Journal articles: 'Move subroutine'

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Wang, Li Xia, Zhan Rong Feng, and Ran Yang Zhang. "Research on Siemens PLC Pulse Control." Advanced Materials Research 705 (June 2013): 616–20. http://dx.doi.org/10.4028/www.scientific.net/amr.705.616.

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In order to apply the PTO pulse function of Siemens PLC in a more systematic, convenient and effective way, this thesis adopts the position control wizard to generate envelop and control subroutine. The thesis also makes detailed descriptions and case discussions on the four subroutines of PTO0_CTRL, PTO0_RUN, PTO0_MAN, PTO0_LDPOS, and the results show that using the position control wizard can not only generate envelop and control subroutine conveniently but also bring convenience to the application of the subroutine. Especially, the parameters of the four subroutines interact both independently and mutually. If we make a deeper research on the parameters, we can master their relations further more and apply them more proficiently.

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Wang, Li Xia, Zhan Rong Feng, and Ze Min Liu. "Research Based on the Position Control Wizard of S7-200." Advanced Materials Research 717 (July 2013): 603–7. http://dx.doi.org/10.4028/www.scientific.net/amr.717.603.

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In order to apply the PTO pulse function of S7-200 PLC in a more systematic, convenient and effective way, this thesis adopts the position control wizard to generate envelop and control subroutine. The thesis also makes detailed descriptions and case discussions on the three subroutines of PTO0_CTRL, PTO0_RUN, PTO0_LDPOS, and the results show that using the position control wizard can not only generate envelop and control subroutine conveniently but also bring convenience to the application of the subroutine. Especially, the parameters of the three subroutines interact both independently and mutually. If we make a deeper research on the parameters, we can master their relations further more and apply them more proficiently.

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Dragoi, Danut, and Alexandru Dragoi. "Modeling of energy-dispersive X-ray diffraction for high-symmetry crystal orientation." Acta Crystallographica Section A Foundations and Advances 75, no. 1 (January 1, 2019): 63–70. http://dx.doi.org/10.1107/s2053273318013864.

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The methods for X-ray crystal orientation are rapidly evolving towards versatility, fewer goniometry measurements, automation, high accuracy and precision. One method that attracts a lot of attention is energy-dispersive X-ray diffraction (EDXRD) which is based on detecting reflections from crystallographic planes in a crystal at fixed angles of a parallel polychromatic X-ray incident beam. In theory, an EDXRD peak can move in a diffraction pattern as a function of a crystallographic plane d-spacing and its orientation relative to a fixed direction in space can change also. This is equivalent to the possibility of measuring the orientation of single crystals. The article provides a modeling for the EDXRD method whose main feature is the nonmoving crystal in the sense of traditional goniometry where the angle measurements of diffracting planes are a must. The article defines the equation of orientation for the method and shows the derivation in great detail. It is shown that the exact solutions of the equations can be obtained using the generalized reduced gradient method, a mathematical subroutine that is implemented in Excel software. The significance and scientific impact of the work are discussed along with the validated tested results.

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Aveiga, David, and Marcelo L. Ribeiro. "A Delamination Propagation Model for Fiber Reinforced Laminated Composite Materials." Mathematical Problems in Engineering 2018 (June 19, 2018): 1–9. http://dx.doi.org/10.1155/2018/1861268.

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The employment of composite materials in the aerospace industry has been gradually considered due to the fundamental lightweight and strength characteristics that this type of materials has. The science material and technological progress reached matched perfectly with the requirements for high-performance materials in aircraft and aerospace structures; thus, the development of primary structure elements applying composite materials became something very convenient. It is extremely important to pay attention to the failure modes that influence composite materials performances, since these failures lead to a loss of stiffness and strength of the laminate. Delamination is a failure mode present in most of the damaged structures and can be ruinous, considering that the evolution of interlaminar defects can carry the structure to a total failure followed by its collapse. The present work aims at the development of a delamination propagation model to estimate a progressive interlaminar delamination failure in laminated composite materials and to allow the prediction of material’s degradation due to delamination phenomenon. Experimental data, available at literature, was considered to determine some model parameters, like the strain energy release rate, using GFRPs laminated composites. This new delamination propagation model was implemented as subroutines in FORTRAN language (UMAT-User Material Subroutine) with formulations based on the Fracture Mechanics and Continuum Damage Mechanics. Finally, the UMAT subroutine was complemented with an intralaminar model and compiled beside the commercial Finite Element (FE) software ABAQUS™.

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Cui, Wei, Yanjun Luo, and Shuang Peng. "Early-Age Cracking Analysis of a HVFA Concrete Structure Based on Thermo-Hygro-Mechanical Modeling Combined with XFEM." Advances in Materials Science and Engineering 2020 (January 8, 2020): 1–13. http://dx.doi.org/10.1155/2020/5793902.

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Due to the low hydration rate of high-volume fly ash (HVFA) concrete at early age, the temperature gradient between the concrete core and surfaces could be effectively reduced. However, the low hydration rate results in a lack of hydration degree for early-age HVFA concrete. Thus, during curing, compared to the strength of ordinary Portland cement (OPC), a subsequent lower one of HVFA concrete leads to a more sensitive response to inner stresses induced by thermal and moisture loads. Based on ABAQUS, in this paper, user subroutines in the temperature and moisture fields were developed, with regard to the hydration degree, for simulation of the temperature and moisture influences on concrete. Additionally, the Double Power Law (DPL) model was used to depict early-age deformations of concrete in the mechanical field. Combined with the extended finite element method (XFEM), another subroutine for early-age cracking analysis in the mechanical field was then developed. Together with aforementioned subroutines, a thermo-hygro-mechanical model is derived. For evaluation of early-age cracking initiation and propagation of a pier composed of HVFA concrete, the model was implemented with XFEM. The obtained results show that (1) temperature and restraints are the main causes of cracking; (2) moisture loss affects surface cracks on structures at early age; and (3) although the temperature difference between the core and surfaces is not much obvious due to the reduced rate of heat dissipation from hydration, cracking of early-age HVFA concrete is still likely to happen for its low early strength. Thus, timely curing is critical to prevent early cracking.

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Muszala, S. P., D. A. Connors, J. J. Hack, and G. Alaghband. "The Promise of Load Balancing the Parameterization of Moist Convection Using a Model Data Load Index." Journal of Atmospheric and Oceanic Technology 23, no. 4 (April 1, 2006): 525–37. http://dx.doi.org/10.1175/jtech1865.1.

