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Wyszukujesz frazę "soft model" wg kryterium: Temat


Wyświetlanie 1-7 z 7
Tytuł:
Development of an Approximation Model of Selected Properties of Model Materials Used for Simulations of Bulk Metal Plastic Forming Processes Using Induction of Decision Trees
Autorzy:
Hawryluk, M.
Wilk-Kołodziejczyk, D.
Regulski, K.
Głowacki, M.
Powiązania:
https://bibliotekanauki.pl/articles/351927.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
regression tree induction
properties approximation
physical modelling
soft model materials
Opis:
The article discusses the development of an approximation model of selected plastic and mechanical properties obtained from compression tests of model materials used in physical modeling. The use of physical modeling with the use of soft model materials such as a synthetic wax branch with various modifiers is a popular tool used as an alternative or verification of numerical modeling of bulk metal forming processes. In order to develop an algorithm to facilitate the choice of material model to simulate the behavior of real-metallic materials used in industrial production processes the induction of decision trees was used. First of all, the Statistica program was used for data mining, which made it possible to determine / find the relationship between the percentage of particular constituents of the model material (base material and modifiers) and yield strength, critical and maximum strain, and provide the opportunity to indicate the most important variables determining the shape of the stress - strain curve. Next, using the induction of decision trees, an approximation model was developed, which allowed to create an algorithm facilitating the selection of individual modifying components. The last stage of the research was verification of the correctness of the developed algorithm. The obtained research results indicate the possibility of using decision tree induction to approximate selected properties of modeling materials simulating the behavior of real materials, thus eliminating the need for costly and time-consuming experiments carried out on metallic material.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 3; 1073-1085
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stress-Induced Anisotropy and Stress Dependence of Saturation Magnetostriction in the Jiles-Atherton-Sablik Model of the Magnetoelastic Villari Effect
Autorzy:
Szewczyk, R.
Powiązania:
https://bibliotekanauki.pl/articles/355063.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnetic hysteresis model
soft ferrite
magnetoelastic anisotropy
Opis:
The paper presents the results of the magnetoelastic Villari effect modelling in high-permeability Mn0.51Zn0.44Fe2.05O4 ferrite. Modelling was performed on the basis of measurements of magnetoelastic characteristics of frame-shaped samples. For the modelling, the corrected Jiles-Atherton-Sablik model was used. On the base of modelling results, the stress dependence of parameter k and stress-induced anisotropy were estimated. As a result the changes of saturation magnetostriction of Mn0.51Zn0.44Fe2.05O4 ferrite subjected to stresses were calculated. Such changes were previously observed experimentally. However, the phenomenon of stress-induced sign change of saturation magnetostriction was never previously explained quantitatively.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 2A; 607-612
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel method of handling tolerances for analog circuit fault diagnosis based on normal quotient distribution
Autorzy:
Ao, Y.
Shi, Y.
Zhang, W.
Li, X.
Powiązania:
https://bibliotekanauki.pl/articles/221119.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
soft-fault diagnosis
analog circuit
Normal Quotient Distribution
Slope Fault Model
Opis:
While the Slope Fault Model method can solve the soft-fault diagnosis problem in linear analog circuit effectively, the challenging tolerance problem is still unsolved. In this paper, a proposed Normal Quotient Distribution approach was combined with the Slope Fault Model to handle the tolerances problem in soft-fault diagnosis for analog circuit. Firstly, the principle of the Slope Fault Model is presented, and the huge computation of traditional Slope Fault Characteristic set was reduced greatly by the elimination of superfluous features. Several typical tolerance handling methods on the ground of the Slope Fault Model were compared. Then, the approximating distribution function of the Slope Fault Characteristic was deduced and sufficient conditions were given to improve the approximation accuracy. The monotonous and continuous mapping between Normal Quotient Distribution and standard normal distribution was proved. Thus the estimation formulas about the ranges of the Slope Fault Characteristic were deduced. After that, a new test-nodes selection algorithm based on the reduced Slope Fault Characteristic ranges set was designed. Finally, two numerical experiments were done to illustrate the proposed approach and demonstrate its effectiveness.
