Zhanwei Liu, Huimin Xie, Fulong Dai

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.3, pp. 95-96, 2011, DOI:10.3970/icces.2011.018.095

Abstract The mechanical behaviors of microstructures and micro devices have drawn the attention from researchers on materials and mechanics recently. To understand the rule of these behaviors, the deformation measurement techniques with micro/nanometer sensitivity and spatial resolution are required. In this report, a geometric phase analysis technique, SEM scanning moirAC method, digital phase moirAC method based on gratings and a micro-marker identification method are introduced to meet the deformation evaluation requirement of MEMS. The geometric phase analysis technique is performed on the basis of regular gratings, instead of natural atom lattice. The regular gratings with a pitch of range from micrometer… More >

A.Y.Chen, J. Lu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 45-46, 2011, DOI:10.3970/icces.2011.020.045

Abstract The structural reliability of many brittle materials such as nanomaterials relies on the occurrence of intergranular, as opposed to transgranular, fracture in order to induce toughening by crack bridging. The current work examines the role of interface strength and grain size distribution in promoting intergranular fracture in order to maintain high toughening. A layered nanostructural 304SS sheet characterized by periodic distribution of nanocrystalline layers and micron-grained layers with graded grain size evolution has exhibited exceptional properties. The in situ SEM observations illustrate that an intergranular path and the consequent interface bridging process can be partitioned into five distinct regimes, namely:… More >

Surya R. Kalidindi, Stephen R. Niezgoda, Ayman A. Salem

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.3, pp. 79-80, 2011, DOI:10.3970/icces.2011.016.079

Abstract Microstructure Informatics is a critical building block of ICME infrastructure. Accelerated design and development of new advanced materials with improved performance characteristics and their successful insertion in engineering practice are largely hindered by the lack of a rigorous mathematical framework for the robust generation of microstructure informatics relevant to the specific application. In this paper, we describe a set of novel and efficient computational protocols that are capable of accelerating significantly the process of building the needed microstructure informatics for a targeted application. These novel protocols have several advantages over the current practice in the field: (i) they allow archival,… More >

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 >

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 >

Dmitry S. Bulgarevich^1,*, Susumu Tsukamoto¹, Tadashi Kasuya², Masahiko Demura¹, Makoto Watanabe^1,3

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 >

K. G. Wang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.5, No.3, pp. 179-186, 2008, DOI:10.3970/icces.2008.005.179

Abstract Microstructural modeling is very important because it can provide a critical link between properties, mesoscopic length scale, and atomistic scale (multiscale modeling). There exist a couple of models and simulations to study microstructural evolution. It will be important and useful to discover unified model equations hidden in microstructure evolution. In this paper, I will derive the unified model equations for microstructure evolution. The governing equations in Lifshitz-Slyozov-Wagner theory and diffusion screening theory that modeled microstructural evolution are derived with some approximations from the unified model equations. The governing equations in multiparticle diffusion simulation and phase-field simulation in microstructure evolution are… More >

E. M. Ciannamea^1,*, L. A. Castillo^2,3, R. A. Ruseckaite¹, S. E. Barbosa^2,3

Journal of Renewable Materials, Vol.7, No.1, pp. 21-30, 2019, DOI:10.32604/jrm.2019.00043

Abstract Blends of gelatin (Ge) plasticized with varying amounts of glycerol (Gly), buffer solution pH 10 and epoxidized soybean oil (ESO) to enhance hydrophobicity were prepared by mixing and injection-molding. Blends were characterized by rheological tests and microscopy to select optimal conditions for scaling up their processing. The effect of each component on rheological response was analyzed using parallel plate geometry. Coating of gelatin specimens with PDMS during rheological tests led to reliable and reproducible results since water evaporation was prevented. A gradual increment in ESO concentration led to blends with increased degree of phase separation, as evidenced by optical and… More >

Hiroshi Kadowaki¹, Wing Kam Liu²

CMES-Computer Modeling in Engineering & Sciences, Vol.7, No.3, pp. 269-282, 2005, DOI:10.3970/cmes.2005.007.269

Abstract A method to derive governing equations and elastic-plastic constitutive relations for the micropolar continuum model is proposed. Averaging procedures are operated over a surrounding sub-domain for each material point to bridge a discrete microstructure to a macro continuum model. Material parameters are determined by these procedures. The size of the sub-domain represents the material intrinsic length scale, and it is passed into the macroscopic governing equation so that the numerical solution can be regularized for analyses of failure phenomena. An application to a simple granular material model is presented. More >

P. Raghavan¹, S. Ghosh²

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.2, pp. 151-170, 2004, DOI:10.3970/cmes.2004.005.151

Abstract This paper presents an adaptive multi-level computational model that combines a conventional displacement based finite element model with a microstructural Voronoi cell finite element model for multi-scale analysis of composite structures with non-uniform microstructural heterogeneities as obtained from optical or scanning electron micrographs. Three levels of hierarchy, with different resolutions, are introduced in this model to overcome shortcomings posed by modeling and discretization errors. Among the three levels are: (a) level-0 of pure macroscopic analysis; (b) level-1 of macro-micro coupled modeling, used for signaling the switch over from macroscopic analyses to pure microscopic analyses; and (c) level-2 regions of pure… More >