Journals / ICCES / Vol.22, No.2
Table of Content

  • ABSTRACT

    Numerical Analysis on Hydrogen Diffusion Behaviour in Multi Materials Related to Weld Joint

    A.Toshimitsu Yokobori Jr1,*, Go. Ozeki1, Toshihito OHMI1,2, Tadashi Kasuya3, Nobuyuki Ishikawa4, Manabu Enoki3, Satoshi Minamoto5
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 119-119, 2019, DOI:10.32604/icces.2019.05177
    Abstract Authors have been founded that hydrogen diffusion and concentration behavior for notched specimens of multi-materials with space distribution of various material properties were dominated not only by the space gradient of hydrostatic stress caused by the notch tip, ∇σp but also by that of diffusion coefficient, ∇D(T, HV, εp) caused by space distributions of temperature, hardness and plastic strain due to multi-materials. In this research, on the basis of our proposed coupled analysis of heat transfer induced thermal stress driven hydrogen diffusion, the effect of ∇D(T, HV, εp) ) on hydrogen concentration behavior was clarified by solving the problem of… More >

  • ABSTRACT

    Empirical Formulae to Predict Hardness, Hydrogen Diffusion Coefficient and Tensile Properties of Steel HAZ

    Tadashi Kasuya1,*, A. Toshimitsu Yokobori Jr2, Nobuyuki Ishikawa3, Manabu Enoki1, Satoshi Minamoto4
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 120-120, 2019, DOI:10.32604/icces.2019.05227
    Abstract Weld cold cracking is categorized as hydrogen cracking. To assess cold cracking susceptibility of steel HAZ (heat affected zone), it is necessary to estimate local hydrogen content and residual stress at a weld root that are in general numerically calculated by FEM and/or FDM. To conduct numerical calculations, physical and mechanical properties such as diffusion coefficient of hydrogen in steel are necessary. In this work, we have developed empirical formulae to calculate HAZ hardness, hydrogen diffusion coefficient and tensile properties. The present empirical formula of HAZ hardness is expressed using chemical compositions of a welded steel and weld thermal history.… More >

  • ABSTRACT

    Creep Model Selection for Grade 91 Steel Using Data Scientific Method

    Hitoshi Izuno1, Masahiko Demura1,*, Masaaki Tabuchi2, Yohichi Mototake3, Masato Okada1,3
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 121-121, 2019, DOI:10.32604/icces.2019.05270
    Abstract An accurate creep deformation model is needed for detailed description of creep behavior of high temperature structural materials, e.g., Grade 91 steels used in boiler tubes of thermal power plants. Two types of creep constitutive equations are known, as follows: the one, e.g., modified theta method, assumes the existence of a steady state; and the other, e.g., theta method, does not. So far, both types have been selected on a case by case basis and there is no consensus on whether or not the steady state should be assumed even if limited in the Grade 91 steels. In this study,… More >

  • ABSTRACT

    Image Processing/Machine-Learning for Auto-Labeling of Steel Images on Present Microstructures

    Dmitry S. Bulgarevich1,*, Susumu Tsukamoto1, Tadashi Kasuya2, Masahiko Demura1, Makoto Watanabe1,3
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 122-122, 2019, DOI:10.32604/icces.2019.05271
    Abstract The microstructure of steel greatly determines its mechanical properties/performance and holds information on chemical composition and processing history. Therefore, quantitative analysis of optical or SEM images on formed microstructure phases is one of the primary interests for metallurgy. So far, such analyses in laboratories are done manually by experts and are very time consuming. However, with modern microscopy techniques of automated image acquisitions over the large imaging areas and even by using of sample slicing for three-dimensional imaging, the amount of image data could be overwhelming for manual examinations. In this respect, there is a possibility that machine learning (ML)… More >

  • ABSTRACT

    Machine Learning Prediction of Creep Rupture Time for Steels

    Masahiko Demura1,*, Junya Sakurai1,2, Masayoshi Yamazaki1, Junya Inoue1,2
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 123-123, 2019, DOI:10.32604/icces.2019.05303
    Abstract Creep is a complicated and time-dependent phenomenon, which is affected by the initial state and the degradation of microstructures. It is thus considered that the information about the microstructure is essential to predict the creep rupture time. On the other hand, there is a strong, practical need for the prediction without the investigation of microstructures nor the disclosure of the detailed process that should control the initial microstructures. In this study, we examined how modern machine learning technique can help to predict the creep rupture time in heat-resistant ferrite-type steels without the direct information about the microstructures and the process… More >