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Abstract The parameterization of physical processes in atmospheric general circulation models contributes to load imbalances among individual processors of message-passing distributed-multiprocessor systems. Load imbalances increase the overall time to completion of a model run and should be eliminated or reduced as much as possible. Presented herein is a new technique that shows promise for load balancing the parameterization of moist convection found in the Community Climate System Model's (CCSM's) Community Atmosphere Model version 3 (CAM3). At the heart of this technique is a load index that is a marker for moist convection (called a model data load index). The marker for moist convection correlates directly to the amount of processing time per model grid cell and can therefore be used to effect a load balance. Spatial locality on the model grid and temporal locality between model time steps exist that allow a decomposition from a load-balancing step to be retained for multiple time steps. The analysis in this paper shows that the load balance does not need to be applied at every time step and that the number of steps in which the previous load balance remains effective is large enough for the overhead to be cost effective. Tests performed indicate that this technique is scalable to higher-resolution models as well as to higher processor counts than those presented. Through the use of the Load Balancing and Scheduling Framework (LBSF), this technique shows promise in reducing (by ∼47%) the time of the unbalanced load of one particular subroutine in CAM3 at the T85 spectral truncation. A maximum of 3.75 s of total execution time is saved over a 2430-time-step simulation. When extrapolated to a 1000-yr simulation, this translates to a potential savings of ∼22 h in that subroutine alone. Similar methods applied to remaining subroutines can add up to a significant savings. These results are encouraging in that a fine-grained load-balancing technique using the evolving characteristics of geophysical data paves the way for load balancing a broad range of physical calculations, both in CAM3 and other scientific applications, where more general techniques are not practical.

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Chow, C. L., W. H. Tai, and C. T. Liu. "Prediction of Mixed-mode Fracture in Participate Composite Using a Damage Criterion." Tire Science and Technology 29, no. 2 (April 1, 2001): 79–90. http://dx.doi.org/10.2346/1.2135233.

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Abstract In this paper, a damage-coupled Mooney-Rivlin hyperelastic material model and a damage failure criterion are developed based on the theory of damage mechanics. The model is applied to predict the crack initiation angle and fracture load of particulate composite plate under mixed load. The prediction is achieved by implementing the damage model in a finite element package ABAQUS through its user-specified material subroutine. The inclined angles of the pre-crack are θ = 0, 15, 30, 45, 60, and 75°. The predictions are compared with the test results and found to be in satisfactory agreement.

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Wang, Wenming. "Strain Rate Effect on the Progressive Collapse Analysis of RC Frame Structure under Earthquake." Advances in Civil Engineering 2020 (January 22, 2020): 1–12. http://dx.doi.org/10.1155/2020/5808701.

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The strain rate effect can influence the seismic responses of reinforced concrete (RC) structures because the constitutive relationship of concrete and rebar is rate-dependent. This paper carries out progressive collapse analysis to research the influence of strain rate effects on collapse-resistant capacity, collapse mode, and collapse path of the RC frame structure. A progressive collapse simulation program for the reinforced concrete (RC) structure with a static and dynamic constitutive relationship is coded individually using the user subroutine VUMAT and then implemented in the advanced finite element program ABAQUS. The good agreement between experimental and simulation results proves that the coded subroutine is reliable. With the coded subroutine, by conducting progressive collapse analyses of a four-story RC frame structure under earthquake, the effect of strain rate on the response is investigated. The numerical results demonstrate that the collapse-resistant capacity of the structure is underestimated when the strain rate effect is neglected. It is shown that strain rate effects influence the collapse mode and collapse path of the structure. Therefore, strain rate effects should be considered in the progressive collapse analysis of the RC frame structure.

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Aranda-Ruiz, Josué, and J. A. Loya. "Numerical Analysis of the Brittle-Ductile Transition in the Failure-Mode in Polymeric Materials." Applied Mechanics and Materials 566 (June 2014): 310–15. http://dx.doi.org/10.4028/www.scientific.net/amm.566.310.

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In this paper we analyze, using the Finite Element Method, the process of brittle-ductile transition in the failure mode observed in polycarbonate notched specimens under impact loads. In order to analyze this transition we have implemented, through a user subroutine, a damage model which combines a tensional fracture criterion and an energetic, acting simultaneously. The competition between both criteria predicts the difference in material behavior from a critical impact velocity, and how this transition is produced on different planes through the thickness of the specimen. These results show the necessity of employing three-dimensional models for its study.

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Tuyttens, D. "Some more numerical experiments with LSNNO, a Fortran subroutine for solving large-scale nonlinear network optimization problems." Optimization Methods and Software 3, no. 1-3 (January 1994): 93–110. http://dx.doi.org/10.1080/10556789408805558.

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Patchamatla, J. Rama Raju, and P. K. Emani. "Time Domain Implementation of Transmitting Boundaries in ABAQUS for Discrete Soil-structure Interaction Systems." International Journal of Mathematical, Engineering and Management Sciences 5, no. 3 (June 1, 2020): 447–62. http://dx.doi.org/10.33889/ijmems.2020.5.3.037.

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Soil-structure-interaction (SSI) analyses are essential to evaluate the seismic performance of important structures before finalizing their structural design. SSI under seismic condition involves much more complex interaction with soil compared to the dynamic loads having source on the structure. Seismic SSI analysis requires due consideration of site-specific and structure-specific properties to estimate the actual ground motion (scattered motion) experienced at the base of the structure, and subsequently the effects of the scattered motion on the structure. Most challenging aspect of seismic SSI analysis is to implement transmitting boundaries that absorb the artificial reflections of stress waves at the truncated interface of the finite and infinite domains, while allowing the seismic waves to enter the finite domain. In this paper, the time domain implementation of seismic analysis of a soil-structure system is presented using classical discrete models of structure and interactive force boundary conditions for soil. These models represent typical SSI systems- a single Degree of Freedom (DOF) of a spherical cavity with mass attached to its wall, a two DOF system consisting of a mass attached by a nonlinear spring to a semi-infinite rod on elastic foundation, and a three DOF system with additional DOFs for modelling the structural stiffness and damping. The convolution integral representing the force boundary condition on the truncated interface, is evaluated interactively using UAMP user-subroutine in ABAQUS and applied as concentrated forces at the interface (truncated interface) nodes of the bounded domain or generalized-structure domain. The verification problems presented in the paper show the satisfactory performance of the developed MATLAB code and ABAQUS implementation with FORTRAN user-subroutines. The classical phenomena associated with the dynamic soil-structure systems are discussed through the present work.

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Eggleton, Peter P. "Combining Stellar Evolution and Stellar Dynamics." Symposium - International Astronomical Union 174 (1996): 213–22. http://dx.doi.org/10.1017/s0074180900001558.

