial and triaxial compression using finite element numerical experiments of sulfide veined mafic igneous complex (CMET) rocks from El Teniente mine, Chile. The initial numerical models are calibrated to and validated against physical laboratory test data using a multi-step calibration procedure, first of the unveined Lac du Bonnet granite to define the model configuration, and second of unveined and veined CMET. Once calibrated, the numerical experiment involves varying the vein geometry in the veined CMET models by orientation (5 to 85°) and thickness (1, 4, 8 mm). This approach enables systematic investigation of any vein geometry without limitations of physical specimen availability or complexity of physical materials. This methodology greatly improves the value of physical laboratory test data with a limited scope of vein characteristics by using calibrated numerical models to investigate the effects of any other vein geometry. In this study, vein orientation and thickness were both found to have a significant impact on the specimen stiffness and peak strength. [ABSTRACT FROM AUTHOR]

Geotechnical rockmass characterization is a key task for design of underground and open pit excavations. Hydrothermal veins influence excavation performance by contributing to stress-driven rockmass failure. This study investigates the effects of vein orientation and thickness on stiffness and peak strength of laboratory scale specimens under uniaxial and triaxial compression using finite element numerical experiments of sulfide veined mafic igneous complex (CMET) rocks from El Teniente mine, Chile. The initial numerical models are calibrated to and validated against physical laboratory test data using a multi-step calibration procedure, first of the unveined Lac du Bonnet granite to define the model configuration, and second of unveined and veined CMET. Once calibrated, the numerical experiment involves varying the vein geometry in the veined CMET models by orientation (5 to 85°) and thickness (1, 4, 8 mm). This approach enables systematic investigation of any vein geometry without limitations of physical specimen availability or complexity of physical materials. This methodology greatly improves the value of physical laboratory test data with a limited scope of vein characteristics by using calibrated numerical models to investigate the effects of any other vein geometry. In this study, vein orientation and thickness were both found to have a significant impact on the specimen stiffness and peak strength.

A circular non-touch mode capacitive pressure sensor can operate in both transverse and normal uniform loading modes, but the elastic behavior of its movable electrode plate is different under the two different loading modes, making its input–output analytical relationships between pressure and capacitance different. This suggests that when such a sensor operates, respectively, in transverse and normal uniform loading modes, the theory of its numerical design and calibration is different, in other words, the theory for the transverse uniform loading mode (available in the literature) cannot be used as the theory for the normal uniform loading mode (not yet available in the literature). In this paper, a circular non-touch mode capacitive pressure sensor operating in normal uniform loading mode is considered. The elastic behavior of the movable electrode plate of the sensor under normal uniform loading is analytically solved with the improved governing equations, and the improved analytical solution obtained can be used to mathematically describe the movable electrode plate with larger elastic deflections, in comparison with the existing two analytical solutions in the literature. This provides a larger technical space for developing the circular non-touch mode capacitive pressure sensors used for measuring the static gas pressure (belonging to normal uniform loading).

The fracture toughness of shale is a key parameter guiding hydraulic fracturing design and optimization. The hollow double-wing slotted (HDWS) specimen is a typical specimen configuration for measuring the mode I fracture toughness of rock. The calibration of the shape factor (f) is the basis for accurately obtaining the fracture toughness of rocks. In this study, the influences of crack length, hole size, and the anisotropy of elastic parameters on f for specimens with three typical bedding orientations—arrester (A), divider (D), and short-transverse (ST) orientations—are systematically investigated using finite element software. The numerical simulation results support the following findings. The mode I f increases monotonically with an increase in hole size. The influence of crack length on f varies depending on hole sizes. Under different bedding orientations, significant anisotropy in f was observed. In addition, the degree of anisotropy in Young's modulus has a major impact on f, which is related to the bedding orientation of the specimen. The apparent shear modulus ratio has relatively little influence on f. As the hole size and crack length increase, the influence of the anisotropy of elastic parameters on f increases. Based on numerical calculations, hydraulic fracturing experiments were conducted on HDWS specimens of Longmaxi shale with three bedding orientations, and the results showed that the peak pressure and fracture toughness of the samples in the ST direction were the lowest, while those in the A direction were the highest. [ABSTRACT FROM AUTHOR]

