• Steel and Composite Structures
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• v.18 no.4
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• pp.947-970
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• 2015

An equivalent friction element is proposed to simulate the friction in cable-strut joints. Equivalent stiffness matrixes and load vectors of the friction element are derived and are unified into patterns for FEM by defining a virtual node specially to store internal forces. Three approaches are described to verify the rationality of the new equivalent friction element: applying the new element in a cable-roller model, and numerical solutions match well with experimental results; applying the element in a continuous sliding cable model, and theoretical values, numerical and experimental results are compared; and the last is applying it in truss string structures, whose results indicate that there would be a great error if the cable of cable supported structures is simulated with discontinuous cable model which is usually adopted in traditional finite element analysis, and that the prestress loss resulted from the friction in cable-strut joints would have adverse effect on the mechanical performance of cable supported structures.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.5
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• pp.421-428
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• 2009

In this study, an equivalent plate element model has been developed for an efficient vibration analysis of a biaxial hollow slab. To this end, equivalent mass and stiffness of equivalent plate element models corresponding to solid element models of example biaxial hollow slabs were calculated. To verify the efficiency and accuracy of the equivalent plate element models, structural analyses of example structures were performed. Analytical results showed that the natural frequencies of the equivalent plate element models were very close to those of the solid element models. Time history analyses of example biaxial hollow slabs subjected to walking load were conducted using the equivalent plate element models and the solid element models, and the results were compared. It could be seen based on the analytical results that the equivalent plate element model could provide very accurate results compared to the solid element model with significantly reduced analysis time.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.528-533
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• 1995

An analyical method is proposed to construct a clamp jointed structure as an equivalent stiffness matrix element in the finite element modal analysis of a complex beam structure. Static structural analysis was first made for the detail finite element model of the clamp joint. Utilizing the results of this analysis, the equivalent stiffness matrix element was buildup by using the flexibility influence coefficient method and Guyan condensation. The proposed method was applied to finite element modal analysis of a clamp jointed cantilever beam. And the finite element analysis results were compared to those experimental modal analysis. Comparison shows doog agreement each other Furthermore the effects of normal contact(or clamping) load on the equivalent stiffness matrix was also examined. The equivalent stiffness matrix showed little change in spite of the remakable increase in the contact load on the clamp joint.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.17 no.1
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• pp.1-7
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• 2021

This paper presents sensitivity analysis results of strain on notches under cycling loading to 2-D finite element density considering plasticity. Cylindrical notched specimens having some stress concentrations were modeled with 2-D axisymmetrical finite element having various finite element densities. Elasto-plastic finite element analysis was performed for the various finite element models subjected to cycling loading considering plasticity. The finite element analysis results were compared to investigate sensitivity of the finite element analysis variables such as von-Mises effective stress, accumulated equivalent plastic strain, and equivalent plastic strain to 2-D finite element density. As a result of the comparison, it was found that the accumulated equivalent plastic strain is more sensitive than the others whereas the von-Mises effective stress is much less sensitive.

• Structural Engineering and Mechanics
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• v.23 no.6
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• pp.635-649
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• 2006

The static and dynamic responses of guyed telecommunication towers can be determined by using two models, the space truss element model, and the equivalent beam-column element model. The equivalent beam-column analysis is based on the determination of the equivalent shear, torsion, and bending rigidities as well as the equivalent area of the guyed mast. In the literature, two methods are currently available to determine the equivalent properties of lattice structures, namely: the unit load method, and the energy approach. In this study, an equivalent beam-column analysis is introduced based on an equivalent thin plate approach for lattice structures. A finite-element modeling, using suitably modified ABAQUS software, is used to investigate the accuracy of utilizing the different proposed methods in determining the static and dynamic responses of a guyed tower of 364.5-meter high subjected to static and seismic loading conditions. The results from these analyses are compared to those obtained from a finite-element modeling of the actual structure using 3-D truss and beam elements. Good agreement is shown between the different proposed beam-column models, and the model of the actual structure. However, the proposed equivalent thin plate approach is simpler to apply than the other two approaches.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.8
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• pp.449-456
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• 2002

