• Journal of Korean Association for Spatial Structures
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• v.19 no.2
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• pp.51-61
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• 2019

The objective of this study is to analysis the seismic response of 200m spanned honeycomb lattice domes under horizontal and up-down ground motion of El Centro earthquake. For the analysis of seismic response of the honeycomb lattice domes by rise/span ratio, the time history analysis is used for the estimation of the dynamic response. The low rise lattice dome is less deformed and less stressed than the high rise lattice dome for the earthquake ground motion. The 3-dimensional earthquake response is not significantly different the dynamic response of one directional ground motion. The earthquake response of domes with LRB isolation system is significantly reduced for the asymmetric vertical deformation and the horizontal and vertical accelerations.

• Steel and Composite Structures
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• v.21 no.1
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• pp.217-247
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• 2016

Five extended cylindrical reticulated shells are proposed by changing distribution rule of diagonal rods based on three fundamental types. Modeling programs for fundamental types and extended types of cylindrical reticulated shell are compiled by using the ANSYS Parametric Design Language (APDL). On this basis, conditional formulas are derived when the grid shape of cylindrical reticulated shells is equilateral triangle. Internal force analysis of cylindrical reticulated shells is carried out. The variation and distribution regularities of maximum displacement and stress are studied. A shape optimization program is proposed by adopting the sequence two-stage algorithm (RDQA) in FORTRAN environment based on the characteristics of cylindrical reticulated shells and the ideas of discrete variable optimization design. Shape optimization is achieved by considering the objective function of the minimum total steel consumption, global and locality constraints. The shape optimization for three fundamental types and five extended types is calculated with the span of 30 m~80 m and rise-span ratio of 1/7~1/3. The variations of the total steel consumption along with the span and rise-span ratio are analyzed with contrast to the results of shape optimization. The optimal combination of main design parameters for five extended cylindrical reticulated shells is investigated. The total steel consumption affected by distribution rule of diagonal rods is discussed. The results show that: (1) Parametric modeling method is simple, efficient and practical, which can quickly generate different types of cylindrical reticulated shells. (2) The mechanical properties of five extended cylindrical reticulated shells are better than their fundamental types. (3) The total steel consumption of cylindrical reticulated shells is optimized to be the least when rise-span ratio is 1/6. (4) The extended type of three-way grid cylindrical reticulated shell should be preferentially adopted in practical engineering. (5) The grid shape of reticulated shells should be designed to equilateral triangle as much as possible because of its reasonable stress and the lowest total steel consumption.

• Journal of Korean Association for Spatial Structures
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• v.20 no.2
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• pp.69-76
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• 2020

Wind tunnel tests were conducted to analyze the wind fluctuating pressures on a circular closed and open dome roof with a low span rise. Two dome models with various geometric parameters (height/span ratios and open ratios) were used for fixed span rise ratio dome and wind pressure spectrum were analyzed. The applicability was examined in comparison with the spectral model proposed in the previous studies. The analysis results show that the wind pressure spectrum of open dome roof tends to increase power in the high frequency range and the second peak is found in the area different from the closed dome roof. In addition, according to the comparison analysis with the previous proposed spectral model, it was found that it is not applicable to the closed and open dome roofs with low rise ratio due to the different peak frequencies.

• Structural Engineering and Mechanics
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• v.56 no.5
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• pp.813-833
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• 2015

Spherical reticulated shells are widely applied in structural engineering due to their good bearing capability and attractive appearance. Parametric modeling of spherical reticulated shells is the basis of internal analysis and optimization design. In the present study, generation methods of nodes and the corresponding connection methods of rod elements are proposed. Modeling programs are compiled by adopting the ANSYS Parametric Design Language (APDL). A shape optimization method based on the two-stage algorithm is presented, and the corresponding optimization program is compiled in FORTRAN environment. Shape optimization is carried out based on the objective function of the minimum total steel consumption and the restriction condition of strength, stiffness, slenderness ratio, stability. The shape optimization of four typical Schwedler spherical reticulated shells is calculated with the span of 30 m~80 m and rise to span ratio of 1/7~1/2. Compared with the shape optimization results, the variation rules of total steel consumption along with the span and rise to span ratio are discussed. The results show that: (1) The left and right rod-Schwedler spherical reticulated shell is the most optimized and should be preferentially adopted in structural engineering. (2) The left diagonal rod-Schwedler spherical reticulated shell is second only to left and right rod regarding the mechanical behavior and optimized results. It can be applied to medium and small-span structures. (3) Double slash rod-Schwedler spherical reticulated shell is advantageous in mechanical behavior but with the largest total weight. Thus, this type can be used in large-span structures as far as possible. (4) The mechanical performance of no latitudinal rod-Schwedler spherical reticulated shell is the worst and with the second largest weight. Thus, this spherical reticulated shell should not be adopted generally in engineering.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.04a
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• pp.151-158
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• 1999