The seismic performance assessment of heritage architecture presents many challenges due to the restrictions set forth by the conservation principles to protect the associated social and cultural values. These buildings are typically characterized by unreinforced masonry walls connected by tie-rods, vaults, and wooden floors. The era of construction dates to the time when seismic design regulations were largely unknown, making heritage structures potentially vulnerable to earthquake damage. This study presents the seismic performance assessment of the Jesuit College located in the southern part of the Old City of Dubrovnik. A series of field surveys were conducted to qualitatively examine the material composition and obtain geometrical details in part of the Croatian Science Foundation research project IP-2020-02-3531 entitled "Seismic Risk Assessment of Cultural Heritage in Croatia—SeisRICHerCRO". The structural response is thoroughly investigated by means of a complex finite element model calibrated using the frequencies determined from ambient vibration measurements and material characteristics obtained from the literature review of representative cultural heritage buildings. The seismic performance is evaluated using linear static and response spectrum analysis in accordance with Eurocode 8 guidelines for the demand seismic action level. The numerical analysis indicates several structural components in the building exhibiting high shear stress concentration and exceeding the elastic tensile limit under the demand ground acceleration level. The assessment further reveals substantial out-of-plane bending of vulnerable wall components (identified by local mode shapes) at low peak ground acceleration levels. The stress concentration in numerous structural components leads to the identification of vulnerable zones where retrofitting measures are essentially required. [ABSTRACT FROM AUTHOR]

The design, especially the numerical calibration, of a circular touch mode capacitive pressure sensor is highly dependent on the accuracy of the analytical solution of the contact problem between the circular conductive membrane and the rigid plate of the sensor. In this paper, the plate/membrane contact problem is reformulated using a more accurate in-plane equilibrium equation, and a new and more accurate analytical solution is presented. On this basis, the design and numerical calibration theory for circular touch mode capacitive pressure sensors has been greatly improved and perfected. The analytical relationships of pressure and capacitance are numerically calculated using the new and previous analytical solutions, and the gradually increasing difference between the two numerical calculation results with the gradual increase in the applied pressure is graphically shown. How to use analytical solutions and analytical relationships to design and numerically calibrate a circular touch mode capacitive pressure sensor with a specified pressure detecting range is illustrated in detail. The effect of changing design parameters on capacitance–pressure analytical relationships is comprehensively investigated; thus, the direction of changing design parameters to meet the required or desired range of pressure or capacitance is clarified.

There is a demand to calibrate the high-frequency dynamic responses of semi-submersible floating offshore wind turbine (FOWT) induced by the second-order sum-frequency hydrodynamic loads in the numerical model and evaluate its effects on the fatigue damage of the FOWT. A modification approach for the calibration of the high-frequency dynamic responses of FOWT is proposed. In this approach, the effects of the viscous damping and additional restoring force on the second-order sum-frequency quadratic transfer functions (QTFs) are discussed in the frequency domain. The calibrated numerical model (CNM) is obtained with the tuned viscous damping, the second-order sum-frequency QTFs, and the structural damping, based on the measured data from the FOWT model test. The CNM is proved to accurately predict the high-frequency components of the strongly nonlinear responses, namely the pitch motion and tower-top shear force, with the proper prediction of the wave-frequency responses compared with the experimental model under regular wave conditions. The CNM is further applied to predict the high-frequency dynamic responses of the OUCwind under a typical sea state for an operational condition. It is found that the high-frequency component occupies a non-negligible part of the pitch motion, and dominates the tower-top shear force. The linear model (LM) cannot predict and the uncalibrated numerical model (UCNM) underpredicts the high-frequency components of responses. Furthermore, the fatigue damage of the CNM is 14 times greater than that of the LM after a 3 h sea state with a significant wave height of 3 m and a peak period of 6 s. It follows that the large frequency and intensity make the high-frequency tower-top shear force to be a huge risk to the safe operation of the wind turbine, which should attract the industry's concern about the wave-induced high-frequency dynamic responses for the design of FOWTs. • A modification approach for the numerical calibration of the high-frequency dynamic responses of FOWT is proposed. • The modification approach is applied to a numerical model of a novel 10 MW semi-submersible FOWT to calibrate its high-frequency responses based on the experimental results. • The effects of the viscous damping and additional restoring force on the second-order sum-frequency QTF are discussed. • The calibrated numerical model can accurately predict the high-frequency components of the strongly nonlinear responses, based on the proper prediction of the wave-frequency responses. • The effects of the high-frequency tower-top shear force on the fatigue damage of the tower-top section are evaluated. [ABSTRACT FROM AUTHOR]