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There seem to me to be four approaches to the problem of computing the evolution of star clusters. Firstly, one might assume that our knowledge of the evolution of stars can be condensed into a subroutine that can be added to an N-body code. This subroutine would mainly have to give the radius and the time-dependent mass of a star as a function of its initial mass and its age. Secondly, standing this on its head, one might assume that our knowledge of N-body evolution can be condensed into a subroutine that can be added to a stellar evolution code. This subroutine would determine, probably in a Monte-Carlo fashion, whether the star had picked up, or lost, a binary companion, or whether the orbit of its companion was significantly changed; the probabilities would be determined by simple analytic approximations to the time-dependent distribution functions of stars (and binaries) of different masses and ages, and by interaction cross-sections as functions of density and ‘temperature’. Thirdly, if the computing power is available, one might more simply unite an N-body code with a Stellar Evolution (SE) code, and follow both the dynamics and the internal evolution simultaneously. Fourthly, we might hope at some stage to put together simple analytic approximations both from N-body and from SE studies, to develop a unified simple model. I venture to say that it is only the last stage, if it is attainable, that would entitle us to say that we ‘understand’ the evolution of stellar clusters. ‘Understanding’, I think, means that we can extract some essential wisdom from large numerical simulations, and apply it on the back of the proverbial envelope.

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MAHAJAN, REEMA, DIETER KRANZLMÜLLER, JENS VOLKERT, ULRICH H. E. HANSMANN, and SIEGFRIED HÖFINGER. "DETECTING SECONDARY BOTTLENECKS IN PARALLEL QUANTUM CHEMISTRY APPLICATIONS USING MPI." International Journal of Modern Physics C 19, no. 01 (January 2008): 1–13. http://dx.doi.org/10.1142/s0129183108011899.

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Profiling tools such as gprof and ssrun are used to analyze the run-time performance of a scientific application. The profiling is done in serial and in parallel mode using MPI as the communication interface. The application is a quantum chemistry program using Hartree Fock theory and Pulays DIIS method. An extensive set of test cases is taken into account in order to reach uniform conclusions. A known problem with decreased parallel scalability can thus be narrowed down to a single subroutine responsible for the reduction in Speed Up. The critical module is analyzed and a typical pitfall with triple matrix multiplications is identified. After overhauling the critical subroutine re-examination of the run-time behavior shows significantly improved performance and markedly improved parallel scalability. The lessons learned here might be of interest to other people working in similar fields with similar problems.

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Du, Xianhe, Donghuan Liu, and Yinghua Liu. "Numerical Limit Load Analysis of 3D Pressure Vessel with Volume Defect Considering Creep Damage Behavior." Mathematical Problems in Engineering 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/204730.

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The limit load of 3D 2.25Cr-1Mo steel pressure vessel structures with volume defect at 873 K is numerically investigated in the present paper, and limit load under high temperature is defined as the load-carrying capacity after the structure serviced for a certain time. The Norton creep behavior with Kachanov-Robotnov damage law is implemented in ABAQUS with CREEP subroutine and USDFLD subroutine. Effect of dwell time to the material degradation of 2.25Cr-1Mo steel has been considered in this paper. 190 examples for the different sizes of volume defects of pressure vessels have been calculated. Numerical results showed the feasibility of the present numerical approach. It is found that the failure mode of the pressure vessel depends on the size of the volume defect and the service life of the pressure vessel structure at high temperature depends on the defect ratio seriously.

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Bures, Miroslav, Martin Filipsky, and Ivan Jelinek. "Identification of Potential Reusable Subroutines in Recorded Automated Test Scripts." International Journal of Software Engineering and Knowledge Engineering 28, no. 01 (January 2018): 3–36. http://dx.doi.org/10.1142/s0218194018500018.

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In the automated testing based on actions in user interface of the tested application, one of the key challenges is maintenance of these tests. The maintenance overhead can be decreased by suitably structuring the test scripts, typically by employing reusable objects. To aid in the development, maintenance and refactoring of these test scripts, potentially reusable objects can be identified by a semi-automated process. In this paper, we propose a solution that identifies the potentially reusable objects in a set of automated test scripts and then provides developers with suggestions about these objects. During this process, we analyze the semantics of specific test steps using a system of abstract signatures. The solution can be used to identify the potentially reusable objects in both recorded automated test sets and tests programmed in an unstructured style. Moreover, compared to approaches that are based solely on searching for repetitive source code fragments, the proposed system identifies potentially reusable objects that are more relevant for test automation.

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Liddell, Heather M., D. Parkinson, G. S. Hodgson, and P. Dzwig. "Parallel Computing Applications and Financial Modelling." Scientific Programming 12, no. 2 (2004): 81–90. http://dx.doi.org/10.1155/2004/404575.

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At Queen Mary, University of London, we have over twenty years of experience in Parallel Computing Applications, mostly on "massively parallel systems", such as the Distributed Array Processors (DAPs). The applications in which we were involved included design of numerical subroutine libraries, Finite Element software, graphics tools, the physics of organic materials, medical imaging, computer vision and more recently, Financial modelling. Two of the projects related to the latter are described in this paper, namely Portfolio Optimisation and Financial Risk Assessment.

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Gao, Qiang, Chuanxiao Liu, Jian Zhang, and Guangtan Cheng. "Simulating the Formation of Blasting-Excavation-Induced Zonal Integration in Deep Tunnels with an Elastoplastic Damage Model." Shock and Vibration 2021 (May 11, 2021): 1–18. http://dx.doi.org/10.1155/2021/9991251.

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More deep tunneling projects will be constructed due to the increasing demand of underground energy and resource. The zonal disintegration phenomena are frequently encountered with the surrounding rock of deep tunnels. To explain the mechanisms underlying the formation of zonal disintegration, an elastoplastic damage model and failure criterion are proposed in this study based on the strain gradient theory and the damage property of rock mass. A coupling calculation subroutine is thereafter developed by the ABAQUS code. The dynamic formation and development regularity of zonal disintegration in the deep tunnel are simulated by this subroutine. The radial displacement, radial stress, and tangential stress show the oscillated variation of peaks and troughs alternately. The coupling effect of the blasting load and the initial geostress transient unloading leads to the variation of alternation oscillation in the surrounding rock stress field, which is an important reason for the zonal disintegration of the surrounding rock. The morphological characteristics of fractured zones and nonfractured zones obtained from numerical simulations are in good agreement with the results from the in situ observations, which confirm the correctness and feasibility of the damage and numerical approach. The method proposed in the current study can be utilized to provide a basis for the prediction and supporting design of fractured modes.

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Sang, Jian Bing, Su Fang Xing, Xiao Lei Li, and Jie Zhang. "Nonlinear Finite Element Analysis of Crack Tip of Rubber-Like Material." Key Engineering Materials 353-358 (September 2007): 1013–16. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.1013.

