• 제목/요약/키워드: numerical procedure

검색결과 2,061건 처리시간 0.027초

An analytical-numerical procedure for cracking and time-dependent effects in continuous composite beams under service load

  • Chaudhary, Sandeep;Pendharkar, Umesh;Nagpal, A.K.
    • Steel and Composite Structures
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    • 제7권3호
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    • pp.219-240
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    • 2007
  • An analytical-numerical procedure has been presented in this paper to take into account the nonlinear effects of concrete cracking and time-dependent effects of creep and shrinkage in the concrete portion of the continuous composite beams under service load. The procedure is analytical at the element level and numerical at the structural level. The cracked span length beam element consisting of uncracked zone in middle and cracked zones near the ends has been proposed to reduce the computational effort. The progressive nature of cracking of concrete has been taken into account by division of the time into a number of time intervals. Closed form expressions for stiffness matrix, load vector, crack lengths and mid-span deflection of the beam element have been presented in order to reduce the computational effort and bookkeeping. The procedure has been validated by comparison with the experimental and analytical results reported elsewhere and with FEM. The procedure can be readily extended for the analysis of composite building frames where saving in computational effort would be very considerable.

FFT를 이용한 Hertz Contact 해석 (Analysis of Hertzian Contact using Fast Fourier Transform)

  • 구영필;조용주
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1998년도 제27회 춘계학술대회
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    • pp.131-138
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    • 1998
  • In this study, a numerical procedure to solve a contact problem has been developed. The procedure takes the advantage of signal processing technique in frequency domain to achieve the shorter computer processing time. The Boussinesq's equation was adopted as the response function. This procedure is applicable to the non-periodic surface profile as well as the periodic one. The validity of this procedure has been established by comparing the numerical results with the exact solutions. The effectiveness of this procedure is lied on the shorter computing time than any other contact analysis algorithm.

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A numerical procedure for reinforced concrete columns with a focus on stability analysis

  • Pires, Susana L.;Silva, Maria Cecilia A.T.
    • Computers and Concrete
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    • 제14권6호
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    • pp.657-674
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    • 2014
  • The purpose of this paper is to present a numerical procedure to analyse reinforced concrete columns subjected to combined axial loads and bending that rigorously considers nonlinear material and nonlinear geometric characteristics. Column design and stability analysis are simultaneously regarded. A finite element method is used for calculating displacements and the material and geometric nonlinearities are taken into account using an iterative process. A computer program is developed from the proposed numerical procedure, and the efficiency of the program is verified against available experimental data. The model applies to constant rectangular cross sectional columns with symmetric reinforcement distribution.

수평곡선 격자형교의 자유진동해석 (Free Vibration Analysis of Horizontally Curved Multi-Girder Bridges)

  • 윤기용;강영종
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1996년도 가을 학술발표회 논문집
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    • pp.55-61
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    • 1996
  • In the present study, a numerical formulation procedure fer free vibration analysis of thin-walled horizontally curved multi-girder bridges is presented. The presented finite element procedure consists of curved and straight beam elements including warping degree of freedom. The homogeneous solutions of curved beam equations were used for shape functions in numerical formulation to achieve good convergence. In the straight beam element, the third order hermite polynomials were used fer shape functions. The Gupta method was used to solve the eigenvalue problem efficiently. The developed numerical procedure was applied to investigate the characteristics of free vibration of horizontally curved multi-girder bridges with varing subtended angle.

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NUMERICAL ANALYSIS PROCEDURE FOR PREDICTING TEMPERATURE FIELD IN DESIGN OF AUTOMOTIVE FRICTION CLUTCH

  • LEE B.;CHO C.
    • International Journal of Automotive Technology
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    • 제7권1호
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    • pp.61-68
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    • 2006
  • In design of the friction clutches of automobiles, knowledge on the thermo-elasticity a priori is very informative in the initial design stage. Especially, the precise prediction technique of maximum temperature and stress should be requested in design of mechanical clutches for their durability and compactness. In this study, an efficient and reliable analysis technique for the design of the mechanical clutches by using computer modeling and numerical method was developed. A commercial software STAR-$CD^{TM}$ was used to find the convective heat-transfer coefficients. MSC/$NASTRAN^{TM}$ software was followed to predict the temperature of clutch with utilization of estimated coefficients. Some experiments were also performed with a dynamometer to verify the procedure and calibrate the thermal load. As a conclusion, a design procedure, including numerical steps and experimental techniques for calibration, was proposed.