Asphalt coating is widely utilized for its excellent impermeability on marine structure surface. However, in high latitude regions, the coupling effect of freeze-thaw cycles and chemical aging rapidly diminished the protective effect, significantly increasing the risk of structural damage. Therefore, to maximize the impermeability and durability of asphalt, we homogeneously intermixed the crushed asphalt particles into the concrete instead of surface coating. A series of crushed asphalt particles concrete (CAPC) with different asphalt content were prepared and subjected to up to 30 salt freeze thaw cycles (SFTCs) in a 3.5 wt% NaCl solution. Experimental results revealed that addition of asphalt particles improved pore structure and impermeability, mitigating frost damage and chloride diffusion. Optimal performance is observed at 2 % asphalt content, showcasing a notable 22.0 % reduction in porosity, a substantial 47.3 % decrease in chloride concentration at 10 mm depth after 30 SFTCs, with only a 3 % slight reduction in strength. Moreover, a multi-phase chloride diffusion model was proposed, considering matrix/asphalt damage and time-varying porosity. The influence of aggregate shape and volume, data-processing methods, long-term prediction under different regions were discussed. Compared with asphalt coating and classical concrete, the proposed CAPC is recommended for use under marine environment, especially in cold marine regions. [Display omitted] • Crushed asphalt particles were intermixed into concrete to improve salt frost resistance. • A 2 % asphalt content was proved to be the optimal choice, with good strength and durability. • The diffusion model considered the multi-phase frost damage and time-varying porosity. • The effect of aggregate features and processing method on FEM outcome was studied. • The proposed product is recommended for use under cold marine regions. [ABSTRACT FROM AUTHOR]

The fracture toughness of shale is a key parameter guiding hydraulic fracturing design and optimization. The hollow double-wing slotted (HDWS) specimen is a typical specimen configuration for measuring the mode I fracture toughness of rock. The calibration of the shape factor (f) is the basis for accurately obtaining the fracture toughness of rocks. In this study, the influences of crack length, hole size, and the anisotropy of elastic parameters on f for specimens with three typical bedding orientations—arrester (A), divider (D), and short-transverse (ST) orientations—are systematically investigated using finite element software. The numerical simulation results support the following findings. The mode I f increases monotonically with an increase in hole size. The influence of crack length on f varies depending on hole sizes. Under different bedding orientations, significant anisotropy in f was observed. In addition, the degree of anisotropy in Young’s modulus has a major impact on f, which is related to the bedding orientation of the specimen. The apparent shear modulus ratio has relatively little influence on f. As the hole size and crack length increase, the influence of the anisotropy of elastic parameters on f increases. Based on numerical calculations, hydraulic fracturing experiments were conducted on HDWS specimens of Longmaxi shale with three bedding orientations, and the results showed that the peak pressure and fracture toughness of the samples in the ST direction were the lowest, while those in the A direction were the highest.

Polymer-based conductive membranes play an important role in the development of elastic deflection-based pressure sensors. In this paper, an analytical solution-based method is presented for the design and numerical calibration of polymer conductive membrane-based circular capacitive pressure sensors from non-touch mode of operation to touch mode of operation. The contact problem of a circular membrane in frictionless contact with a rigid flat plate under pressure is analytically solved, and its analytical solution is used for the design of touch mode circular capacitive pressure sensors for the first time. The analytical relationship with input pressure as independent variable and output capacitance as dependent variable is precisely derived and is used for the numerical calibrations of the analytical relationships with input capacitance as the independent variable and output pressure as the dependent variable in order to meet the capacitive pressure sensor mechanism of detecting pressure by measuring capacitance. For the first time, an example showing the design and numerical calibration of a given (given design parameters) polymer conductive membrane-based circular capacitive pressure sensor from non-touch mode of operation to touch mode of operation is provided. Then, the influence of changing several important design parameters on input capacitance–output pressure relationships is comprehensively investigated in order to clarify the desired input–output relationships when changing design parameters. [ABSTRACT FROM AUTHOR]