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It has been well known that rubber-like material can undergo large deformation and exhibit large nonlinear elastic behavior. Because of the geometrically nonlinear of rubber like material, it is more difficult to analyze it with finite element near the notch tip. What is more, because there are varieties of the strain energy functions, implementation of these models in a general finite element program to meet the need of industry applications can be time consuming. In order to make use of the constitutive equation of Y.C. Gao in 1997 and analyze the notch tip of rubber-like material, a framework to implement the rubber-like material model is established within the general-purpose finite element program MSC.Marc. It will be very convenient to implement this isotropic hyperelastic model into the program with a user subroutine. This paper starts with the theoretical analysis based on the strain energy function given by Y.C. Gao in 1997. A user subroutine is programmed to implement this strain energy function into the program of MSC.Marc, which offer a convenient method to analyze the stress and strain of rubber-like material with the strain energy function that is needed. Though analysis with MSC.Marc, it is found that the result with finite element is consistent with the analytical result that given by Y.C. Gao in 1997, which testify that analyzing rubber like material with this method is reasonable and convenient.

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Ristić, Svetlana, S. He, Albert Van Bael, and Paul van Houtte. "Texture-Based Explicit Finite-Element Analysis of Sheet Metal Forming." Materials Science Forum 495-497 (September 2005): 1535–40. http://dx.doi.org/10.4028/www.scientific.net/msf.495-497.1535.

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An explicit integration algorithm using a texture-based plastic potential and isotropic hardening has been developed and implemented into a commercial explicit finite-element software program through a user material subroutine (VUMAT in ABAQUS/Explicit). Simulations of cup drawing of an IF-steel are presented and compared to both experimental data and calculation results obtained with a previously developed fully implicit approach (UMAT in ABAQUS/Standard). The explicit formulation has the advantage of being more stable, but local sheet thickness variations cannot be reproduced with the same accuracy.

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Gao, Na. "Effect of Initial Temperature on Free Radicals of Gas Explosion in Restricted Space." Advanced Materials Research 798-799 (September 2013): 138–42. http://dx.doi.org/10.4028/www.scientific.net/amr.798-799.138.

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The SENKIN subroutine package of CHEMKIN chemical kinetics package was used to analyze the gas explosion at three initial temperatures of 1000K, 1050K and 1100K in restricted space, based on the detailed chemical kinetics mechanism of methane combustion. The changes of explosion temperature, explosion pressure and free radicals O, H and OH generated were discussed. The results show that with elevated initial temperature, the explosion temperature increases, while the explosion pressure decreases, and the ignition delay time is shortened. Moreover, the higher the initial temperature is, the higher the mole fraction of free radicals is.

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Zhou, Song, Zhen Qing Wang, Ji Feng Zhang, and Yong Gang Xie. "Influence of Ply Angle on Failure Response of Bolted Composite Joint." Advanced Materials Research 383-390 (November 2011): 7128–32. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.7128.

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A three-dimensional model of bolted single-lap composite joint was developed to investigate the influence of ply angle on failure response of joint. This model can predict the failure mode and failure load of joint with arbitrary ply angle. The property analysis of joint was performed by using the ABAQUS FE code. Failure response and degradation of material properties were implemented using a progressive model, which is incorporated in ABAQUS USDFLD subroutine. The progressive model utilizes a set of stress-based three-dimensional Hashin criteria and a set of appropriate degradation rules.

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Nocedal, Jorge. "Theory of algorithms for unconstrained optimization." Acta Numerica 1 (January 1992): 199–242. http://dx.doi.org/10.1017/s0962492900002270.

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A few months ago, while preparing a lecture to an audience that included engineers and numerical analysts, I asked myself the question: from the point of view of a user of nonlinear optimization routines, how interesting and practical is the body of theoretical analysis developed in this field? To make the question a bit more precise, I decided to select the best optimization methods known to date – those methods that deserve to be in a subroutine library – and for each method ask: what do we know about the behaviour of this method, as implemented in practice? To make my task more tractable, I decided to consider only algorithms for unconstrained optimization.

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Xue, He, Zheng Wang, Shuai Wang, Jinxuan He, and Hongliang Yang. "Characterization of Mechanical Heterogeneity in Dissimilar Metal Welded Joints." Materials 14, no. 15 (July 26, 2021): 4145. http://dx.doi.org/10.3390/ma14154145.

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Dissimilar metal welded joints (DMWJs) possess significant localized mechanical heterogeneity. Using finite element software ABAQUS with the User-defined Material (UMAT) subroutine, this study proposed a constitutive equation that may be used to express the heterogeneous mechanical properties of the heat-affected and fusion zones at the interfaces in DMWJs. By eliminating sudden stress changes at the material interfaces, the proposed approach provides a more realistic and accurate characterization of the mechanical heterogeneity in the local regions of DMWJs than existing methods. As such, the proposed approach enables the structural integrity of DMWJs to be analyzed in greater detail.

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El-Mahlawy, Mohamed H., Sherif Hussein, and Gouda I. Mohamed. "New Hybrid-Based Self-Test Strategy for Faulty Modules of Complex Microcontroller Systems." Electronics ETF 22, no. 2 (September 19, 2019): 59. http://dx.doi.org/10.7251/els1822059e.

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In this paper, a new hybrid test strategy, called hybrid-based self-test (HYBST), is presented to test complex digital circuits such as microcontrollers. This test strategy integrates the signature multi-mode hardware-based self-test (SM-BST) with the software-based self-test (SBST). In this test strategy, the microcontroller is divided into a number of main modules, and then test subroutines are used to functionally test each module, based on its instruction set architecture (ISA). The ISA is used to generate test subroutines that represent test pattern generators (TPGs) and part of the test controller. The SMHBST represents the other part of the test controller and the test response compaction (TRC). The experimental results illustrate the superiority of the HYBST in the memory utilization, test application time, testing of internal modules of the microcontroller, and testing of general-purpose input-output (GPIO) pins of the microcontroller. In addition, an integrated test solution for fault diagnosis of the circuit boards including random logic integrated circuits (ICs) and microcontroller chips is presented to indicate a real practical test strategy.

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Pain, Jean-Christophe. "Super Transition Arrays: A Tool for Studying Spectral Properties of Hot Plasmas." Plasma 4, no. 1 (January 8, 2021): 42–64. http://dx.doi.org/10.3390/plasma4010002.

