• Wind and Structures
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• 제10권6호
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• pp.533-542
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• 2007

The cable-stayed-suspension hybrid bridge is a cooperative system of the cable-stayed bridge and suspension bridge, and takes some advantages and also makes up some deficiencies of both the two bridge systems, and therefore becomes strong in spanning. By taking the cable-stayed-suspension hybrid bridge, suspension bridge and cable-stayed bridge with main span of 1400 m as examples, the mechanics performance including the static and dynamic characteristics, the aerostatic and aerodynamic stability etc is investigated by 3D nonlinear analysis. The results show that as compared to the suspension bridge and cable-stayed bridge, the cable-stayed-suspension hybrid bridge has greater structural stiffness, less internal forces and better wind stability, and is favorable to be used in super long-span bridges.

• Structural Engineering and Mechanics
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• 제66권5호
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• pp.665-676
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• 2018

In this study, a four-node quadrilateral partial mixed plate element with low degrees of freedom (dofs) is developed for static and free vibration analysis of functionally graded material (FGM) plates rested on Winkler-Pasternak elastic foundations. The formulation of the presented finite element model is based on a parametrized mixed variational principle which is developed recently by the first author. The presented finite element model considers the effects of shear deformations and normal flexibility of the FGM plates without using any shear correction factor. It also fulfills the boundary conditions of the transverse shear and normal stresses on the top and bottom surfaces of the plate. Beside these capabilities, the number of unknown field variables of the plate is only six. The presented partial mixed finite element model has been validated through comparison with the results of the three-dimensional (3D) theory of elasticity and the results obtained from the classical and high-order plate theories available in the open literature.

• 한국기계가공학회지
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• 제10권1호
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• pp.16-22
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• 2011

Recently, the deburring process which is last process of manufacture is one of the important process for complete product. The development of shape guided automatic deburring machine is essential because manual deburring process has very irregular quality and higher error rate as well as consider irregular shape radius. In order to develop of shape guided automatic deburring machine, in this study, we conducted 3D design, assembly, machine simulation and structural analysis using CATIA. Also, we conducted to make automatic deburring machine and conducted a performance test.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1991년도 춘계학술대회논문집; 한국해사기술연구소, 대전; 1 Jun. 1991
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• pp.31-39
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• 1991

When predicting shipboard noise levels, the accuracy depends largely on the value of the structureborne noise transmission loss. Although empirical formulars are frequently used because of their simplicities, researches on the analytical methods to estimate the transmission loss of structureborne noise such as wave guide theory and SEA has long been one of the major topics in shipboard acoustics to overcome the inherent limitations of empirical ones. This paper describes an application of SEA to predict the transmission loss of the structurebornenoise of a simple ship-like structural model consisted of 22 flat plates. The result shows that discrepancies between experimental and theoretical transmission losses are less than 3 dB.

• Structural Engineering and Mechanics
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• 제45권1호
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• pp.33-52
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• 2013

In this study, the effects of crack depth and crack location on the in-plane free vibration of cracked frame structures have been investigated numerically by using the Finite Element Method. For the rectangular cross-section beam, a crack element is developed by using the principles of fracture mechanics. The effects of crack depth and location on the natural frequency of multi-bay and multi-store frame structures are presented in 3D graphs. The comparison between the present work and the results obtained from ANSYS shows a very good agreement.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2012년도 춘계학술논문집 2부
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• pp.617-619
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• 2012

본 논문에서는 알루미늄 폼 복합재료로 된 DCB(이중외팔보) 구조체의 파괴 거동을 시뮬레이션 해석하였다. 시뮬레이션 해석에 사용된 모델은 영국 공업규격과 ISO국제규격에 의거하여 3D모델을 설계하였다. 해석 결과 모델의 두께가 두꺼울수록 발생한 크랙의 길이가 길게 나타났고, 높은 하중이 발생하였다. 이와 같은 연구에서 얻어진 해석 결과를 통하여 알루미늄 폼 재질로 접합된 실제 복합재 구조물에 적용시켜 파괴거동을 분석하고 그 기계적인 특성을 파악할 수 있다.

• 한국철도학회논문집
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• 제9권2호
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• pp.222-229
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• 2006

Recently, the development of the paved track is required as a low-maintenance of conventional line. The main reason is that the line capacity and bearing of track are increased progressively. The important factors of paved track are stability and applicability. To be based on this subject, Cement Mortar Pouring(CMP) paved track is developed. CMP paved track is a kind of ballast reinforced track using the prepacked concrete technique. The most important thing to design the paved track is to optimize the track structure considering various conditions. Because construction environment is very limited, cost is expensive and it has very complicated behavior. On this paper, structural characteristics of the paved track are investigated using the 3D finite element analysis to verify the optimized structure of the CMP track.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1627-1632
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• 2000

Recently, piezoelectric materials have attracted considerable attention because of its self-sensing and actuating properties. To model smart structures, numerical modeling of structures with piezoelectric devices is essential. As many factors affect the performance of smart structures, optimization of these parameters is necessary. In this paper, the shape design sensitivity analysis of the 3D piezoelectric and structural elements is developed and shape optimization is performed. For the evaluation of the sensitivity, the finite element method is used. For the shape sensitivity, the domain velocity field is calculated. An acoustic cavity model is presented as a numerical example to study the feasibility of the formulation. The continuum sensitivity is compared with the results of the finite difference method by ANSYS. And the sequential linear programming (SLP) algorithm is used as the optimization algorithm.

• Computers and Concrete
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• 제12권4호
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• pp.519-536
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• 2013

This paper presents a mixed formulation frame element with the assumptions of the Timoshenko shear beam theory for displacement field and that accounts for interaction between shear and normal stress at material level. Nonlinear response of the element is obtained by integration of section response, which in turn is obtained by integration of material response. Satisfaction of transverse equilibrium equations at section includes the interaction between concrete and transverse reinforcing steel. A 3d plastic damage model is implemented to describe the hysteretic behavior of concrete. Comparisons with available experimental data on RC structural walls confirm the accuracy of proposed method.

• Computers and Concrete
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• 제12권4호
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• pp.443-498
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• 2013

A detailed finite element modeling is presented for the simulation of the nonlinear behavior of reinforced concrete structures which manages to predict the nonlinear behavior of four different experimental setups with computational efficiency, robustness and accuracy. The proposed modeling method uses 8-node hexahedral isoparametric elements for the discretization of concrete. Steel rebars may have any orientation inside the solid concrete elements allowing the simulation of longitudinal as well as transverse reinforcement. Concrete cracking is treated with the smeared crack approach, while steel reinforcement is modeled with the natural beam-column flexibility-based element that takes into consideration shear and bending stiffness. The performance of the proposed modeling is demonstrated by comparing the numerical predictions with existing experimental and numerical results in the literature as well as with those of a commercial code. The results show that the proposed refined simulation predicts accurately the nonlinear inelastic behavior of reinforced concrete structures achieving numerical robustness and computational efficiency.