In this paper, an analytical solution-based method for the design and numerical calibration of polymer conductive membrane-based non-touch mode circular capacitive pressure sensors is presented. The accurate analytical relationship between the capacitance and applied pressure of the sensors is derived by using the analytical solution for the elastic behavior of the circular polymer conductive membranes under pressure. Based on numerical calculations using the accurate analytical relationship and the analytical solution, the analytical relationship between the pressure as output and the capacitance as input, which is necessary to achieve the capacitive pressure sensor mechanism of detecting pressure by measuring capacitance, is accurately established by least-squares data fitting. An example of how to arrive at the design and numerical calibration of a non-touch mode circular capacitive pressure sensor is first given. Then, the influence of changing design parameters such as membrane thickness and Young's modulus of elasticity on input–output relationships is investigated, thus clarifying the direction of approaching the desired input–output relationships by changing design parameters. [ABSTRACT FROM AUTHOR]

In this paper, the three-layer model of ballasted railway track with discrete supports is analyzed to access its applicability. The model is referred as the discrete support model and abbreviated by DSM. For calibration, a 3D finite element (FE) model is created and validated by experiments. Formulas available in the literature are analyzed and new formulas for identifying parameters of the DSM are derived and validated over the range of typical track properties. These formulas are determined by fitting the results of the DSM to the 3D FE model using metaheuristic optimization. In addition, the range of applicability of the DSM is established. The new formulas are presented as a simple computational engineering tool, allowing one to calculate all the data needed for the DSM by adopting the geometrical and basic mechanical properties of the track. It is demonstrated that the currently available formulas have to be adapted to include inertial effects of the dynamically activated part of the foundation and that the contribution of the shear stiffness, being determined by ballast and foundation properties, is essential. Based on this conclusion, all similar models that neglect the shear resistance of the model and inertial properties of the foundation are unable to reproduce the deflection shape of the rail in a general way.

Polymer-based conductive membranes play an important role in the development of elastic deflection-based pressure sensors. In this paper, an analytical solution-based method is presented for the design and numerical calibration of polymer conductive membrane-based circular capacitive pressure sensors from non-touch mode of operation to touch mode of operation. The contact problem of a circular membrane in frictionless contact with a rigid flat plate under pressure is analytically solved, and its analytical solution is used for the design of touch mode circular capacitive pressure sensors for the first time. The analytical relationship with input pressure as independent variable and output capacitance as dependent variable is precisely derived and is used for the numerical calibrations of the analytical relationships with input capacitance as the independent variable and output pressure as the dependent variable in order to meet the capacitive pressure sensor mechanism of detecting pressure by measuring capacitance. For the first time, an example showing the design and numerical calibration of a given (given design parameters) polymer conductive membrane-based circular capacitive pressure sensor from non-touch mode of operation to touch mode of operation is provided. Then, the influence of changing several important design parameters on input capacitance–output pressure relationships is comprehensively investigated in order to clarify the desired input–output relationships when changing design parameters.

Numerical modeling is a powerful tool to determine the stress-strain relationships of structures. However, for a reliable application, physical and mathematical models must be calibrated and validated. This paper presents an overview of numerical calibration through the finite element method and plate-load tests in an embankment. Additionally, an analysis of the constitutive models used in soils is performed, and the elastic-plastic constitutive model of Mohr-Coulomb was selected since it is the best suited for this study. The results from three test areas within a refinery project that the Cuban government undertook in the province of Cienfuegos are used. The numerical model used in this study was calibrated by means of the error theory and the non-parametric hypothesis tests from Mann-Whitney U. From the practical point of view, this study gives two procedures to calibrate the numerical model with experimental results.

In this paper, an analytical solution-based method for the design and numerical calibration of polymer conductive membrane-based non-touch mode circular capacitive pressure sensors is presented. The accurate analytical relationship between the capacitance and applied pressure of the sensors is derived by using the analytical solution for the elastic behavior of the circular polymer conductive membranes under pressure. Based on numerical calculations using the accurate analytical relationship and the analytical solution, the analytical relationship between the pressure as output and the capacitance as input, which is necessary to achieve the capacitive pressure sensor mechanism of detecting pressure by measuring capacitance, is accurately established by least-squares data fitting. An example of how to arrive at the design and numerical calibration of a non-touch mode circular capacitive pressure sensor is first given. Then, the influence of changing design parameters such as membrane thickness and Young’s modulus of elasticity on input–output relationships is investigated, thus clarifying the direction of approaching the desired input–output relationships by changing design parameters.