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For the theoretical study of X and extreme-UV spectra of ions in plasmas, quantum mechanics brings more detailed results than statistical physics. However, it is impossible to handle individually the billions of levels that must be taken into account in order to properly describe hot plasmas. Such levels can be gathered into electronic configurations or superconfigurations (groups of configurations) and the corresponding calculations rely on appropriate statistical methods, for local or non-local thermodynamic equilibrium plasmas. In this article we present the basic principles of the Super-Transition-Array approach as well as its practical implementation. During the last decades, calculations performed with the SCO code (Superconfiguration Code for Opacity) have been compared to opacity measurements. The code includes static screening of ions by plasma and is well suited for studying plasma density effects (for example pressure ionization) on opacity and equation of state. The recently developed SCO-RCG code (Superconfiguration Code for Opacity combined with Robert Cowan’s “G” subroutine) combines statistical methods from SCO and fine-structure (detailed-level-accounting) calculations using subroutine RCG from Cowan’s code. SCO-RCG enables us to obtain very detailed spectra and to significantly improve the interpretation of experimental spectra. The Super-Transition-Array formalism is still the cornerstone of several opacity codes, and new ideas are emerging, such as the Configurationally Resolved-Super-Transition-Array approach or the extension of the Partially Resolved-Transition-Array concept to the superconfiguration method.

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YAO, JUN, YUFENG YAO, ANTONINO ARINI, STUART MCIIWAIN, and TIMOTHY GORDON. "MODELLING AIR AND WATER TWO-PHASE ANNULAR FLOW IN A SMALL HORIZONTAL PIPE." International Journal of Modern Physics: Conference Series 42 (January 2016): 1660158. http://dx.doi.org/10.1142/s2010194516601587.

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Numerical simulation using computational fluid dynamics (CFD) has been carried out to study air and water two-phase flow in a small horizontal pipe of an inner diameter of 8.8mm, in order to investigate unsteady flow pattern transition behaviours and underlying physical mechanisms. The surface liquid film thickness distributions, determined by either wavy or full annular flow regime, are shown in reasonable good agreement with available experimental data. It was demonstrated that CFD simulation was able to predict wavy flow structures accurately using two-phase flow sub-models embedded in ANSYS-Fluent solver of Eulerian–Eulerian framework, together with a user defined function subroutine ANWAVER-UDF. The flow transient behaviours from bubbly to annular flow patterns and the liquid film distributions revealed the presence of gas/liquid interferences between air and water film interface. An increase of upper wall liquid film thickness along the pipe was observed for both wavy annular and full annular scenarios. It was found that the liquid wavy front can be further broken down to form the water moisture with liquid droplets penetrating upwards. There are discrepancies between CFD predictions and experimental data on the liquid film thickness determined at the bottom and the upper wall surfaces, and the obtained modelling information can be used to assist further 3D user defined function subroutine development, especially when CFD simulation becomes much more expense to model full 3D two-phase flow transient performance from a wavy annular to a fully developed annular type.

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Pain, Jean-Christophe. "Super Transition Arrays: A Tool for Studying Spectral Properties of Hot Plasmas." Plasma 4, no. 1 (January 8, 2021): 42–64. http://dx.doi.org/10.3390/plasma4010002.

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For the theoretical study of X and extreme-UV spectra of ions in plasmas, quantum mechanics brings more detailed results than statistical physics. However, it is impossible to handle individually the billions of levels that must be taken into account in order to properly describe hot plasmas. Such levels can be gathered into electronic configurations or superconfigurations (groups of configurations) and the corresponding calculations rely on appropriate statistical methods, for local or non-local thermodynamic equilibrium plasmas. In this article we present the basic principles of the Super-Transition-Array approach as well as its practical implementation. During the last decades, calculations performed with the SCO code (Superconfiguration Code for Opacity) have been compared to opacity measurements. The code includes static screening of ions by plasma and is well suited for studying plasma density effects (for example pressure ionization) on opacity and equation of state. The recently developed SCO-RCG code (Superconfiguration Code for Opacity combined with Robert Cowan’s “G” subroutine) combines statistical methods from SCO and fine-structure (detailed-level-accounting) calculations using subroutine RCG from Cowan’s code. SCO-RCG enables us to obtain very detailed spectra and to significantly improve the interpretation of experimental spectra. The Super-Transition-Array formalism is still the cornerstone of several opacity codes, and new ideas are emerging, such as the Configurationally Resolved-Super-Transition-Array approach or the extension of the Partially Resolved-Transition-Array concept to the superconfiguration method.

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Mäntylä, Antti, Jussi Göös, Anton Leppänen, and Tero Frondelius. "Large bore engine connecting rod fretting analysis." Rakenteiden Mekaniikka 50, no. 3 (August 21, 2017): 239–43. http://dx.doi.org/10.23998/rm.64914.

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A detailed contact analysis of a large connecting rod was performed to evaluatethe fretting risk in the big end. Simulation was carried out in Abaqus considering all relevantboundary conditions, such as assembly loads, housing machining and dynamics from a exiblemultibody simulation with elastohydrodynamic bearings. Being one of the most importantvariables, the local coeffcient of friction (COF) and its evolution is calculated during the solutionby using a subroutine in Abaqus. The model is validated by strain gauge measurements in arunning engine. The resulted friction coefficient distribution matches well with the ndings froma laboratory engine. The described methodology increases the accuracy of the fretting damageprediction by using a more realistic friction coefficient denition.

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29

Wang, Shi Xun, Lin Zhi Wu, and Li Ma. "Low-Velocity Impact Characteristics of Carbon Fiber Composites Lattice Core Sandwich Structures." Advanced Materials Research 79-82 (August 2009): 127–30. http://dx.doi.org/10.4028/www.scientific.net/amr.79-82.127.

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Since composite sandwich structures are susceptible to low-velocity impact damage, a thorough characterization of the loading and damage process during impact is important. In the present paper, the low-velocity impact response of carbon fiber composites lattice structures are investigated by experimental and numerical methods. Impact tests on composite plates are performed using an instrumented drop-weight machine (Instron 9250HV) and a new damage mode is observed. A three-dimensional finite element model is built by ABAQUS/Explicit and user subroutine (VUMAT) to predict the peak loading and simulate the complicated damage problem. It can be found that numerical predictions coincide well with experimental results.

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Cai, Guoqing, Bowen Han, Mengzi Li, Kenan Di, Yi Liu, Jian Li, and Tianchi Wu. "Numerical Implementation of a Hydro-Mechanical Coupling Constitutive Model for Unsaturated Soil Considering the Effect of Micro-Pore Structure." Applied Sciences 11, no. 12 (June 9, 2021): 5368. http://dx.doi.org/10.3390/app11125368.

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An unsaturated soil constitutive model considering the influence of microscopic pore structure can more accurately describe the hydraulic–mechanical behavior of unsaturated soil, but its numerical implementation is more complicated. Based on the fully implicit Euler backward integration algorithm, the ABAQUS software is used to develop the established hydro-mechanical coupling constitutive model for unsaturated soil, considering the influence of micro-pore structure, and a new User-defined Material Mechanical Behavior (UMAT) subroutine is established to realize the numerical application of the proposed model. The developed numerical program is used to simulate the drying/wetting cycle process of the standard triaxial specimen. The simulation results are basically consistent with those calculated by the Fortran program, which verifies the rationality of the developed numerical program.