3D Equivalent magnetic Circuit Network Method (EMCNM) is comparatively the easy way that analyzes 3D models of Electric Machine by using permeance as a distributive magnetic circuit parameter under the existing magnetic equivalent circuit method and Numerical Method. The existing 3D EMCNM could not correctly describe the shape of an analysis target when using rectangular shape element or fan shape element, so it made errors when calculating permeance. Therefore, this paper proposes the trapezoidal element contained rectangular element, fan-shape element, and quadrilateral element to express a shape. The proposed method in this research was confirmed as a useful and an accurate method through comparing with the analysis result of SRM model that is sufficiently guaranteed by 2D-Analysis.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.4
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• pp.159-164
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• 2003

In this paper, a three-dimensional finite element method and construction of equivalent-circuit for a linear ultrasonic motor are presented. The validity of three-dimensional finite element routine in this paper is experimentally confirmed by analyzing impedance of a piezoelectric transducer. Using this confirmed finite element routine, impedance and vibration mode of a linear ultrasonic motor are calculated. Elliptical motion of contact point between vibrator and rail of the linear ultrasonic motor is shown for determination of contact points. By using the finite element method and analytic equations, characteristics of the linear ultrasonic motor, such as thrust force, speed, losses, powers and efficiency, are calculated. The results are confirmed by experiment. Finally, equivalent circuit parameters of the linear ultrasonic motor are obtained using the three-dimensional finite element method and analytic equations.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.375-380
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• 2007

The goal of this paper is to develop a rational static method which consider efficiently the dynamic effect of the gravity load following sudden removal of element. For this goal this paper introduce the equivalent load for element stiffness which is a preceding research result and will develop equivalent static analysis which will be able to predict the maximum behavior considering dynamic effect. Some examples are provided to verify it. Equivalent static analysis is compared with the analysis method which is recommended by the GSA2003 guidelines and the time-history analysis which is the most accurate for dynamic behavior.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.10a
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• pp.161-168
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• 1995

The variable-node solid element with rotational degrees of freedom has been developed far efficient connection of transition zones and far connection of different types of elements with rotational degrees of freedom. In applying this new element to engineering problems, it is necessary to fine the relations between tractions and equivalent nodal farces. In this case, the equivalent forces in solid element with rotational degrees of freedom and ratational forces are a bit different from that af conventional solid elements. Some typical examples are presented.

• Structural Engineering and Mechanics
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• v.46 no.2
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• pp.213-229
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• 2013

Although performance based assessment procedures are mainly developed for reinforced concrete and steel buildings, URM (Unreinforced Masonry) buildings occupy significant portion of buildings in earthquake prone areas of the world as well as in IRAN. Variability of material properties, non-engineered nature of the construction and difficulties in structural analysis of masonry walls make analysis of URM buildings challenging. Despite sophisticated finite element models satisfy the modeling requirements, extensive experimental data for definition of material behavior and high computational resources are needed. Recently, nonlinear equivalent frame models which are developed assigning lumped plastic hinges to isotropic and homogenous equivalent frame elements are used for nonlinear modeling of URM buildings. The equivalent frame models are not novel for the analysis of masonry structures, but the actual potentialities have not yet been completely studied, particularly for non-linear applications. In the present paper an effective tool for the non-linear static analysis of 2D masonry walls is presented. The work presented in this study is about performance assessment of unreinforced brick masonry buildings through nonlinear equivalent frame modeling technique. Reliability of the proposed models is tested with a reversed cyclic experiment conducted on a full scale, two-story URM building at the University of Pavia. The pushover curves were found to provide good agreement with the experimental backbone curves. Furthermore, the results of analysis show that EFM (Equivalent Frame Model) with Dolce RO (rigid offset zone) and shell element have good agreement with finite element software and experimental results.