Drawing on Harrod, Kalecki and Kaldor, this paper seeks to revive the view that ceteris paribus firms reduce investment if they have already built up high capacities relative to their assessment of the normal market potential. This reaction establishes a fundamental stabilizing mechanism for the economy. The paper adapts the idea to the growth context of a neo-Kaleckian baseline model, where its destabilizing Harrodian sentiment adjustments are specified in a canonical and microfounded way that introduces a natural nonlinearity into the global dynamics. Supposing local instability, the resulting two-dimensional system is shown to generate persistent self-sustaining cyclical behaviour. In addition, the model is numerically calibrated to period and amplitude of the US business cycle. On the whole, based on an old and almost forgotten conception, the paper advances a most elementary approach to business cycle modelling. [ABSTRACT FROM AUTHOR]

A methodology for a multi-process and multi-variable assessment of port operability/downtime in harbors, based on the historical characterization of the wave-induced response of moored ship systems at berths, in relation to both the historical outer- and in-port spectral wave climate, is presented in this paper. A joint numerical modeling and statistical approach is adopted with the objectives of exhaustive evaluation of port operability, uncertainty bounding and computational efficiency. First, the most accurate numerical configuration to predict the multivariate response of the moored ships is determined from an extensive catalog. This is done through a prototype-data-based performance assessment, where the complete time and spectral distributions of motion variables are used, instead of the classical time-averaged or spectrum-aggregated parameterizations. Secondly, an efficient assessment of port operability/downtime and safety is achieved based on a multivariate system response pattern-type approach related to representative wave climate conditions. This multi-process characterization allows to identify specific wave climate and mooring conditions triggering downtime or unsafe situations at berths. In addition, a tailor-made mooring plan can be suggested for each situation, also visualizing the operability and safety levels relative to each system response variable. Finally, a further characterization based on joint probability functions of motion amplitudes and periods over the berthing event's duration is proposed, showing the time variability of motion variables, and suggesting advancing beyond the classical monoparametric definitions. • Multi-process and multi-variable assessment of port operability/downtime in harbors. • Moored ship system response related to outer- and in-port spectral wave climate. • Multivariate response pattern-types visualizing the operability and safety levels. • Identifying wave and mooring problematic conditions, and tailor-made mooring plans. • Advanced approach beyond classical time-averaged or spectrum-aggregated parameters. [ABSTRACT FROM AUTHOR]

This paper presents the numerical short–open calibration (SOC) method in the full-wave finite-element method (FEM) algorithm for accurate de-embedding of equivalent circuit parameters of a variety of 3-D nonplanar periodic guided-wave and discontinuity structures. It holds its attractive features in high efficiency and good accuracy as demonstrated in the method of moments algorithm, and further allows itself to be capable of characterization of 3-D nonplanar structures. By setting the reference plane along each feeding line as the perfect electric and magnetic conductors, i.e., PEC and PMC, the entire error box involved in each feeding line and impressed source can be characterized by using these two calibration standards, namely, short- and open-ended circuits. Formulation of ABCD matrix of this error box is described under the introduction of an impressed voltage at each port. Then, ABCD matrix of the core circuit structure can be effectively de-embedded or extracted. Finally, a few numerical examples are given to demonstrate the efficiency and accuracy of our proposed full-wave 3-D FEM-SOC approach in numerical de-embedding of 3-D nonplaner structures. [ABSTRACT FROM PUBLISHER]

A combined method for determining the thermal conductivity of phase-change materials (PCMs) is proposed in this paper. A primary concern for this method is mitigating the effect of factors that exist in real experiments but are excluded in the measurement model. Thus, a measurement model was proposed to establish the mathematical relationship between the thermal conductivity and liquid fraction during the melting process. An experimental system was developed, and two different PCMs were used for the experiment. The thermal conductivity obtained via the experiments depicted an increasing trend during the entire melting process; these measurements were treated as the effective thermal conductivity of the PCM. The enhanced heat transfer rate prompted by natural convection was identified as the factor that affected the thermal conductivity measurement; a numerical calibration approach was presented to mitigate this influence. The numerical model considered all factors influencing the errors, and thermal conductivities were obtained via repeated iterations. Deviations between the calibrated thermal conductivity and reference data were less than 8%, meeting the practical requirements of engineering applications. • Proposed method for determining thermal conductivity of phase-change materials. • Relationship between thermal conductivity and liquid fraction is established. • Enhanced heat transfer rate affects thermal conductivity measurement. • Real thermal conductivities were obtained via repeated iterations. • Difference between calibrated thermal conductivity and reference values was <8%. [ABSTRACT FROM AUTHOR]

