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Mode Method (mode + method)
Selected AbstractsFailure of heterogeneous materials: 3D meso-scale FE models with embedded discontinuitiesINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 13 2010N. Benkemoun Abstract We present a meso-scale model for failure of heterogeneous quasi-brittle materials. The model problem of heterogeneous materials that is addressed in detail is based on two-phase 3D representation of reinforced heterogeneous materials, such as concrete, where the inclusions are melt within the matrix. The quasi-brittle failure mechanisms are described by the spatial truss representation, which is defined by the chosen Voronoi mesh. In order to explicitly incorporate heterogeneities with no need to change this mesh, some bar elements are cut by the phase-interface and must be split into two parts. Any such element is enhanced using both weak and strong discontinuities, based upon the Incompatible Mode Method. Furthermore, a dedicated operator split solution procedure is proposed to keep local any additional computation on elements with embedded discontinuities. The results for several numerical simulations are presented to illustrate the capabilities of the proposed model to provide an excellent representation of failure mechanisms for any different macroscopic loading path. Copyright © 2010 John Wiley & Sons, Ltd. [source] Age-associated changes in the amount of subcutaneous tissue in the face evaluated in the ultrasonic B modeINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 2 2005M. Satoh In this study, age-associated changes in facial skin, cosmetologically critical factors, were studied in terms of local subcutaneous fat tissue. The subjects were 98 Japanese females evenly chosen from their teens to 70s. On each subject, the thickness of subcutaneous tissue was determined by the ultrasonic B mode method on four facial sites, forehead, orbit, cheek, and mandible. Age-association of the tissue thickness was facial site-dependent. In the orbit, the subcutaneous tissue became thicker with age, whereas it showed a tendency of thinning in the forehead. No clear age-association was observed in the cheek or the mandible. To analyze the age-association further, the data were stratified into ,lean group' and ,obese group' based on their BMI, and subjected to multiple regression analysis. The age-association in the orbit was much more distinctive in the lean group than in the obese group. [source] Validation of LAB Color Mode as a Nondestructive Method to Differentiate Black Ballpoint Pen Inks,JOURNAL OF FORENSIC SCIENCES, Issue 4 2007Derek L. Hammond B.A. Abstract:, Nondestructive digital processing methods such as lab color mode (available in Adobe® Photoshop®) are emerging as alternative methods for forensic document examiners to use when attempting to differentiate writing instrument inks. Although these techniques appear to be viable, little data currently exists regarding the known or potential error rates associated with these techniques. Without adequate data, the validity and reliability of these techniques, including lab color, can not be established. In an attempt to begin to address these issues, 44 black ballpoint ink pens were obtained and used to create 990 pen-pair samples for analysis using established lab color mode techniques. No erroneous findings of "different" were reported following the examination of the known pen-pair combinations in which the same pen was used to create the samples (n = 44). Of the remaining 946 samples, 737 pen-pair samples were differentiated using the lab color mode method, while 209 samples were unable to be differentiated and were recorded as either being "similar" (n = 153) or "unsure" (n = 56). Comparison of the lab color mode results with the results obtained through additional testing using traditional infrared reflectance and infrared luminescence test methods showed that lab color differentiated 102 pen-pair samples (11%; 102/946) that were not differentiated using a VSC-4C. [source] Electromagnetic propagation in unbounded inhomogeneous chiral media using the coupled mode methodMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2007Álvaro Gómez Abstract The coupled mode method (CMM) is a seminumerical method for studying electromagnetic propagation, originally formulated for closed structures. We show how this method can be used for obtaining the propagation constants and electromagnetic field in unbounded isotropic chiral media. We also characterize single and periodic cascade discontinuities made of isotropic chiral slabs by means of the mode matching method combined with the CMM. The results are tested with a robust FDTD technique, modified to model bi-isotropic media and with analytical solutions. In all cases good agreement is found. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2771,2779, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22863 [source] Matching the frequency spectrum of pre-main sequence stars by means of standard and rotating modelsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2008M. Di Criscienzo ABSTRACT We applied the aton evolutionary code to the computation of detailed grids of standard (non-rotating) and rotating pre-main sequence (PMS) models and computed their adiabatic oscillation spectra, with the aim of exploring the seismic properties of young stars. As, until now, only a few frequencies have been determined for ,40 PMS stars, the way of approaching the interpretation of the oscillations is not unique. We adopt a method similar to the matching mode method by Guenther and Brown making use, when necessary, also of our rotating evolutionary code to compute the models for PMS stars. The method is described by a preliminary application to the frequency spectrum of two PMS stars (85 and 278) in the young open cluster NGC 6530. For the Star 85, we confirm with self-consistent rotating models, previous interpretation of the data, attributing three close frequencies to the mode n= 4, l= 1 and m= 0, +1 and ,1. For the Star 278, we find a different fit for the frequencies, corresponding to a model within the original error box of the star, and dispute the possibility that this star has a Teff much cooler that the red boundary of the radial instability strip. [source] SECOND-ORDER TERMINAL SLIDING MODE CONTROL OF INPUT-DELAY SYSTEMSASIAN JOURNAL OF CONTROL, Issue 1 2006Yong Feng ABSTRACT This paper proposes a second-order terminal sliding mode control for a class of uncertain input-delay systems. The input-delay systems are firstly converted into the input-delay free systems and further converted into the regular forms. A linear sliding mode manifold is predesigned to represent the ideal dynamics of the system. Another terminal sliding mode manifold surface is presented to drive the linear sliding mode to reach zeros in finite time. In order to eliminate the chattering phenomena, a second-order sliding mode method is utilized to filter the high frequency switching control signal. The uncertainties of the systems are analysed in detail to show the effect to the systems. The simulation results validate the method presented in the paper. [source] | ||||||||||