• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.204-209
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• 2000

This paper suggests that post-tensioned and dome-shaped space truss formed by post-tersionong is easy to fabricate in construction process. In particular, a laboratory model is used to show how a flat space truss system can be transformed into a dome-shaped space truss by means of post-tensioning. There are some diserpancy in vertical displacement of the dxperiment and theoretical analysis for space truss. Nonlinear analysis is used to predict the final shape shape of the space truss, the experiments tndicates that this construction method can offer economy over traditional methods. In addition, the analysis indicates that when all the sxisting mechanisms are controlled, the nonlinear finite element method is more reliable way to predict the shape of the dome-shaped space truss than the linear analysis.

• Wind and Structures
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• 제17권3호
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• pp.317-343
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• 2013

When evaluating flutter instability, it is often assumed that incident wind is normal to the longitudinal axis of a bridge and the flutter critical wind speed estimated from this direction is most unfavorable. However, the results obtained in this study via oblique sectional model tests of four typical types of bridge decks show that the lowest flutter critical wind speeds often occur in the yaw wind cases. The four types of bridge decks tested include a flat single-box deck, a flat ${\Pi}$-shaped thin-wall deck, a flat twin side-girder deck, and a truss-stiffened deck with and without a narrow central gap. The yaw wind effect could reduce the critical wind speed by about 6%, 2%, 8%, 7%, respectively, for the above four types of decks within a wind inclination angle range between $-3^{\circ}$ and $3^{\circ}$, and the yaw wind angles corresponding to the minimal critical wind speeds are between $4^{\circ}$ and $15^{\circ}$. It was also found that the flutter critical wind speed varies in an undulate manner with the increase of yaw angle, and the variation pattern is largely dependent on both deck shape and wind inclination angle. Therefore, the cosine rule based on the mean wind decomposition is generally inapplicable to the estimation of flutter critical wind speed of long-span bridges under skew winds. The unfavorable effect of yaw wind on the flutter instability of long-span bridges should be taken into consideration seriously in the future practice, especially for supper-long span bridges in strong wind regions.

• Journal of the Korean Wood Science and Technology
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• 제42권6호
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• pp.708-713
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• 2014

트러스는 북미 지역이나 호주, 뉴질랜드 등 목조주택이 일반화된 지역에 주택을 시공함에 있어 주로 사용되는 구조부재로써, 공장에서 제작되며 현장에서 제작하기는 힘들다. 반면에, 목조주택규모가 작은 국내에서는 제작비, 운반비, 경험부족 등을 이유로 트러스의 사용이 매우 제한적이며 대부분의 현장에서 서까래 공법으로 시공을 하고 있는 실정이다. 본 연구에서는 일반적으로 사용되는 금속제 트러스 플레이트가 아닌 현장에 버려지는 OSB를 덧댐판(gusset)으로 사용하여 현장에서 간단하게 제작이 가능한 형태의 경사트러스와 수평트러스를 제작해 보고 그 휨강도를 측정해 봄으로써 소규모 단독주택이 대부분인 목조주택 현장에서 사용가능 여부를 평가하고자 하였다. 경사트러스의 허용하중을 실제하중과 비교하였을 때, 지간거리 6 m에서 지붕경사트러스의 허용하중 및 실제하중은 10.60 kN 및 5.26 kN로 나타내어 사용하기에 충분하다고 판단된다. 지간거리 6 m의 수평트러스를 바닥장선으로 사용할 경우, 허용하중 및 실제하중은 7.18 kN 및 7.43 kN로 나타나 허용하중이 약간 낮기는 하지만 그 차이가 크지 않으므로 구조보강 및 부재의 변경 등을 통하여 사용이 가능한 것으로 판단된다.

• 한국공간구조학회지
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• 제12권2호
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• pp.13-17
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• 2012

• Ocean Systems Engineering
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• 제9권4호
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• pp.423-448
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• 2019

Very Large Floating Structures (VLFS) are one among the solution to pursue an environmentally friendly and sustainable technology in birthing land from the sea. VLFS are extra-large in size and mostly extra-long in span. VLFS may be classified into two broad categories, namely the pontoon type and semi-submersible type. The pontoon-type VLFS is a flat box structure floating on the sea surface and suitable in regions with lower sea state. The semi-submersible VLFS has a deck raised above the sea level and supported by columns which are connected to submerged pontoons and are subjected to less wave forces. These structures are very flexible compared to other kinds of offshore structures, and its elastic deformations are more important than their rigid body motions. This paper presents hydroelastic analysis carried out on an innovative VLFS called truss pontoon Mobile Offshore Base (MOB) platform concept proposed by Srinivasan and Sundaravadivelu (2013). The truss pontoon MOB is modelled and hydroelastic analysis is carried out using HYDRAN-XR^* for regular 0° waves heading angle. Results are presented for variation of added mass and damping coefficients, diffraction and wave excitation forces, RAOs for translational, rotation and deformational modes and vertical displacement at salient sections with respect to wave periods.