  • ABSTRACT

    Evaluation of Fatigue Performance in Welded Structures by Microstructure-Based Simulation

    Takayuki Shiraiwa*, Fabien Briffod, Manabu Enoki
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 124-124, 2019, DOI:10.32604/icces.2019.05311
    Abstract The purpose of this study is to evaluate fatigue performances of welded structures using numerical simulations. The fatigue life of welded joint is complicatedly affected by various factors such as geometries, defects, residual stress and microstructure. Conventional fatigue life assessments are generally based on fracture mechanics and predict the fatigue life for long crack propagation. In order to predict the total fatigue life more accurately, it is necessary to consider the lifetime for crack initiation and microstructually short crack (MSC) growth. In this study, a numerical framework to predict the fatigue life including crack initiation, MSC growth and long crack… More >

  • ABSTRACT

    In Situ Microscopic Observation and Crystal Plasticity Simulation of Fatigue Crack Formation in Ti-6Al-4V Alloy

    Fabien Briffod*, Alexandre Bleuset, Takayuki Shiraiwa, Manabu Enoki
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 125-125, 2019, DOI:10.32604/icces.2019.05319
    Abstract The fatigue behavior of metallic materials is a multi-scale problem (from a time and length-scale perspective) intimately influenced by microstructural features that determine the early stages of crack propagation. Prediction of fatigue life is traditionally based on the evaluation of macroscopic mechanical fields at the structure level and on the application of empirical rules. However, these structure-oriented methods are material-specific and do not consider the material variability at lower scales. Hence, reliable prediction of fatigue performances and its variability requires on one side the characterization and quantification of early damage mechanisms and on the other side the incorporation of local… More >

  • ABSTRACT

    Role of Microstructure on Small Fatigue Crack Initiation and Propagation behavior of Rolled and Forged Ti-6Al-4V Alloy

    Hideaki NISHIKAWA*, Yoshiyuki FURUYA
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 126-126, 2019, DOI:10.32604/icces.2019.05354
    Abstract Fatigue life is determined by microscopic fatigue crack initiation and growth. Since fatigue crack is generally initiated on the slip plane of microstructure and propagated by slip deformation of the crack tip, fatigue life should depends on microstructure. To computationally simulate the effect of microstructure on fatigue property, it is necessary to understand microstructural small fatigue crack initiation and growth behavior. Although Ti-6Al-4V alloy has superior fatigue strength, fatigue strength of forged pancake, used for such as airplane engine, is normally lower than that of rolled alloy. It is possibly comes from microstructural difference, such as micro-texture. However, it is… More >

  • ABSTRACT

    Data Assimilation for Grain Growth Prediction via Multi-Phase-Field Models

    Hiromichi Nagao1,2,*, Shin-ichi Ito1,2, Tadashi Kasuya3, Junya Inoue4,3
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 127-127, 2019, DOI:10.32604/icces.2019.05384
    Abstract Data assimilation (DA) is a computational technique to integrate numerical simulation models and observational/experimental data based on Bayesian statistics. DA is accepted as an essential methodology for the modern weather forecasting, and is applied to various fields of science including structural materials science. We propose a DA methodology to evaluate unobservable parameters involved in multi-phase-field models with the aim of accurately predicting the observed grain growth, such as in metals and alloys. This approach integrates models and a set of observational image data of grain structures. Since the set of image data is not a time series, directly applying conventional… More >

  • ABSTRACT

    Descriptor Extraction on Inherent Creep Strength of Carbon Steels by Exhaustive Search

    Junya Sakurai1, Junya Inoue2,3,4, Masahiko Demura4,*, Yoichi Mototake5, Masato Okada4,5, Masayoshi Yamazaki4
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 128-128, 2019, DOI:10.32604/icces.2019.05408
    Abstract According to the inherent creep strength concept proposed by Kimura et al., microstructural strengthening effect is expiring after a long-term creep deformation at high temperature. In the region, the solid solution hardening effect becomes dominant so that the rupture time is expected to be a simple function of chemical composition and test conditions. In fact, they found that there was a linear relationship between logarithm rupture time and the amount of Mo for the carbon steel JIS STB410. They also found the positive correlations of Cr and Mn to the logarithmic rupture time. However, it is difficult to specify the… More >