Die Umkehrbarkeit elastischer Wellen in linearen Systemen kann ausgenutzt werden, um zeitlich und lokal begrenzte Vibrationsereignisse auf Oberflächen zu erzeugen. Das damit verbundene Verfahren der Zeitumkehr findet bereits in anderen Bereichen der Medizintechnik, Werkstoffprüfung oder Lokalisierung von Fingerberührungen auf Oberflächen erfolgreichen Einsatz. Aufgrund der mit elastischen Wellen hervorgerufenen Oberflächenauslenkung bietet sich weiterführend die Möglichkeit, auf berührungssensitiven Bildschirmen dem Nutzer eine lokal begrenzte haptische Rückmeldung zu geben, um so beispielsweise auch für visuell beeinträchtigte Personen die Verwendbarkeit von Touch-Displays im täglichen Umfeld zu gewährleisten. Die Veröffentlichung demonstriert in diesem Kontext eine simulationsgestützte Studie zur Realisierung lokaler haptisch erfassbarer Vibrationsbereiche. The reversibility of an elastic wave can be used to refocus a signal on a local spot by time reversal (TR) techniques. Numerous application fields are connected to this technology, such as medical intervention, non-destructive testing or impact localization on touchscreen systems. However, since there is no haptic feedback, touchscreens require the users to visually control their interaction. This limits the usability in cases of individual physical constraints or environmental conditions. The contribution addresses a technique that uses elastic waves to realize a local vibro-tactile sensation on the screen, supported by simulation-based studies. [ABSTRACT FROM AUTHOR]

A study on local haptic feedback on panels by using a limited number of acoustic transducers is presented. Feasibility is discussed to enhance the time reversal (TR) technique [1] towards a virtual model-based calibration instead of an empirical. Reversibility of a structural elastic wave is used to refocus on arbitrary focal points. This enables producing a localized haptic interaction to a fingertip. The contribution includes the theoretical background, a simulation study and its empirical validation. [ABSTRACT FROM AUTHOR]

The hot water tanks are the typical thermal storage systems in Solar Domestic Hot Water (SDHW) plants. In this paper a new model for ESP-r has been developed, in order to simulate a tank in tank heat storage. The tank in tank system is made up of two tanks in which the smaller, storing potable hot water, is contained in a larger buffer filled with heating-circuit water. The developed model is an enhanced version of a component already available in ESP-r. Experimental results are used to identify some parameters and to perform the validation of the developed code. [ABSTRACT FROM AUTHOR]

For non-conventional or rapid forming processes important gradients of the plastic strain and strain rate can be reached, especially for severe loadings or complex deformation paths applied to the material. It is then required to improve the accuracy of the experimental data generally obtained from high speed mechanical tests as the Split Hopkinson Pressure Bar ones (SHPB). In the same time it is necessary to define quantitatively reliable rheological constitutive equations and adequate values of corresponding material coefficients. This paper proposes to use a Finite Element model for the simulation of the entire SHPB experiment based on a new calibration method of the raw measurements, together with some applications concerning the use of special specimen shapes in order to obtain large ranges variation of plastic strains and strain rate values. A description of an inverse analysis strategy, applied in order to identify the thermo-mechanical behavior laws of the materials and the computation of the corresponding rheological parameters, is also presented. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new numerical calibration procedure is proposed based on incremental dynamic analysis. [•] Five well known damage indices are calibrated on the basis of cracks opening width. [•] The procedure is generally applicable, robust and efficient. [ABSTRACT FROM AUTHOR]