• 한국공간구조학회논문집
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• 제20권1호
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• pp.61-67
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• 2020

In the era of the Fourth Industrial Revolution, Various attempts are being made to converge new industries with IT industry to find new growth engines in the field of IT, maximizing efficiency in terms of productivity. 3D printers are also related to this, and various studies have been conducted worldwide to utilize them in the construction industry. At present, there is an active effort to study atypical structures using 3D printers. The most widely used method is the use of glass panels, however, the additional cost of the manufacturing process and thus the overall project cost cannot be ignored. In addition, the construction of the curvature of the existing two-way curved surface in the conventional flat joint method is not suitable for implementing an amorphous shape. In this paper, we propose an optimized shape through Abaqus analysis of various shapes of Space Truss interior using 3D printing technology using polymer.

• Advances in concrete construction
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• 제14권3호
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• pp.195-204
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• 2022

As a brittle failure mode, punching-shear failure can be widely found in traditional RC slab-column connections, which may lead to the entire collapse of a flat plate structure. In this paper, a novel RC slab-column connection with inner steel truss was proposed to enhance the punching strength. In the proposed connection, steel trusses, each of which was composed of four steel angles and a series of steel strips, were pre-assembled at the periphery of the column capital and behaved as transverse reinforcements. With the aim of exploring the punching behavior of this novel RC slab-column connection, a static punching test was conducted on two full-scaled RC slab specimens, and the crack patterns, failure modes, load-deflection and load-strain responses were thoroughly analyzed to explore the contribution of the applied inner steel trusses to the overall punching behavior. The test results indicated that all the test specimens suffered the typical punching-shear failure, and the higher punching strength and initial stiffness could be found in the specimen with inner steel trusses. The numerical models of tested specimens were analyzed in ABAQUS. These models were verified by comparing the results of the tests with the results of the analyzes, and subsequently the sensitivity of the punching capacity to different parameters was studied. Based on the test results, a modified critical shear crack theory, which could take the contribution of the steel trusses into account, was put forward to predict the punching strength of this novel RC slab-column connection, and the calculated results agreed well with the test results.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.26-29
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• 2006

A flat plate-column connection is susceptible to brittle punching shear failure, which may result in the necessity of shear reinforcement. In present study, experimental tests were performed to study the capacity of slab-column connections strengthened with lattice, stud rail, shear band and stirrup under gravity and cyclic lateral load. Among them, the capacity of the specimens with lattice are superior to the others due to the truss action of the lattice bars and dowel action of the longitudinal bars as well as the shear resistance of the web re-bar. On the other hand, the strengths of the specimens with stud rail, shear band and stirrup are lower than the estimated strength by the ACI, therefore design formulas of the ACI are needed to revise.

• 대한기계학회논문집A
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• 제33권11호
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• pp.1262-1266
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• 2009

The slab(flat) truss plate used for building construction is analyzed for vibration and noise. Using floor impact test and numerical method (FEM), both net form and traditional form are compared for vibration and noise. The results show that the frequencies of a net form are lower than those of a traditional form in the case of free vibration, and the noise values of a net form are lower than those of a traditional form for the range from 500 Hz to 2000 Hz.

• 한국발생생물학회지:발생과생식
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• 제21권1호
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• pp.55-62
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• 2017

We used flowcytometry to ploidy verification after that investigate difference between diploid and spontaneous triploid through the truss dimension and classical dimension at crucian carp, Carassius auratus, crucian carp C. cuvieri and common carp, Cyprinus carpio collected from Hangang river, Hantangang river, Imjingang river, Geumgang river, Yeongsangang river and Nakdonggang river, Korea. There were significant differences among the three species for the truss dimensions anterior origin of dorsal fin $(2){\times}$ anterior origin of anal fin (5), $2{\times}$ anterior origin of pelvic fin (6), $2{\times}$ origin of pectoral fin (7), posterior origin of dorsal fin $(3){\times}5$, $3{\times}6$, and $3{\times}7$ (P<0.05). There were no significant differences among the three species in the truss dimensions dorsal fin length ($2{\times}9$) and eye diameter (ED)(P>0.05). On the other hand, there were no significant differences in the several classical dimensions of each species (P>0.05). Three classical dimensions, most anterior extension of the head $(1){\times}2$, $1{\times}6$ and $2{\times}$ most posterior scale in lateral line (4) did not differ between the C. auratus diploid and spontaneous triploid (P>0.05). Two classical dimensions, $1{\times}6$ and longest length between most anterior extension of the head and gill cover ($1{\times}8$) did not differ between the C. cuvieri diploid and spontaneous triploid (P>0.05). One classical dimensions, $1{\times}2$ did not differ between the common carp diploid and spontaneous triploid (P>0.05). There were significant differences in the each diploid and triploid species (P<0.05). These results suggest that the classification of each species and classification between diploid and spontaneous triploid morphometrical parameters used in this study are useful indices of morphometrical status in the each species from major river of Korea.