• Title/Summary/Keyword: Analytical Models

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Numerical simulation of shaking table tests on 3D reinforced concrete structures

  • Bayhan, Beyhan
    • Structural Engineering and Mechanics
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    • 제48권2호
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    • pp.151-171
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    • 2013
  • The current paper presents the numerical blind prediction of nonlinear seismic response of two full-scale, three dimensional, one-story reinforced concrete structures subjected to bidirectional earthquake simulations on shaking table. Simulations were carried out at the laboratories of LNEC (Laboratorio Nacional de Engenharia Civil) in Lisbon, Portugal. The study was motivated by participation in the blind prediction contest of shaking table tests, organized by the challenge committee of the 15th World Conference on Earthquake Engineering. The test specimens, geometrically identical, designed for low and high ductility levels, were subjected to subsequent earthquake motions of increasing intensity. Three dimensional nonlinear analytical models were implemented and subjected to the input base motions. Reasonably accurate reproduction of the measured displacement response was obtained through appropriate modeling. The goodness of fit between analytical and measured results depended on the details of the analytical models.

도로교동적응답의 확률적 특성에 관한 연구 (Probabilistic Characteristics of Dynamic Responses of Highway Bridges)

  • 김상효;김종학;윤성호
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1997년도 가을 학술발표회 논문집
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    • pp.8-14
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    • 1997
  • The dynamic responses of highway bridges are varying depending on the features of either traveling vehicles or bridges. In this study, the probabilistic characteristics of dynamic amplification factors of highway bridges due to traveling heavy vehicles have been examined through analytical simulation processes. The truck with tandem axle and tractor with semitrailer are selected as the representative heavy vehicles, which are modeled with three dimensional 7-DOF and 12-DOF models, respectively. The analytical results have been compared with the experimental results of dynamic loading tests and the validity of the analytical models has been examined. Parametric studies on the means and extreme values of amplification factors have been performed with various traffic conditions such as vehicle types, vehicle weights, surface profiles, vehicle velocity, etc.

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Analytical Models of Instruction Fetch on Superscalar Processors

  • Kim, Sun-Mo;Jung, Jin-Ha;Park, Sang-Bang
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -2
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    • pp.619-622
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    • 2000
  • This research presents an analytical model to predict the instruction fetch rate on superscalar Processors. The proposed model is also able to analyze the performance relationship between cache miss and branch prediction miss. The proposed model takes into account various kind of architectural parameters such as branch instruction probability, cache miss rate, branch prediction miss rate, and etc.. To prove the correctness of the proposed model, we performed extensive simulations and compared the results with those of the analytical models. Simulation results showed that the pro-posed model can estimate the instruction fetch rate accurately within 10% error in most cases. The model is also able to show the effects of the cache miss and branch prediction miss on the performance of instruction fetch rate, which can provide an valuable information in designing a balanced system.

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Flexural and shear behaviour of profiled double skin composite elements

  • Anwar Hossain, K.M.;Wright, H.D.
    • Steel and Composite Structures
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    • 제4권2호
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    • pp.113-132
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    • 2004
  • Double skin composite element (DSCE) is a novel form of construction comprising two skins of profiled steel sheeting with an infill of concrete. DSCEs are thought to be applicable as shear or core walls in a building where they can resist in-plane loads. In this paper, the behaviour of DSCE subjected to combined bending and shear deformation is described. Small-scale model tests on DSCEs manufactured from micro-concrete and very thin sheeting were conducted to investigate the flexural and shear behaviour along with analytical analysis. The model tests provided information on the strength, stiffness, strain conditions and failure modes of DSCEs. Detailed development of analytical models for strength and stiffness and their performance validation by model tests are presented.

과도 상태 시 NPT IGBT의 전압-전류 모델링 (Voltage-Current Modeling of NPT IGBT for Transient Condition)

  • 류세환;이명수;안형근;한득영
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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    • pp.405-408
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    • 2004
  • In this work, Analytical model for voltage and current characteristics of NPT(Non-PunchThrough) IGBT(Insulated Gate Bipolar Transistor) was represented. voltage and current characteristics models were based on prediction on power loss of NPT IGBT during transient condition. For Analytical current model, excess carrier concentration and accumulated charge in active base width was analyzed with time variance. Analytical models were simulated by varying lifetime of excess minority carrier.