  • ABSTRACT

    Universal Framework of Bayesian Creep Model Selection for Steel

    Yoh-ichi Mototake1, Hitoshi Izuno2, Kenji Nagata3,4, Masahiko Demura2 , Masato Okada1,2,*
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 129-130, 2019, DOI:10.32604/icces.2019.05389
    Abstract The creep deformation process is constructed by complex interactions of multiple factors, and the measurement of creep deformation requires enormous economic costs and a long experimental time, so there is a small amount of measurement data. In such a situation, multiple models are often proposed to explain the same experimental data. The coexistence of multiple models based on different physical assumptions makes it difficult to understand the creep deformation process.
    The purpose of this study is to construct a framework to compare and evaluate coexistence models based on measurement data using the Bayesian model selection framework. Basically, in the… More >

  • ABSTRACT

    Development of Materials Integration System for Structural Materials

    M. Watanabe*, S. Minamoto, T. Kadohira, K. Ito, M. Demura
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 131-132, 2019, DOI:10.32604/icces.2019.05416
    Abstract This article has no abstract. More >

  • ABSTRACT

    Experimental Investigation and Thermodynamic Assessment of the Fe-Base Alloy System

    Ikuo Ohnuma, Machiko Ode
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 133-133, 2019, DOI:10.32604/icces.2019.05431
    Abstract Experimental investigation of phase equilibria in the Fe-Mn, Fe-Si, Fe-Al and Fe-Mn-Si-C systems was carried out. In the Fe-Mn system, α/γ equilibrium at temperatures below 600°C was revised by equilibration of severely deformed powder samples in which the α/γ equilibrated microstructures at low temperatures could be realized. In the Fe-Si and Fe-Al systems, the miscibility gap between A2, B2 and D03 phases as well as the A2/B2/D03 transition boundaries were determined precisely. Phase equilibria in the Al-rich region of the Fe-Al system were determined in detail. The α/γ equilibria in the Fe-Mn-C, Fe-Mn-C and Fe-Mn-Si-C systems were determined by FE-EPMA,… More >

  • ABSTRACT

    Connection and Execution of Prediction Modules Using the MI Workflow System

    Kaita Ito*, Satoshi Minamoto, Takuya Kadohira, Makoto Watanabe, Masahiko Demura
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 134-134, 2019, DOI:10.32604/icces.2019.05440
    Abstract In the Materials Integration (MI) system, workflow designers and players are implemented as ones of the core subsystems. When the user wants to predict a certain material parameter by using the MI system, the user selects a prediction module in the workflow designer that can output the objective parameter. If the all required input parameters of the prediction module are not given directly, further modules can be connected.
    Each input and output parameters of the prediction module on the MI system is directly associated with one term of material science and engineering. It is not defined as a specific… More >

  • ABSTRACT

    Establishment of Structure-Property Linkages Using a Bayesian Model Selection Method: Application to A Dual-Phase Metallic Composite System

    Hoheok Kim1, Tatsuki Yamamoto2, Yushi Sato1, Junya Inoue1,3,4,*
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 135-135, 2019, DOI:10.32604/icces.2019.05453
    Abstract The viability of establishing low-cost surrogate structure-property (S-P) linkages which applies a Bayesian model selection method to the Materials Knowledge System (MKS) homogenization framework is studied. The MKS framework employs the n-point correlation function, principal component analysis, and regression techniques for mapping between the structural factors and the property of a material. However, the framework chooses the factors not by their influence on the property but by their amount of inherent microstructural information. This also makes it difficult to find out which microstructural morphology affects the property. In the present work, we introduced a Bayesian model selection method to choose… More >

  • ABSTRACT

    Prediction Models Generation by Machine Learning for Structural Materials Performance by Utilizing the Mi System