Źródło:
Metrology and Measurement Systems; 2012, 19, 4; 817-830
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical identification of Preisach distribution function including temperature effects
Autorzy:
Chelghoum, Leila
Powiązania:
https://bibliotekanauki.pl/articles/2086685.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnetic hysteresis
Preisach distribution function
Preisach model
soft ferromagnetic materials
temperature effect
Opis:
Magnetic hysteresis occurs in most electrical engineering devices once soft ferromagnetic materials are exposed to relatively high temperatures. According to several scientific studies, magnetic properties are strongly influenced by temperature. The development of models that can accurately describe the thermal effect on ferromagnetic materials is still an issue that inspires researchers. In this paper, the effect of temperature on magnetic hysteresis for ferromagnetic materials is investigated using a self-developed numerical method based on the Preisach distribution function identification. It employs a parameter depending on both temperature and the Curie temperature. This approach is of the macroscopic phenomenological type, where the variation of the magnetization (in direct connection with the Preisach triangle) is related to the observed macroscopic hysteretic behavior. The isotropic character of the material medium is predominant. The technique relies on a few experimental data extracted from the first magnetization curve provided by metallurgists. The ultimate goal is to provide a simple and robust magnetic behavior modeling tool for designers of electrical devices. Temperature is introduced at the stage of identifying the distribution function of the Preisach model. This method is validated by the agreement between the experimental data and the simulation results. The developed method is very accurate and efficient in modeling the hysteresis of ferromagnetic materials in engineering particularly for systems with ferromagnetic components and electromagnetic-thermal coupling.
Źródło:
Archives of Electrical Engineering; 2022, 71, 2; 297--309
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of test embankment on soft ground using multi-laminate type model with destructuration
Analiza numeryczna nasypu drogowego posadowionego na gruncie słabonośnym z zastosowaniem modelu wielopłaszczyznowego z destrukturyzacją
Autorzy:
Cudny, M.
Powiązania:
https://bibliotekanauki.pl/articles/230505.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
geomechanika
modelowanie konstytutywne
nasyp drogowy
grunt słaby

model wielopłaszczyznowy
anizotropia
geomechanics
constitutive modelling
road embankment
soft soil
clay
multi-laminate type model
anisotropy
Opis:
A multi-laminate constitutive model for soft soils incorporating structural anisotropy is presented. Stress induced anisotropy of strength, which is present in multi-laminate type constitutive models, is augmented by directionally distributed overconsolidation. The model is presented in the elastic-plastic version in order to simulate strength anisotropy of soft clayey soils and destructuration effects. Performance of the model is shown for some element tests and for the numerical simulation of a trial road embankment constructed on soft clays at Haarajoki, Finland. The numerical calculations are completed with the commercial finite element code capable to perform coupled static/consolidation analysis of soils. Problems related to the initiation of in situ stress state, conditions of preconsolidation, as well as difficulties linked to estimation of the model parameters are discussed. Despite simple assumptions concerning field conditions and non-viscous formulation of the constitutive model, the obtained final results are of a sufficient accuracy for geotechnical practice.
W artykule przedstawiono model wielopłaszczyznowy (multi-Iaminate) uwzgledniający anizotropię struktury słabonośnych gruntów drobnoziarnistych. Anizotropia indukowana naprężeniem, którą otrzymuje się przy zastosowaniu modeli wielopłaszczyznowych, jest dodatkowo wzmocniona poprzez wprowadzene prekonsolidacji zależnej od orientacji przestrzennej. Model przedstawiono w wersji sprężysto-plastycznej, w której możliwa jest symulacja anizotropii wytrzymałości słabonośnych gruntów drobnoziarnistych oraz zjawiska destrukturyzacji. Działanie modelu pokazano w symulacjach numerycznych wybranych badań elementarnych oraz przy zastosowaniu w modelowaniu numerycznym odkształcenia słabonośnego podłoża gruntowego pod próbnym nasypem drogowym w Haarajoki, Finlandia. Symulację numeryczną przeprowadzono przy użyciu komercyjnego programu metody elementów skończonych pozwalającego na analizę sprzężonych zagadnień brzegowych statyki i konsolidacji. Omówiono zagadnienia związane z przyjęciem warunków początkowych stanu naprężenia in situ oraz warunków prekonsolidacji, jak również przedstawiono problemy związane z przyjęciem parametrów modelu. Pomimo przyjęcia prostych zasad dotyczących warunków początkowych oraz przy pominięciu efektów lepkości w modelu konstytutywnym, otrzymane wyniki pozwoliły na osiągnięcie wystarczającej w praktyce geotechnicznej dokładności w stosunku do wartości pomierzonych.