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Experimental and analytical study of steel slit shear wall

  • Khatamirad, Milad;Shariatmadar, Hashem
    • Steel and Composite Structures
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    • 제24권6호
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    • pp.741-751
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    • 2017
  • A steel slit shear wall has vertical slits and when it is under lateral loads, the section between these slits has double-curvature deformation, and by forming a flexural plastic hinge at the end of the slit, it dissipates the energy on the structure. In this article, Experimental, numerical and analytical analyses are performed to study the effect of slit shape and edge stiffener on the behavior of steel slit shear wall. Seismic behavior of three models with different slit shapes and two models with different edge stiffener shapes are studied and compared. Hysteresis curves, energy dissipation, out of plane buckling, initial stiffness and strength are discussed and studied. The proposed slit shape reduces the initial stiffness, increases the strength and energy dissipation. Also, edge stiffener shape increases the initial stiffness significantly.

Behaviours of steel-fibre-reinforced ULCC slabs subject to concentrated loading

  • Wang, Jun-Yan;Gao, Xiao-Long;Yan, Jia-Bao
    • Structural Engineering and Mechanics
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    • 제71권4호
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    • pp.407-416
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    • 2019
  • Novel steel fibre reinforced ultra-lightweight cement composite (ULCC) with compressive strength of 87.3MPa and density of $1649kg/m^3$ was developed for the flat slabs in civil buildings. This paper investigated structural behaviours of ULCC flat slabs according to a 4-specimen test program under concentrated loading and some reported test results. The investigated governing parameters on the structural behaviours of the ULCC slabs include volume fraction of the steel fibre and the patch loading area. The test results revealed that ULCC flat slabs with and without flexure reinforcement failed in different failure mode, and an increase in volume fraction of the steel fibre and loading area led to an increase in flexural resistance for the ULCC slabs without flexural reinforcement. Based on the experiment results, the analytical models were developed and also validated. The validations showed that the analytical models developed in this paper could predict the ultimate strength of the ULCC flat slabs with and without flexure reinforcement reasonably well.

Performance Optimization Study of FinFETs Considering Parasitic Capacitance and Resistance

  • An, TaeYoon;Choe, KyeongKeun;Kwon, Kee-Won;Kim, SoYoung
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제14권5호
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    • pp.525-536
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    • 2014
  • Recently, the first generation of mass production of FinFET-based microprocessors has begun, and scaling of FinFET transistors is ongoing. Traditional capacitance and resistance models cannot be applied to nonplanar-gate transistors like FinFETs. Although scaling of nanoscale FinFETs may alleviate electrostatic limitations, parasitic capacitances and resistances increase owing to the increasing proximity of the source/drain (S/D) region and metal contact. In this paper, we develop analytical models of parasitic components of FinFETs that employ the raised source/drain structure and metal contact. The accuracy of the proposed model is verified with the results of a 3-D field solver, Raphael. We also investigate the effects of layout changes on the parasitic components and the current-gain cutoff frequency ($f_T$). The optimal FinFET layout design for RF performance is predicted using the proposed analytical models. The proposed analytical model can be implemented as a compact model for accurate circuit simulations.

Performance analysis tool for reinforced concrete members

  • Esmaeily, Asad;Peterman, Robert J.
    • Computers and Concrete
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    • 제4권5호
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    • pp.331-346
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    • 2007
  • A computer program was developed to analyze the non-linear, cyclic flexural performance of reinforced concrete structural members under various types of loading paths including non-sequential variations in axial load. This performance is significantly affected by the loading history. Different monotonic material models as well as hysteresis rules for confined and unconfined concrete and steel, some developed and calibrated against test results on material samples, were implemented in a fiber-based moment-curvature and in turn force-deflection analysis. One of the assumptions on curvature distribution along the member was based on a method developed to address the variation of the plastic hinge length as a result of loading pattern. Functionality of the program was verified by reproduction of analytical results obtained by others for several cases, and accuracy of the analytical process and the implemented models were evaluated against the experimental results from large-scale reinforced concrete columns tested under the analyzed loading cases. While the program can be used to predict the response of a member under a certain loading pattern, it can also be used to examine various analytical models and methods or refine a custom material model against test data.

An Improved Analytical Model for Predicting the Switching Performance of SiC MOSFETs

  • Liang, Mei;Zheng, Trillion Q.;Li, Yan
    • Journal of Power Electronics
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    • 제16권1호
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    • pp.374-387
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    • 2016
  • This paper derives an improved analytical model to estimate switching loss and analyze the effects of parasitic elements on the switching performance of SiC MOSFETs. The proposed analytical model considers the parasitic inductances, the nonlinearity of the junction capacitances and the nonlinearity of the trans-conductance. The turn-on process and the turn-off process are illustrated in detail, and equivalent circuits are derived and solved for each switching transition. The proposed analytical model is more accurate and matches better with experimental results than other analytical models. Note that switching losses calculated based on experiments are imprecise, because the energy of the junction capacitances is not properly disposed. Finally, the proposed analytical model is utilized to account for the effects of parasitic elements on the switching performance of a SiC MOSFET, and the circuit design rules for high frequency circuits are given.