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He, Yan Li, Hai Ying Ma, and Jing Yi Wang. "Chip Formation Simulation in FE Modeling for Machining FRP Composite." Advanced Materials Research 690-693 (May 2013): 2422–26. http://dx.doi.org/10.4028/www.scientific.net/amr.690-693.2422.

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The influence of chip formation technology on the simulation of machining unidirectional fiber reinforced polymer composite (FRP) is investigated. Two-dimensional macro-mechanical FE model was developed for orthogonal machining. Tsai-Hill failure criterion was implemented in VUMAT Abaqus subroutine. Two different chip formation technologies were simulated, analyzed and compared with experiment in literature. The results show that chip formation technology makes a difference in FRP machining simulation for various cutting conditions. Though chip shape, cutting forces and sub surface damages predicted by ALE model are more reasonable than that by element deletion model, predictions in both models are not satisfactory due to inherent limitations associated with the macro mechanical FE model and Tsai-Hill damage criterion.

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32

Wang, Zhong Qiu, J. Sun, Jian Feng Li, and I. Al-Zkeri. "Prediction of Residual Stress in Hard Turning of AISI 52100 Using 2D FEM." Applied Mechanics and Materials 10-12 (December 2007): 688–91. http://dx.doi.org/10.4028/www.scientific.net/amm.10-12.688.

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Residual stress on the machined surface and the subsurface is one of the most important factors that can influence the service quality of a component, such as fatigue life, tribological properties, and distortion. In this work, a 2D FEM model of AISI 52100 hard turning processes is setup. The material properties are widely selected to describe the material property more precisely. By using user subroutine named Konti-Cut, the steady state of cutting process is simulated and the cutting forces and residual stresses in this time are investigated. By comparing the cutting forces, the FEM model can gives quite good appliance with experimental data. And the basic relations between residual stresses and cutting parameter, tool geometry are drawn.

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33

Zhou, Yan Qun, Mei Xin Ye, Zhi Shuo Yang, and Li Ou. "Hysteresis Analysis of RC Columns Based on Fiber Cross-Section Model." Advanced Materials Research 255-260 (May 2011): 3770–74. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.3770.

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The seismic performance of reinforced concrete(RC) columns is one of the controlling factors of the shock resistance for RC frame structures and bridges under seismic loads. Due to the complicated material behavior and complex external force during the earthquake, an accurate simulation of the mechanical performance under seismic loads demands more precisions for the hysteresis constitutive laws of materials. In this paper, based on the fiber cross-section model, adopting revised Kent-Park model for concrete and Legeron model for steel reinforcement, programming the UMAT material subroutine, FEM software ABAQUS is used to simulate a RC column mentioned in a research. It’s results are found agreed well with the test results.

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34

Shen, Qiuyi, Zhenghao Zhu, and Yi Liu. "Progressive failure analysis of scarf-repaired composite laminate based on damage constitutive model." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 233, no. 2 (October 3, 2016): 180–88. http://dx.doi.org/10.1177/1464420716666400.

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A three-dimensional finite element model for scarf-repaired composite laminate was established on continuum damage model to predict the load capacity under tensile loading. The mixed-mode cohesive zone model was adopted to the debonding behavior analysis of adhesive. Damage condition and failure of laminates and adhesive were subsequently addressed. A three-dimensional bilinear constitutive model was developed for composite materials based on damage mechanics and applied to damage evolution and loading capacity analyses by quantifying damage level through damage state variables. The numerical analyses were implemented with ABAQUS finite element analysis by coding the constitutive model into material subroutine VUMAT. Good agreement between the numerical and experimental results shows the accuracy and adaptability of the model.

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35

Zhang, Ting Fang, and Shi Kun Xie. "Study on Formability about ME20M Magnesium Alloy Sheet." Advanced Materials Research 136 (October 2010): 23–27. http://dx.doi.org/10.4028/www.scientific.net/amr.136.23.

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Warm forming of magnesium alloy sheet has attracted more and more attention in recent years. Mechanics tension test has been made in this paper in order to study the constitutive relationship of ME20M magnesium alloy sheet at different temperatures and strain rates. And a constitutive relationship which includes a softening factor has been put forward. Warm deep drawing experiment and numerical simulation on ME20M magnesium alloy sheet have been made in which the attention was focused on the forming temperature. The results showed that the limit deep drawing height of ME20M magnesium alloy sheet can be dramatically improved as the temperature goes up, especially when the temperature was over about 250°C. Simultaneity, it is feasible and effective to add a material model into numerical simulation software by user subroutine.

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36

Okada, Kenji, and Ploenpit Boochathum. "DS5: direct-searcher automatic system version 5 for small molecules running on Windows personal computers." Journal of Applied Crystallography 38, no. 5 (September 15, 2005): 842–46. http://dx.doi.org/10.1107/s0021889805018571.

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DS5(Direct-Searcher Automatic System Version 5), for the crystal structure analysis of small molecules on personal computers (PCs), is a new program that integrates more than 18 main programs, subroutines and mathematics/graphic libraries of theDS*SYSTEM4package. Three features of note are: compatibility of input instruction data with theSHELXseries, control of calculation sequences by subprogram names that are prepared by the user, and graphical output on the PC display with Postscript/HPGL files. All functions ofDS5are inherited fromDS*SYSTEM4.

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37

Zhan, Zaifu, Shen Wang, Songling Huang, Yang Zheng, Fuping Wang, and Wei Zhao. "Assessment of Material Dislocation Damage by Nonlinear Ultrasound." MATEC Web of Conferences 316 (2020): 01001. http://dx.doi.org/10.1051/matecconf/202031601001.

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Under harsh environment or during service, the mechanical properties of materials or structure will deteriorate. Most of the simulations exhibit the phenomenon of nonlinearity by introducing the actual small defects, without considering dislocation. In this manuscript, subroutines are written to change the mechanical constitutive behaviour of materials. When the mechanical constitutive behaviour of the material is not linear any more, it is found that the propagation of ultrasonic wave in the material will show more obvious nonlinear phenomenon. Furthermore, the nonlinear detection coefficient is used to characterize the increase of harmonic components. This work provides a new idea for nonlinear ultrasonic testing.

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38

Yoon, Donghyun, Sangdeok Kim, Jaehoon Kim, and Youngdae Doh. "Development and Evaluation of Crack Band Model Implemented Progressive Failure Analysis Method for Notched Composite Laminate." Applied Sciences 9, no. 24 (December 17, 2019): 5572. http://dx.doi.org/10.3390/app9245572.