The single layer latticed domes have various behaviors with each geometrical shape and scale, and they are affected by vertical component as well as horizontal component of the dynamic load. And they represent very different earthquake responses under each ground acceleration compared with another structural systems. Generally, all of the members of latticed domes undergo three dimensional deflections if they are subjected to arbitrary one dimensional horizontal load under earthquake motions. And their response characteristics are very different to their shapes, rise/span ratios, and damping mechanisms. In this study the .earthquake response behavior is verified according to the factor of each shape, rise/span ratio, ana damping ratio of latticed domes, which undergo horizontal and vertical earthquake motions by numerical approaches.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.489-496
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• 1998

The single layer latticed domes have various behaviors with each geometrical shape and scale, and they are affected by vertical component as well as horizontal component of the dynamic load. And they represent ye different earthquake responses under each ground acceleration compared with another structural systems. Generally, all of the members of latticed domes undergo three dimensional deflections if they are subjected to arbitrary one dimensional horizontal load under earthquake motions. And their response characteristics are very different to their shapes, rise/span ratios, and damping mechanisms. In this study, the earthquake response behavior is verified according to the factor of each shape, rise/span ratio, and damping ratio of latticed domes, which undergo horizontal and vertical earthquake motions by numerical approaches.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.4
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• pp.175-183
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• 2004

The most important element is a rise ratio when regarding beauty and economics of arch bridges. Only the effect of dead load has been considered to decide the rise ratio. In this study, when going over the rise ratio of arch bridges, examined the problems, that the determination of the rise ratio by the dead load has, by adding the factor of a determination of optimum rise ratio, which is not only the effect of the dead load that has been currently considered but also the problem with respect to dynamic stability that is now taken seriously. Synthetically, when deciding rise ratio that is investigated in basic step of design, it is necessary to consider the evaluation dynamic stability.

• International Journal of High-Rise Buildings
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• v.3 no.1
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• pp.1-8
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• 2014

When seismic isolation system is applied to high aspect-ratio (height/wide-ratio) steel structures, there are several problems to be taken into consideration. One is lifting up tensile force on the isolation bearing by overturning moment caused by earthquake. Another is securing building stiffness to produce seismic isolation effects. Under these conditions, this paper reports the structural design of high-rise research building in the campus of Tokyo Institute of Technology. With the stepping-up system for the corner bearings, the narrow sides of single span framework are designed to concentrate the dead load as counter-weight for the tensile reaction under earthquake. Also we adopted concrete in-filled steel column and Mega-Bracing system covering four layers on north & south framework to secure the horizontal stiffness of the building.

• Structural Engineering and Mechanics
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• v.37 no.1
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• pp.39-59
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• 2011

Results of an experimental investigation on the behavior and ultimate shear capacity of 27 reinforced concrete Transfer (deep) beams are summarized. The main variables were percent longitudinal(tension) steel (0.28 to 0.60%), percent horizontal web steel (0.60 to 2.40%), percent vertical steel (0.50to 2.25%), percent orthogonal web steel, shear span-to-depth ratio (1.10 to 3.20) and cube concrete compressive strength (32 MPa to 48 MPa).The span of the beam has been kept constant at 1000 mm with100 mm overhang on either side of the supports. The result of this study shows that the load transfer capacity of transfer (deep) beam with distributed longitudinal reinforcement is increased significantly. Also, the vertical shear reinforcement is more effective than the horizontal reinforcement in increasing the shear capacity as well as to transform the brittle mode of failure in to the ductile mode of failure. It has been observed that the orthogonal web reinforcement is highly influencing parameter to generate the shear capacity of transfer beams as well as its failure modes. Moreover, the results from the experiments have been processed suitably and presented an analytical model for design of transfer beams in high-rise buildings for estimating the shear capacity of beams.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.1 s.16
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• pp.55-62
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• 2005

Parabolic arch ribs are widely used in practical. In case of circular arch ribs. Inelastic in-plane buckling behaviors were investigated by Trahair(1996). Recently Yong-lin Pi & Bradford(2004) investigated about in-plane design equation for circular arch ribs. In $1970{\sim}1980$. In-plane buckling strength about parabolic arch ribs were studied by some japan researchers (Sinke, Kuranishi). Study results of Sinke & kuranishi are only valid for rise-span ratio $0.1{\sim}0.2$. In this paper. The researchers investigated about in-plane inelastic buckling behaviors of parabolic arch ribs having rise-span ratio from 0.1 to 0.4. From the results. When the rise-span ratio increase, flexural moments increase and influence of axial force to in-plane buckling strength decrease. Finally, buckling curves for parabolic arch ribs subjected distributed loading along the axis were suggested.