Źródło:
Archives of Civil Engineering; 2011, 57, 1; 27-44
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Short-term wind power combined prediction based on EWT-SMMKL methods
Autorzy:
Li, Jun
Ma, Liancai
Powiązania:
https://bibliotekanauki.pl/articles/1955182.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
combined model
empirical wavelet transform
prediction
soft margin multiple kernel learning
wind power
model łączony
empiryczna transformacja falkowa
przewidywanie
miękki margines uczenia wielokrotnego jądra
energia wiatrowa
Opis:
Since wind power generation has strong randomness and is difficult to predict, a class of combined prediction methods based on empirical wavelet transform (EWT) and soft margin multiple kernel learning (SMMKL) is proposed in this paper. As a new approach to build adaptive wavelets, the main idea is to extract the different modes of signals by designing an appropriate wavelet filter bank. The SMMKL method effectively avoids the disadvantage of the hard margin MKL method of selecting only a few base kernels and discarding other useful basis kernels when solving for the objective function. Firstly, the EWT method is used to decompose the time series data. Secondly, different SMMKL forecasting models are constructed for the sub-sequences formed by each mode component signal. The training processes of the forecasting model are respectively implemented by two different methods, i.e., the hinge loss soft margin MKL and the square hinge loss soft margin MKL. Simultaneously, the ultimate forecasting results can be obtained by the superposition of the corresponding forecasting model. In order to verify the effectiveness of the proposed method, it was applied to an actual wind speed data set from National Renewable Energy Laboratory (NREL) for short-term wind power single-step or multi-step time series indirectly forecasting. Compared with a radial basic function (RBF) kernel- based support vector machine (SVM), using SimpleMKL under the same condition, the experimental results show that the proposed EWT-SMMKL methods based on two different algorithms have higher forecasting accuracy, and the combined models show effectiveness.
Źródło:
Archives of Electrical Engineering; 2021, 70, 4; 801-817
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of the settlement prediction in soft soil by Richards Model: based on a linear least squares-iteration method
Autorzy:
Nadeem, Muhammad
Akbar, Muhammad
Huali, Pan
Xiaoqing, Li
Guoqiang, Ou
Amin, Azka
Powiązania:
https://bibliotekanauki.pl/articles/1852538.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metoda iteracji liniowej
metoda najmniejszych kwadratów
prognoza
grunt słaby
podłoże gruntowe
błąd porównawczy
osiadanie gruntu
model obliczeniowy
linear iterative method
least square method
prediction
soft soil
comparative error
settlement
calculation model
Opis:
Prediction of soft soil sub-grades settlement has been a big challenge for geotechnical engineers that are responsible for the design of roadbed embankment. The characteristics of low strength, poor permeability, high water contents, and high compressibility are dominant in soft soils, which result in a huge settlement in the case of long-term loading. The settlement prediction in soft soil subgrades of Jiehui Expressway A1, Guangdong, China, is the focus of this study. For this purpose, the necessary data of settlement is collected throughout the project execution. The numerical analysis is conducted by using the Richards model based on Linear Least Squares Iteration (LLS-I) method to calculate and predict the expected settlement. The traditional settlement prediction methods, including the hyperbolic method, exponential curve method, and pearl curve method, are applied on field settlement data of soft soil subgrades of Jiehui Expressway A1. The results show that the Richards model based on Linear Least Squares Iteration (LLS-I) method has high precision, and it has proven to be a better option for settlement prediction of soft soil sub-grades. The model analysis indicates that the mean absolute percentage error (MAPE) can be minimized as compared to other soft soil sub-grades settlement prediction methods. Hence, Richards's model-based LLS-I method has a capability for simulation and settlement prediction of soft soil subgrades.
Źródło:
Archives of Civil Engineering; 2021, 67, 2; 491-506
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

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