• Steel and Composite Structures
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• v.1 no.1
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• pp.1-16
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• 2001

Due to aesthetic, economic, and structural performance, the use of structural hollow sections as columns in both continuous moment resisting and nominally pinned construction is attractive. Connecting the beams to these sections is somewhat problematic as there is no access to the interior of the section to allow for the tightening of a standard bolt. Therefore, bolts that may be tightened from one side, i.e., blind bolts, have been developed to facilitate the use of site bolting for this arrangement. This paper critically reviews available information concerning blind bolting technology, especially the performance of fasteners in shear, tension, and moment resisting connections. Also provided is an explanation of the way in which the results have been incorporated into design guidance covering the particular case of nominally pinned connections. For moment resisting connections, it is concluded that whilst the principle has been adequately demonstrated, sufficient data are currently not available to permit the provision of authoritative design guidance. In addition, inherent flexibilities in the connections mean that performance equivalent to full strength and rigid is unlikely to be achievable: a semicontinuous approach to frame design will therefore be necessary.

• Tunnel and Underground Space
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• v.8 no.4
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• pp.261-274
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• 1998

The brief results of laboratory and field tests of yieldable steel arches are represented. The test supports were fabricated with three U-sectional beams which are 25.8 kg/m of Glocken profile. The structural analyses of semi-circular and arch supports were conducted to find out shape factor of U beam to be 1.35 and the location of 2nd plastic hinges. Load capacity of arch supports under crown loading were examined as a function of leg length. Yieldable characheristics of test supports were investigated with various bolting torque of connection part. Determination method of bolting torque were also studied. Finally, test supports were installed in-situ with torque of 21 kg .m, which showed a typical yielding procedure.

• Korean Journal of Medicinal Crop Science
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• v.5 no.3
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• pp.191-195
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• 1997

This study was conducted to obtain the basic information on setting up selection procedure using seedling characteristics in Angelica gigas Nakai lines. Morphological characteristics of the seedlings including height, leaf and petiole length among lines tested showed difference significantly, meaning that earlier selection was possible. Bolting rate at maturity ranged from 0.6 to 74.6% and root yield did from 350 to 3,893kg/ha. Root yield was increased in the lines with below 5% bolting rate. Heritabilities of petiole length, seedling height and leaf length in seedling stage bolting rate and root yield were high, while those of leaf length, root diameter and root length were relatively low. Bolting rate at maturity was positively correlated with seedling height, leaf length, leaf width, petiole length and number of leaves. A highly significant negative correlation was showed between root yield and seedling height, leaf length and width, petiole length, number of leaves, root length or bolting rate. From the above results the selection markers were found to be height, leaf length and petiole length in seedling stage.

• Korean Journal of Plant Resources
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• v.20 no.4
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• pp.331-335
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• 2007

This study was conducted to investigate the soil mulching effect on bolting and growth of Angelica koreana Max. The bolting ratio were 8.4% of non-mulching, 11.4% of black polyethylene film, 13.6% of transparent polyethylene film, 6.4% of rice-straw mulching. The mulching of polyethylene film induced higher bolting response than other materials. The radical leaf length, the number of leaf and crown in black P.E. film mulched were all higher than those of non-mulching and rice-straw mulching. The yield of the underground part of P.E film mulching was higher than non-mulching and rice-straw mulching. Comparing with other treatments, the dry root yield of black P.E. film mulching showed the most.

• Korean Journal of Medicinal Crop Science
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• v.10 no.1
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• pp.46-50
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• 2002