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Progressive failure analysis (PFA) is widely used to predict the failure behavior of composite materials. As a structure becomes more complex with discontinuities, prediction of failure becomes more difficult and mesh dependence must be taken into account. In this study, a PFA model was developed using the Hashin failure criterion and crack band model. The failure initiation was evaluated using the Hashin failure criterion. If failure initiation occurred, the damage variables at each failure mode (fiber tension and compression; matrix tension and compression) were calculated according to linear softening degradation and they were then used to derive the damaged stiffness matrix. This matrix reflected a degraded material, and PFA was continued until the damage variables became “1,” implying complete material failure. A series of processes were performed using the finite element method program ABAQUS with a user-defined material subroutine. To evaluate the proposed PFA model, experimental results of open-hole composite laminate tests were compared with the obtained numerical results. The strain behaviors were compared using a digital image correlation system. The obtained numerical results were in good agreement with the experimental ones.

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39

Hohenberger, Travis W., Richard J. Windslow, Nicola M. Pugno, and James J. C. Busfield. "A CONSTITUTIVE MODEL FOR BOTH LOW AND HIGH STRAIN NONLINEARITIES IN HIGHLY FILLED ELASTOMERS AND IMPLEMENTATION WITH USER-DEFINED MATERIAL SUBROUTINES IN ABAQUS." Rubber Chemistry and Technology 92, no. 4 (October 1, 2019): 653–86. http://dx.doi.org/10.5254/rct.19.80387.

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ABSTRACT Strain energy functions (SEFs) are used to model the hyperelastic behavior of rubberlike materials. In tension, the stress–strain response of these materials often exhibits three characteristics: (i) a decreasing modulus at low strains (<20%), (ii) a constant modulus at intermediate strains, and (iii) an increasing modulus at high strains (>200%). Fitting an SEF that works in each regime is challenging when multiple or nonhomogeneous deformation modes are considered. The difficulty increases with highly filled elastomers because the small strain nonlinearity increases and finite-extensibility occurs at lower strains. One can compromise by fitting an SEF to a limited range of strain, but this is not always appropriate. For example, rubber seals in oilfield packers can exhibit low global strains but high localized strains. The Davies–De–Thomas (DDT) SEF is a good candidate for modeling such materials. Additional improvements will be shown by combining concepts from the DDT and Yeoh SEFs to construct a more versatile SEF. The SEF is implemented with user-defined material subroutines in Abaqus/Standard (UHYPER) and Abaqus/Explicit (VUMAT) for a three-dimensional general strain problem, and an approach to overcome a mathematically indeterminate stress condition in the unstrained state is derived. The complete UHYPER and VUMAT subroutines are also presented.

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40

Li, Dong, and Demin Wei. "Rate-Dependent Cohesive Zone Model for Fracture Simulation of Soda-Lime Glass Plate." Materials 13, no. 3 (February 6, 2020): 749. http://dx.doi.org/10.3390/ma13030749.

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In this paper, rate-dependent cohesive zone model was established to numerical simulate the fracture process of soda-lime glass under impact loading. Soda-lime glass is widely used in architecture and automobile industry due to its transparency. To improve the accuracy of fracture simulation of soda-lime glass under impact loading, strain rate effect was taken into consideration and a rate-dependent cohesive zone model was established. Tensile-shear mixed mode fracture was also taken account. The rate-dependent cohesive zone model was implemented in the commercial finite element code ABAQUS/Explicit with the user subroutine VUMAT. The fracture behavior of a monolithic glass plate impacted by a hemispherical impactor was simulated. The simulation results demonstrated that the rate-dependent cohesive zone model is more suitable to describe the impact failure characteristics of a monolithic glass plate, compared to cohesive zone model without consideration of strain rate. Moreover, the effect of the strain rate sensitivity coefficient C, the mesh size of glass plate and the impact velocity on the fracture characteristics were studied.

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41

Zhang, Jian Yu, Ming Li, Li Bin Zhao, and Bin Jun Fei. "Failure Analysis of CCF300/5428 Laminates under Low Velocity Impact Based on Properties of Advanced Composite Material." Applied Mechanics and Materials 387 (August 2013): 185–88. http://dx.doi.org/10.4028/www.scientific.net/amm.387.185.

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A progressive damage model (PDM) composed by 3D FEM, Hashin and Ye failure criteria and Changs degradation rules was established to deeply understand the failure of a new material system CCF300/5428 under low velocity impact. User defined subroutines were developed and embedded into the general FEA software package to carry out the failure analysis. Numerical simulations provide more information about the failure of composite laminates under low velocity impact, including initial damage status, damage propagation and final failure status. The history of the impact point displacement and various damage patterns were detailed studied.

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42

Zhang, Li, Yong Qi Yang, and Xian Bin Tao. "The Elastic-Plastic Analysis of Functionally Graded Plate." Applied Mechanics and Materials 275-277 (January 2013): 1040–44. http://dx.doi.org/10.4028/www.scientific.net/amm.275-277.1040.

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The elastic and plastic properties of functionally graded materials in our model are assumed to abide by the mixing law and a program package is developed based on the material subroutines in ABAQUS. Using this package, an elastic-plastic analysis is performed to study a plate made of functionally graded materials. Results of a flexible design and an elastic-plastic design, and those of a continuous structure and a layered structure are compared. It is found that the elastic-plastic design is more reasonable than the flexible design and the continuous structure is more in line with the design concept of functionally graded materials.

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43

Zhan, Zaifu, Shen Wang, Fuping Wang, Songling Huang, Wei Zhao, and Zhe Wang. "Simulation of Three Constitutive Behaviors Based on Nonlinear Ultrasound." Applied Sciences 10, no. 6 (March 13, 2020): 1982. http://dx.doi.org/10.3390/app10061982.

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Nonlinear ultrasound has attracted more and more attention. In classical acoustic nonlinear theory, the source of nonlinearity is the change of constitutive relation of materials. Structure response that distorts after a single tone ultrasound wave is important to detect imperfection. This is rarely found in current simulations. The current simulation always introduces defects which do not match to the classical acoustic nonlinear theory. In this manuscript, the recurrence expressions of three kinds of imperfect materials for subroutine are given. The verifying simulation model that is used for verifying recurrence equations and wave propagation model that are used for analysing the process of ultrasonic propagation are established. The results show that the two constitutive models are effective in the verifying simulation and the hysteresis material has some special characteristics. Finally, ultrasonic propagation in two types of materials produce the expected harmonics, which build foundations for simulations of nonlinear ultrasound.

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44

Behravesh, Seyed Behzad, Hamid Jahed, Steve B. Lambert, and Mi Chengji. "Constitutive Modeling for Cyclic Behavior of AZ31B Magnesium Alloy and its Application." Advanced Materials Research 891-892 (March 2014): 809–14. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.809.