• Mechanical model for dissipative reinforced concrete regions. • Representation of the cyclic performance of reinforced concrete structure. • Modelling calibration based on experimental tests. • Execution of nonlinear cyclic simulations. • Modelling calibration of materials constitutive laws. A mechanical model for the representation of the structural performance of the critical regions of reinforced concrete (RC) frame systems is provided and calibrated using the results of experimental tests on full-scale joints realized using different reinforcing steel grades. The proposed mechanical model describes the behaviour of the RC section along the plastic hinge length through a certain number of concrete and steel components, modelled as trusses located along the section's height. Kinematic constraints are introduced to simulate the rigid section performance, bond-slip springs are used to reproduce the lack of perfect bond. [ABSTRACT FROM AUTHOR]

The fauna of the Enspel (Westerwald) and the neighbouring Kärlich (Neuwied basin) fossil deposits correspond to the Upper Oligocene Mammal Paleogene (MP) reference level 28 and 28–30, respectively. Basaltic flows and a trachyte tuff terminating and predating the fossil deposit sedimentation allow to numerically calibrate the MP reference levels by radioisotope dating. Laser fusion 40Ar/39Ar step heating on volcanic feldspars yield a time interval of 24.9–24.5 Ma for reference level MP28 at Enspel and a maximum age of 25.5 Ma for the time interval MP28–MP30 at Kärlich. Interpolation between the time intervals determined for the Enspel reference level MP28 and the age of the global Oligocene/Miocene boundary of 24.0 ± 0.1 Ma taken from literature results in time intervals of 24.5–24.2 Ma and 24.2–23.9 Ma for the younger reference levels MP29 and MP30, respectively. These intervals of ≤ 0.4 m.y. for MP reference levels of the latest Oligocene are short relative to older Oligocene MP reference levels 21–27 between 34 and 25 Ma. Since subdivision into MP reference levels essentially is based on assemblages of mammal taxa and on evolutionary changes in tooth morphology of mammals short MP time intervals during the latest Oligocene indicate a rapid evolutionary change relative to the early Oligocene. [ABSTRACT FROM AUTHOR]

An efficient hybrid algorithm, known as the "domain decomposition finite-difference time-domain" (DD-FDTD) method combined with a numerical thru-line (TL) calibration technique, is proposed and developed for the accurate parameter extraction of microwave circuits and structures. By means of a TL technique, the developed FDTD algorithm not only greatly increases the accuracy of numerical simulations but it also saves computation time and memory space. Moreover, the hybrid algorithm can be used for the parameter extraction of arbitrary complex circuits and structures, such as substrate integrated circuits (SICs). The SICs that are studied in this work are based on substrate integrated waveguides, which are useful for the design of millimeter-wave planar circuits such as filters, resonators, and antennas. On the basis of the characteristic features of numerical calibration process, an idea of domain decomposition is introduced to simplify the procedure of programming and simulation and to increase the simulation's reliability. Simulation and measurement results have verified this hybrid algorithm. [ABSTRACT FROM AUTHOR]

Internal dose assessment can be derived from the measurement of retained activity in the whole body or in an organ at a given time. In radiation protection, this assessment, so-called in vivo measurement, is performed by an external measurement of the subject with germanium detectors (in most cases). Calibration of these detectors is ensured by anthropomorphic phantoms which, for technical reasons, can only provide rough representations of human. It is especially the case for the chest phantoms used in lung counting, subject of this paper. This leads to substantial corrections on calibration factors that are particularly crucial and delicate in low-energy in vivo measurements, resulting in important systematic errors. In order to improve calibration, former work based on numerical phantoms associated with Monte Carlo computing techniques has already proven its benefits. To go further, a Graphical User Interface called "OEDIPE", a French acronym for "tool for internal personalized dose assessment", has been developing at the IRSN internal dose assessment laboratory, simulating real measurements using person-specific computational phantoms in association with MCNP calculation code. The study presented here is dedicated to the implementation and validation of a real in vivo monitoring system (AREVA/COGEMA Marcoule, France) equipped with 4 high purity germanium (HPGe) detectors. After modeling the facility and measurement geometry using OEDIPE (design and positioning of the detectors…), validation with different configurations was carried out in two steps: first with point sources (different nuclides, different source-detector distances) and then with the Livermore calibration phantom (different overlay plates, lungs contaminated with 241Am and a mixture of actinides). The final goal is to approach a personalized numerical calibration of the facilities in order to improve dose assessment, as the use of physical phantoms for calibration induces large uncertainties. Such application could be an opening door on a better activity assessment in nuclear medicine, especially in personalized dosimetry in radioimmunotherapy. [ABSTRACT FROM AUTHOR]

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