Combined influence of slip parameter and Reynolds number on Casson nanofluid flowing in stretching cylinder

  • Jalil, Mudassar;Hussain, Muzamal;Khadimallah, Mohamed A.;Iqbal, Waheed;Loukil, Hassen;Mouldi, Abir;Mahmoud, S.R.;Tounsi, Abdelouahed
    • Computers and Concrete
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    • 제30권5호
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    • pp.369-375
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    • 2022
  • Current exertion reports the numerical analysis of boundary layer slip flow of Casson Nano fluid along a permeable cylinder that is stretching in exponential manner. The modeled PDEs are changed into nonlinear ODEs through appropriate nonlinear transformations. Numerical results are attained using a renowned numerical scheme shooting method with Runge-Kutta procedure of 6th-order. Influential role of relevant parameters like Reynolds, suction, Casson fluid and slip parameters on velocity profile is investigated. The effect of influence of slip parameter γ on temperature profile is seen through graph. To ensure the authenticity of numerical procedure, outcomes of some special cases of present work are compared with published work and strong agreement is noticed.

A New FFT Technique for the Analysis of Contact Pressure and Subsurface Stress in a Semi-Infinite Solid

  • Cho, Yong-Joo;Koo, Young-Pil;Kim, Tae-Wan
    • Journal of Mechanical Science and Technology
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    • 제14권3호
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    • pp.331-337
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    • 2000
  • A numerical procedure for contact analysis and calculating subsurface stress was developed. The procedure takes the advantage of signal processing technique in frequency domain to achieve shorter computing time. Boussinesq's equation was adopted as a response function in contact analysis. The validity of this procedure was proved by comparing the numerical results with the exact solutions. The fastness of this procedure was also compared with other algorithm.

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건축 구조물의 지진응답 제어를 위해 제안된 MR감쇠기 설계 절차의 수치적 검증 (Numerical Verification of the Proposed Design Procedure of MR Damper for Seismic Response Control of Building Structure)

  • 이상현;민경원;이루지
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2005년도 학술발표회 논문집
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    • pp.521-528
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    • 2005
  • In our previous study, we have developed a preliminary design procedure of MR dampers for controlling seismic response of building structures. In this paper, the effectiveness the proposed method is verified through the numerical analysis of the structures with various period and story number, and twenty earthquake loads are used for statistical assessment. The comparison between the proposed method and simplified sequential search algorithm indicates that the capacity, number and the placement of the MR damper which can achieve the given performance objective are reasonably determined using the proposed design procedure.

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Finite element procedure of initial shape determination for hyperelasticity

  • Yamada, Takahiro
    • Structural Engineering and Mechanics
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    • 제6권2호
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    • pp.173-183
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    • 1998
  • In the shape design of flexible structures, it is useful to predict the initial shape from the desirable large deformed shapes under some loading conditions. In this paper, we present a numerical procedure of an initial shape determination problem for hyperelastic materials which enables us to calculate an initial shape corresponding to the prescribed deformed shape and boundary condition. The present procedure is based on an Arbitrary Lagrangian-Eulerian (ALE) finite element method for hyperelasticity, in which arbitrary change of shapes in both the initial and deformed states can be treated by considering the variation of geometric mappings in the equilibrium equation. Then the determination problem of the initial shape can be formulated as a nonlinear problem to solve the unknown initial shape for the specified deformed shape that satisfies the equilibrium equation. The present approach can be implemented easily to the finite element method by employing the isoparametric hypothesis. Some basic numerical results are also given to characterize the present procedure.

Comparison of Rigorous Design Procedure with Approximate Design Procedure for Variable Sampling Plans Indexed by Quality Loss

  • Ishii, Yoma;Arizono, Ikuo;Tomohiro, Ryosuke;Takemoto, Yasuhiko
    • Industrial Engineering and Management Systems
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    • 제15권3호
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    • pp.231-238
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    • 2016
  • Traditional acceptance sampling plans have focused on the proportion of nonconforming items as an attribute criterion for quality. In today's modern quality management under high quality production environments, the reduction of the deviation from a target value in a quality characteristic has become the most important purpose. In consequence, various inspection plans for the purpose of reducing the deviation from the target value in the quality characteristic have been investigated. In this case, a concept of the quality loss evaluated by the deviation from the target value has been accepted as the variable evaluation criterion of quality. Further, some quality measures based on the quality loss have been devised; e.g. the process loss and the process capability index. Then, as one of inspection plans based on the quality loss, the rigorous design procedure for the variable sampling plan having desired operating characteristics (VS-OC plan) indexed by the quality loss has been proposed by Yen and Chang in 2009. By the way, since the estimator of the quality loss obeys the non-central chi-square distribution, the rigorous design procedure for the VS-OC plan indexed by the quality loss is complicated. In particular, the rigorous design procedure for the VS-OC plan requires a large number of the repetitive and complicated numerical calculation about the non-central chi-square distribution. On the other hand, an approximate design procedure for the VS-OC plan has been proposed before the proposal of the above rigorous design procedure. The approximate design procedure for the VS-OC plan has been constructed by combining Patnaik approximation relating the non-central chi-square distribution to the central chi-square distribution and Wilson-Hilferty approximation relating the central chi-square distribution to the standard normal distribution. Then, the approximate design procedure has been devised as a convenient procedure without complicated and repetitive numerical calculations. In this study, through some comparisons between the rigorous and approximate design procedures, the applicability of the approximate design procedure has been confirmed.