• Journal of Mechanical Science and Technology
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• v.15 no.11
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• pp.1499-1506
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• 2001

Various transition elements are used in general for the effective finite element analysis of complicated mechanical structures. In this paper, a solid-to-beam transition finite element, which can b e used for connecting a C1-continuity beam element to a continuum solid element, is proposed. The shape functions of the transition finite element are derived to meet the compatibility condition, and a transition element equation is formulated by the conventional finite element procedure. In order to show the effectiveness and convergence characteristics of the proposed transition element, numerical tests are performed for various examples. As a result of this study, following conclusions are obtained. (1) The proposed transition element, which meets the compatibility of the primary variables, exhibits excellent accuracy. (2) In case of using the proposed transition element, the number of nodes in the finite element model may be considerably reduced and the model construction becomes more convenient. (3) This formulation method can be applied to the usage of higher order elements.

• Computational Structural Engineering
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• v.8 no.2
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• pp.85-93
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• 1995

This study presents the formulation of beam transition elements and transition zone elements for the effective finite element analysis of the transition regions of coupled wall structures. Beam transition element can be described as the quasi beam element which is replaced by an equivalent plane stress element, keeping equally, the basic behavior of beam element, based on the kinematic and force constraints between beam and wall element. These beam transition elements solve the incompatibility related to different degrees of freedom between beam and wall element in transition regions. Also, the stiffness matrices of transition zone elements which are directly connected with beam transition elements in transition regions can be derived from the equivalent constraint conditions. These elements provide the reasonable mesh grading schemes for transition regions and can be usefully applied to the transition regions of all structures that the interactions of wall and beam element are considered.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.351-356
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• 2000

Various transition elements are generally used for the effective analysis of a complicated mechanical structure. In this paper, a solid-to-beam transition finite element which connects a continuum element and a $c^1-continuity$ beam element each other is proposed. The shape functions of the transition finite elements, which a 8-noded hexahedral solid element fur 3D analysis and a 4-noded quadrilateral plane element fur 2D analysis are connected to a Euler's beam element, are explicitely formulated. In order to show the effectiveness and convergence characteristics of the proposed transition elements. numerical tests are performed for various examples and their results are compared with those obtained by other methods. As the result of this study. following conclusions are obtained: (1)The proposed transition finite elements show the monotonic convergence characteristics because of having used the compatible displacement folds. (2)As being used the transition element in the finite element analysis, the finite element modelings are more convenient and the analysis results are more accurate because of the formulation characteristies of the Euler's beam element.

• Structural Engineering and Mechanics
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• v.39 no.3
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• pp.339-360
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• 2011

In the h-type adaptive analysis, when an element is refined or subdivided, new nodes are added. Among them are the transition nodes which are the corner nodes of the new elements formed by subdivision and, simultaneously, the mid-side nodes of the adjacent non-subdivided elements. To secure displacement compatibility, the slave-node approach in which the DOFs of a transition node are constrained by those of the adjacent nodes had been used. Alternatively, transition elements which possess the transition nodes as active mid-side/-face nodes can be used. For C0 plate analyses, the conventional slave-node constraints and the previously derived ANS transition elements are implemented. In both implementations, the four-node element is the ANS element. With reference to the predictions of the transition elements, the slave-node approach not only delivers erroneous results but also fails the patch test. In this paper, the patch test failure is resolved by developing a set of new constraints with which the slave-node approach surpasses the transition-element approach. The accuracy of the slave-node approach is further improved by developing a hybrid four-node element in which the assumed moment and shear force modes are in strict equilibrium.

• Structural Engineering and Mechanics
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• v.1 no.1
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• pp.61-74
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• 1993

A new three-dimensional transition solid element was presented for the automated three-dimensional adaptive h-refinement or the local mesh refinement where the steep stress gradient exists. The proposed transition element was established by adding variable nodes(element nodes) to basic 8-node for an effective connection between the refined region and the coarse region with minimum degrees of freedom possible. To be consistent in accuracy with 8-node solid element with nonconforming modes, this transition element was also improved through the addition of the modified nonconforming modes. Numerical examples show that the performance of the element and the applicability to 3D adaptations are satisfactory.

• Journal of electromagnetic engineering and science
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• v.17 no.1
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• pp.29-33
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• 2017

This paper proposes a half-mode substrate integrated waveguide (HMSIW) amplifier using lumped-element transition. The input and output impedances of this amplifier are matched by the lumped-element transition structure. This structure provides compact impedance and mode matching circuits between the HMSIW and a stand-alone amplifier. Surface mount technology inductors and capacitors are implemented to realize the lumped-element transition. A prototype of the proposed HMSIW amplifier shows 15 dB gain with 3 dB bandwidth of 4 to 7.05 GHz in a simulation and measurement.

• Structural Engineering and Mechanics
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• v.3 no.1
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• pp.75-89
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• 1995

A transition membrane element designated as CLM which has variable mid-side nodes with drilling freedoms has been presented in this paper. The functional for the linear problem, in which the drilling rotations are introduced as independent variables, has been formulated. The transition elements with variable side nodes can be efficiently used in the local mesh refinement for the in-plane structures, which have stress concentrations. A modified Gaussian quadrature is needed to be adopted to evaluate the stiffness matrices of these transition elements mainly due to the slope discontinuity of displacement within the elements. Detailed numerical studies show the excellent performance of the new transition elements developed in this study.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.04a
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• pp.9-16
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• 1995

A new three-dimensional transition solid element with drilling degrees of freedom is presented. The proposed transition element is established by adding variable nodes to a basic 8-node element for an effective connection between the refined region and the coarse. The derivation of the element in this paper is based on the variational principles in which the drilling rotations are introduced as independent variables. This element was also improved through the addition of modified non-conforming modes. Numerical examples show that performance of the element and the applicability to 3D adaptations are satisfactory.

• Steel and Composite Structures
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• v.43 no.3
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• pp.363-373
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• 2022

As a key reinforcement connection between a tower and a substructure in offshore wind turbine system, the transition piece is inevitably subjected to cyclic dynamic environmental loads such as wind, current and wave. Therefore, well designed transition piece with high strength and good fatigue resistance is of great significance to the structural safety and reliability of offshore wind power systems. In this study, the structural behavior of the transition piece was studied by an extensive sets of finite element analyses. Three widely used types of transition piece were considered. The characteristics of stress development, fatigue life and weight depending on the type of the transition piece were investigated in the ultimate limit state (ULS) and the fatigue limit state (FLS) of a 5-MW offshore wind turbine to be placed in Korea. An optimal form of the transition piece was proposed based on this parametric study.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05a
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• pp.77-82
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• 1997

The CANDU-6 transition core refuelled from 37-element fuel to CANFLEX-NU fuel has been evaluated by an 100full power day time-dependent fuel-management simulation to find the core compatibility with the CANFLEX fuel loading. The simulation calculations for the transition core were carried out with the RFSP code, provided by the cell averaged fuel properties obtained from the POWDERPUFS-V code. The simulation results were compared with those of the current 37-element fuel loading only. The results show that the CANFLEX-NU fuel bundles will be compatible with the CANDU-6 reactor because the core physics characteristics of CANFLEX-NU fuel are very similar to those of the 37-element fuel bundle.