In DNA level, genetic study of Angelica species was firstly conducted to discriminate the bolting-resistant or low bolting variety, so called as Manchu, from other Korea collected lines and also this technuque was applied to identify the origin of commercial dried materials obtained from current oriental medicinal market. By RAPD analysis with 72 primers including sixty of 10-mers and twelve of 20-mers, respectively, three primers, which were related to the bolting resistant traits of Angelica gigas, were identified. Comparing the RAPD bands, URP04 primer showed the 1.7 kb specific band, which seemed to be related to delaying bolting traits, since it was observed only in Jinbu elite lines but not in others. On the other hand, since 1.2 kb band amplified by OPD11 was observed in other collected lines but not in Manchu var. and Jinbu line, this primer also could be considered as a selection marker for identifying bolting resistant or delaying bolting traits. In the same manner, since OPP09 did not show 1 kb major band but produced 0.8 kb and 1.2 kb bands in Manchu var., these three bands amplified by the primer could be considered one of the important key specifying Manchu var. related with the trait of Angelica gigas. OPC02 primer showed the same band patterns in all Korean collected lines, but not in other foreign introduced lines, such as A. sinensis from China, and A. acutiloba from Japan. Since these four RAPD primers, OPD11, OPP09, URP04, and OPC02 showed the specific polymorphisms in Angelica species, thus, these were useful to discriminate the three Angelica species, A. gigas, A. sinensis, and A. acutiloba.

• Structural Engineering and Mechanics
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• v.10 no.3
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• pp.211-226
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• 2000

A procedure has been developed for bolting steel plates to the sides of existing reinforced concrete beams which can be used to increase the shear strength of beams, increase the flexural strength of beams with enhanced ductility or with only a small loss of ductility, and increase the stiffness of beams in order to reduce deflections and crack widths. It will be shown in this paper, through a qualitative analysis and through the results of testing eight large scale beams, that standard rigid plastic analysis techniques which are commonly used in the design of reinforced-concrete, steel, and composite steel and concrete beams cannot be used directly to design composite bolted-plated reinforced-concrete beams. In the companion paper, quantitative procedures will be used to adapt the standard rigid plastic analysis techniques for this relatively new form of retrofitting.

• Journal of Power System Engineering
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• v.5 no.4
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• pp.38-43
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• 2001

This paper describes the effect of dynamic characteristics in tube line by external vibration conveying fluid with the power steering system. By the experimental analysis we found out that the factor of system vibration is the fluid-structure interaction of tube line. In fluid-filled tube system we study on the influence that the natural frequency of system and the frequency of wave motion produce upon through experiment. Experiments are modal test, frequency response function in continuous system, and vibrating tests when the system is driving with bolted clamping joint condition. From the results of the experimental studies, we obtained that the natural frequencies of system are very important than the wave induced vibrations. And we found that the tendency of system vibration level was decreased by bolting force, bolting condition and clamping distance.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.31-37
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• 2011

Construction automation is yet to be improved since construction site still faces a lot of high risks and difficulties. This research focuses on applying robotic beam assembly system in place of construction workers. This system consists of CF (Construction Factory) structure to provide adequate working environment to robot automation. The CF structure not only gives automation environment for a robot but also houses the equipments to protect from outside effects. The robotic beam assembly system also consists of robotic bolting system and robot transport mechanism. It utilizes various tools to insert and join the bolts and nuts. Visual servoing helps precise robot motion by sensing bolt hole and tail of the bolt. ITA system helps non skilled workers to easily perform the assembly work with the robot system. The robot transport mechanism includes sliding rail and cross-wired lift. It carries the robot to a desired position for assembly work.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.57-58
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• 2011

• Journal of Korean Society of Steel Construction
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• v.11 no.4 s.41
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• pp.351-362
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• 1999

Damage detection methods which utilize the change in dynamic characteristics are very hard to apply to large civil structures since local damage hardly affects global dynamic characteristics. But, if there is a very important and critical member and we focus only on the local behavior of it, it would be possible to detect damage from the change in local dynamic characteristics, such as natural frequencies and mode shapes .In this study, the cable anchorage part of a cable-stayed bridge under construction is modeled and analyzed by commercial finite element program, ABAQUS. It has both welding and bolting connections with a cable and a stiffening plate, and has a possible high stress concentration portions in it. Several damage scenarios such as crack through the welding or crack through the bolting connection are examined. The result shows that the local natural frequencies of the damaged member decrease up to 16% compared with that of the undamaged member. It is concluded that there is quite a high feasibility that the damage of the cable anchorage can be detected by measuring local dynamic characteristics.