    Satoshi Minamoto*, Takuya Kadohira, Kaita Ito, Makoto Watanabe, Masahiko Demura
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 136-136, 2019, DOI:10.32604/icces.2019.05447
    Abstract The Materials Integration (MI) System is a domestically developed system in the “Cross-ministerial Strategic Innovation Promotion Program” to analyze structural materials performance. The performance on structural materials having complicated inputs/outputs would be solved with the combination of different scientific programs or data from experiment. One of the merits of constructing a combined model (here we call workflow) is that calculations are performed and the data would be stored in the system automatically.
    Furthermore, we developed a web application (“MIREA”: MI REgression Analyzer) that enables us to build high versatile prediction models based on machine learning techniques by using the… More >

  • ABSTRACT

    Virtual Research Environment Integrating Heterogeneous Data Resources for Materials Science and Engineering

    Toshihiro Ashino1,*, Nobutaka Nishikawa2
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 137-137, 2019, DOI:10.32604/icces.2019.05454
    Abstract Materials performance analysis process requires integration of many heterogeneous data and information resources, e.g. experimental data, empirical models and computational simulation. Virtual Research Environment (VRE) for materials science and engineering should support each data handling processes, data retrieval, conversion, statistical analysis, symbolic manipulation and visualization within single interactive and scripting environment.
    Furthermore, in order to integrate heterogeneous data, it requires a common dictionary which describe semantic relationships among these data resources. It is required to identify corresponding data items from different data resources. It can be a flat structured table, but an ontology which describes semantic relationships among concepts,… More >

  • ABSTRACT

    Prediction Model for Weld Hydrogen Cracking in High Strength Steel Weld

    Nobuyuki Ishikawa1,*, Yuya Sato1, A. Toshimitsu Yokobori Jr.2, Tadashi Kasuya3, Satoshi Minamoto4, Takehiro Endo3, Manabu Enoki3
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 138-138, 2019, DOI:10.32604/icces.2019.05518
    Abstract Prediction model for weld hydrogen cracking (so called cold cracking) in high strength steel weld was developed by a coupled thermo-elastic-plastic and hydrogen diffusion analysis in the y-grooved weld joint. Critical conditions of cracking was given as the function of principal stress and accumulated hydrogen concentration in the root region where the cracking occurs. In order to clarify the critical conditions of cold cracking, y-grooved cold cracking tests were first conducted using the steel plate with tensile strength level of 780MPa. Plate thickness of the plates were 25 mm and 50 mm. Hydrogen concentration in the weld metal was changed… More >

  • ABSTRACT

    Numerical Model for Predicting Charpy Impact Toughness of Weld Heat-Affected Zone of Steels

    M. Inomoto1,*, S. Aihara2, T. Kasuya2, T. Kawabata2, Y. Okazaki1
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 139-139, 2019, DOI:10.32604/icces.2019.05781
    Abstract Prediction of toughness of weld heat-affected zone (HAZ) of steels is a difficult task because it is controlled by many parameters including grain-size, brittle microphase, hardness, etc. No reliable model has been established, yet. In the present study, a numerical model for predicting Charpy impact toughness of weld HAZ of steels has been developed. The model comprises two parts: phase transformation and toughness prediction. In the former part, phase fraction, size distribution of martensite-austenite brittle microphase, hardness, size of grain boundary ferrite and bainitic ferrite plate, etc. are calculated and these parameters are used in the latter part, in which… More >

  • ABSTRACT

    Converting Vacuum Residue Into Light Fuels By Self-Fluidized Pump-Free Ebullated-Bed Hydrocracking

    Tao Yang, Zhaohui Meng, Hailong Ge, Xiangchen Fang*
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 140-140, 2019, DOI:10.32604/icces.2019.04917
    Abstract Vacuum residue (VR) is the heaviest distillation cuts of crude oil. Being very intractable, VR contains high amount of sulfur, metal and asphaltene. Conventional VR conversion technologies, including delayed coker and residue fluidized catalytic cracking, cannot remove those impurities efficiently, or have to employ strict pretreatments for feed stock to meet the equipment and catalyst requirements. Hydroprocessing and hydrocracking process can convert VR into lighter oils, and remove sulfur and metal content at high efficiency; the refining nature of hydrogenation reactions could also improve the molecular structures of product cuts, increasing the commercial values. According to the fluidization state of… More >

Share Link

WeChat scan