• Structural Engineering and Mechanics
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• 제16권3호
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• pp.361-369
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• 2003

In this paper, the structural behavior of R/C cylindrical panel is analyzed by experimental results. To avoid the geometric imperfection, R/C shell specimens are made by use of a stiff steel mold. From experimental results, the load carrying behavior of R/C cylindrical panel is presented under an external lateral pressure. Even if R/C shell does not posses geometric imperfections, the inaccuracy of the reinforcement position strongly affects to the ultimate strength and the failure patterns of such shells. To explain these effects, FEM nonlinear analyses are done under the same conditions as those of experiments. The behavior of R/C cylindrical shells are well simulated under the consideration of both the geometric imperfection and several inaccuracies.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 봄 학술발표회논문집
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• pp.133-140
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• 2000

The objective of this study is to develop a damage model based on damage mechanics that can be used to analyze the mechanical behavior of structures with defects and the global behavior of damaged structures. A modified second order damage tensor that can be applied to finite element analysis is used to reflect the effect of damage. The damage stress computed from the effective stress is considered as an additional loading term acting on nodes and can represent the effect of crack surface. The accuracy of the proposed algorithm is verified by comparing the analysis results with the experimental data from other studies and the analysis results based on transverse isotropic theory. The developed damage model is applied to the analyses of structures with cracks under linear elastic condition. Numerical results show that the developed model can effectively analyze the global behavior of damaged structures.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.374-379
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• 2008

The purpose of seismic isolation system among them is to lengthen the period of structure and make its period shift from the dominant period of earthquake. In this study, the seismic behavior of arch structure with lead rubber bearing(LRB) and friction pendulum system(FPS) is analyzed. The arch structure is the simplest structure and has the basic dynamic characteristics among large spatial structures. Also, Large spatial structures have large vertical response by horizontal seismic vibration, unlike seismic behavior of normal rahmen structures. When horizontal seismic load is applied to the large spatial structure with isolation systems, the horizontal acceleration response of the large spatial structure is reduced and the vertical seismic response is remarkably reduced.

• Geomechanics and Engineering
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• 제14권6호
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• pp.601-614
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• 2018

This study presents structural and parametric analyses on the behavior of an integrated and pile-bent abutment with mechanically stabilized earth wall (IPM) bridge. The IPM bridge is an integral abutment bridge (IAB) with partially protruded piles, which excludes earth pressure by means of a mechanically stabilized earth wall developed by the authors. The results of the analysis indicate that the IPM bridge, as any other IAB, is influenced to a large extent by temperature and time-dependent loads. When these loads are applied, the stress on a pile in the IPM bridge decreases as the displacement of the pile top increases, because the piles protrude from the ground surface and no soil reaction is generated on the protruded pile. Because the length of an IAB is restricted by the forces acting on its piles, the IPM bridge is an effective alternative to extend its length.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 춘계학술대회 논문집
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• pp.186-189
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• 2004

Although magnesium has high potential for structural material due to the lightweight and high specific strength, the structural application has been limited by the low ductility at room temperature. The reason of the poor ductility is few activated slip systems of magnesium (HCP structure) during deformation. As temperature increases, however, additional non-basal slip systems are incorporated to exhibit higher ductility comparable to aluminum. In the present study, a series of tensile tests of Mg-Al alloy has been carried out to study deformation behavior with temperature variation. Analysis of load relaxation test results based on internal variable approach gave information about relationship between the micromechanical character and corresponding deformation behavior of magnesium. Especially, the material parameter, p representing dislocation permeability through barriers was altered from 0.1 to 0.15 as the non-basal slip systems were activated at high temperature.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1992년도 봄 학술발표회 논문집
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• pp.65-70
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• 1992

This study deals with the finite element analysis of the monotonic behavior of reinforced concrete beams and beam-column joint subassemblages. It is assumed that the behavior of these members can be discribed by a plane stress field. Concrete and reinforcing steel are represented by separate material models which are combined together with a model of the interaction between reinforcing bar and concrete through bond-slip to discribe the behavior of the composite reinforced concrete material. To discribe the concrete behavior, a nonlinear orthotropic model is adopted and the crack is discribed by a system of orthogonal cracks, which are rotating as the principal strain directions are changed. A smeared finite element model based on the fracture mechanics principles are used to overcome the numerical defect according to the finite element mesh size. Finally, correlation studies between analytical and experimental results and several parameter studies are conducted with the objective to estabilish the validity of the proposed model and identify the significance of various effects on the local and global response of reinforced concrete members.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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• pp.323-328
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• 1995

This paper is experimental study to define the structural behaviors of reinforced flat plate under combined gravity and lateral loads. Specific objectives of this study reported herein are : (1) To study the behavior of a typical slab-column subassemblage under lateral loading. (2) To study the effects of vertical loads on slab-column lateral load behavior. (3) To investigate the post-failure behavior of slab-column connetios. To achieve these objectives, this study includes four tests of slab-column subassemblages that were made for 1/2 scale. Finally, Test results of this study show that the level of gravity load on the flat plate is one of the most important factors determining the lateral behavior of flat plate connections.

• Structural Engineering and Mechanics
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• 제58권6호
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• pp.1109-1126
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• 2016

The present paper focuses on size optimization of double layer barrel vaults considering nonlinear behavior. In order to tackle the optimization problem an improved colliding bodies optimization (ICBO) algorithm is proposed. The important task that should be achieved before optimization of structural systems is to determine the best form having the least cost. In this study, an attempt is done to find the best form then it is optimized considering linear and non-linear behaviors. In the optimization process based on nonlinear behavior, the geometrical and material nonlinearity effects are included. A large-scale double layer barrel vault is presented as the numerical example of this study and the obtained results indicate that the proposed ICBO has better computational performance compared with other algorithms.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 봄 학술발표회 논문집
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• pp.167-174
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• 2003

It is absolutely natural to be interested in durability and safety of the structure under shear behavior. To fulfill this desire, a comparison on the shear behavior between steel fiber reinforced concrete both simple and continuous beams is done to use in the field working. Several operations are conducted : First of all, plan for optimal combination is standardized. Second, resistance for shear has been generalized in that it is decided by combination of individual elements. Third, as the fracture of tensile bar leads to destruction of specimen, shear behavior of whole specimen is decided by stress working on tensile bar. It should be generalized for other specimens also. Forth, evidence of the softness of steel fiber reinforced concrete beam by experiment lead to application in the fields. Finally, numeral values of the steel fiber reinforced concrete are analyzed and the result is compared to those of experiments. With these consequences, this study was done for the application to dynamic structures such as bridges and the repair and rehabilitation.

• Structural Engineering and Mechanics
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• 제59권3호
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• pp.475-502
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• 2016

Nanobeams are widely used as a structural element for nanodevices and nanomachines. The development of nano-sized machines depends on proper understanding of mechanical behavior of these nano-sized beam elements. Small length scales such as lattice spacing between atoms, surface properties, grain size etc. are need to be considered when applying any classical continuum model. In this study, Eringen's nonlocal elasticity theory is incorporated into classical beam model considering the effects of axial extension and the shear deformation to capture unique static behavior of the nanobeams under continuum mechanics theory. The governing differential equations are obtained for curved beams and solved exactly by using the initial value method. Circular uniform beam with concentrated loads are considered. The displacements, slopes and the stress resultants are obtained analytically. A detailed parametric study is conducted to examine the effect of the nonlocal parameter, mechanical loadings, opening angle, boundary conditions, and slenderness ratio on the static behavior of the nanobeam.