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Fatigue testing was conducted on AZ31B-H24 magnesium alloy in strain-control condition. An unusual asymmetric shape of the hysteresis loop was the key feature of the cyclic behavior. A continuum-based cyclic plasticity model was developed to follow the asymmetric hardening behavior of wrought magnesium alloys. The proposed model was implemented in a UMAT subroutine to run with Abaqus/Standard. It was demonstrated that the UMAT was able to follow the cyclic hardening behavior of AZ31B under uniaxial loading. An energy-based damage parameter was proposed for estimating the fatigue crack initiation life. The developed UMAT along with the proposed damage parameter were used for fatigue modeling of an automotive substructure made of magnesium. It was shown that the proposed asymmetric model was more promising than a symmetric model.

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45

Hoang, Nguyen Hieu, and Magnus Langseth. "Aluminium Self-Piercing Rivet's Failure: Testing and Numerical Analyses." Applied Mechanics and Materials 541-542 (March 2014): 1355–59. http://dx.doi.org/10.4028/www.scientific.net/amm.541-542.1355.

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In the present study, the behaviour of aluminium rivets in alloy AA7278-T6 during the riveting process when used to join two aluminium plates was investigated experimentally and numerically. It was observed by Hoang et al. that a rivet in alloy AA7278-T6 may fracture in shear when undergoing high pressure during the riveting process. A damage-based failure model was adopted for studying the shear fracture behaviour of the rivet. A calibration procedure of the damage parameters was suggested based on two tests (i.e. material tension tests and rivet compression tests). The model was implemented in the finite element code LS-DYNA as a user-defined subroutine. Numerical results showed that the model seemed to be able to capture the shear fracture mode in the rivets as observed in the tests.

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46

Liu, Bin, Zhen Li, Fei Xu, and Masanori Kikuchi. "Influence and Sensitivity of Inertial Effect on Void Growth Behavior in Ductile Metals." Key Engineering Materials 462-463 (January 2011): 449–54. http://dx.doi.org/10.4028/www.scientific.net/kem.462-463.449.

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This paper presents the dynamic growth behavior of the voids in ductile metals under dynamic loading condition. Started from energy conservation law, a dynamic damage model on void growth process is developed, in which inertial effect is taken into account. The proposed model on void growth is introduced into Gurson model through VUMAT subroutine, so the void growth behavior affected by inertial effect can be investigated and compared. Numerical analysis shows that inertial effect decreases the rate of void growth, and with the increasing of the loading rate, the decreasing effect becomes more remarkable. Inertial effect is very sensitive to the initial damage of the material and the distribution of the void density. The larger the initial damage and the sparser the void density, the stronger the inertial effect on the void growth.

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47

Qiu, Li Jun, Jun Wen, and Hong Zhuan Cai. "The Development of a Equipment Repair and Identification Management System." Applied Mechanics and Materials 513-517 (February 2014): 2919–22. http://dx.doi.org/10.4028/www.scientific.net/amm.513-517.2919.

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This paper designs a meet the requirements of equipment repair information management system, to realize the scientific management of instruments and equipments. Based on RFID technology, database technology, information processing and transmission technology, we aimed to systemize the management over the equipment. The test showed that, the designed system meets the requirements, design management process equipment is stable and reliable, through the serial port and the read and write tag subroutine to achieve a good exchange of electronic tags and database information, and has the advantages of simple operation, convenient use, safety and protection measures of powerful and perfect. This system can greatly improve the working efficiency of the instrument and equipment management, equipment information management more accurate, standard and perfect, to meet the need of dynamic management of equipment effectively.

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48

Ellam, D. J., R. J. Atkin, and W. A. Bullough. "Analysis of a smart clutch with cooling flow using two-dimensional bingham plastic analysis and computational fluid dynamics." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 219, no. 8 (December 1, 2005): 639–52. http://dx.doi.org/10.1243/095765005x31306.

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Two-dimensional (orthogonal) steady isothermal flows of a Bingham plastic between two plates, one moving and the other stationary, are discussed. This is done principally to examine and quantify the concept of cooling a smart clutch by throughflow. The fluid is modelled conventionally as an ideal Bingham plastic to verify the subsequent use of a computational fluid dynamics (CFD) package for similar flows in more complex situations but with a futuristic view to including heat transfer, electrical conductance, thermal and shear rate effects on fluid properties, and unsteady motion. The CFD (Fluent) package incorporates a user-defined subroutine facility which allows non-Newtonian constitutive models to be incorporated. Both radial and concentric geometries are considered. The two approaches (conventional analysis and CFD) are seen to complement one another.

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49

Wang, Chong Lin. "A Solution for Diffusion Equations and the Distribution of Alloying Elements in Sintered Alloys." Materials Science Forum 534-536 (January 2007): 481–84. http://dx.doi.org/10.4028/www.scientific.net/msf.534-536.481.

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The error function can be calculated based on the Simpson method through a subroutine program. An integration program by FORTRAN language was made for diffusion equations of extended source with infinite extent and limited extent. The distribution curves of alloying elements could be driven from calculated results written in ASCII code. The results on some alloying elements such as C, Co, Cr, Mn, Mo, Ni and V’s diffusion in iron, showed the diffusion distance for Ni and Mo can only be 1~3 μm and more distance for Co at common sintering temperature of 1120°C. Increasing the sintering temperature up to 1300°C, distribution curve could be improved. To refine the particle size of the added elements down to a scale of micrometers is an effective way to get homogeneous distribution.

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50

Guibula, Karim, Jean Louis Zerbo, M’Bi Kaboré, and Frédéric Ouattara. "Critical Frequency foF2 Variations at Korhogo Station from 1992 to 2001 Prediction with IRI-2012." International Journal of Geophysics 2019 (November 20, 2019): 1–11. http://dx.doi.org/10.1155/2019/2792101.

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In this paper we report the foF2 data measured at Korhogo station (Lat. 9.3° N; Long. 354.6° E; dip. 0.6° S) compared to predictions with IRI-2012 subroutine URSI and CCIR for different solar cycle phases (minimum, ascending, maximum, descending) and different geomagnetic activity classes (quiet, fluctuating, recurrent, shock). According to our investigations, predictions with IRI are in agreement with the measured data during daytime and show significant differences between them at night-time and especially before sunrise. Except at solar minimum, the gap between predictions and measured data are more appreciable during recurrent and shock conditions compared to quiet and fluctuating conditions. Our results also show that only URSI model expresses the signature of EXB drift phenomenon at solar maximum phase during the recurrent days and at ascending phase for fluctuating activity.

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Journal articles on the topic 'Move subroutine'

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