• Steel and Composite Structures
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• v.46 no.4
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• pp.539-551
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• 2023

In order to study the fire resistance of castellated composite beams with ortho-hexagonal holes and different beam-end restraints, temperature rise tests with constant load were conducted on full-scale castellated composite beams with ortho-hexagonal holes and hinge or rigid joint constraints to investigate the temperature distribution, displacement changes and failure patterns of castellated composite beams with two different beam-end constraints during the whole course of fire. The results show that (1) During the fire, the axial pressure and horizontal expansion deformation generated in the rigid joint constrained composite beam were larger than those in the hinge joint constrained castellated composite beam, and their maximum horizontal expansion displacements were 30.2 mm and 17.8 mm, respectively. (2) After the fire, the cracks on the slab surface of the castellated composite beam with rigid joint constraint were more complicated than hinge restraint, and the failure more serious; the lower flange and web at the ends of the castellated steal beams with hinge and rigid joint constraint produced serious local buckling, and the angles of the ortho-hexagonal holes at the support cracked; the welds at both ends of the castellated composite beam with rigid joint constraint cracked. (3) Based on the simplified calculation method of solid-web composite beam, considering the effect of holes on the web, this paper calculated the axial force and displacement of the beam-end constrained castellated composite beams under fire. The calculation results agreed well with the test results.

• Steel and Composite Structures
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• v.18 no.1
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• pp.135-148
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• 2015

The cutout hole locating at the place of rib-to-diaphragm welded connection is adopted to minimize the restraint, which is caused by the floor-beam web to rib rotation at the support due to the unsymmetrical loads in orthotropic deck. In practice, an inevitable problem is that there is a large number of welding joint's cracks formed at the edge of cutout hole. In this study, a comparative experiment is carried out with two types of cutout hole, the circular arc transition and the vertical transition. The fatigue life estimation of specimens is investigated with the application of the structural hot spot stress approach by finite element analyses. The results are compared with the ones of the fatigue tests which are carried out on these full-scale specimens. Factors affecting the stress range are also studied.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.165-166
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• 2012

A thermal stresses by heat of hydration was analyzed according to a change of a pour height in reactor containment building. In case of more than 3.6m pouring height a crack index by heat of hydration analysis resulted in less than 1 because there is not a construction joint of vertical direction and for a self-restraint effect of circumferential section shape. Therefore detailed consideration on a mixture proportion of binder type, quantity in concrete and selection of a form in seasonal air temperature is needed for a control of tensile stress by heat of hydration.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.12
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• pp.182-191
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• 2004

This study is focused on the development of a child human model, which is composed of skin, skeleton, joints and muscle, etc. The dimension of child outer skin is referred to anthropometric data from KRISS (Korea Research Institute of Standards and Science). The positions of joint and mass properties of body segments are calculated from ATB(Articulated Total Body) program, GEBOD. The properties of bones and muscles are obtained by the way of scaling from adult human model. To verify the developed human model, ROM simulation and sled test is conducted. Developed human model can be effectively applied to the evaluation of human injury in crash situation and development of child restraint system. The explicit finite element program $PAM-CRASH^TM$ was used to simulate six-year old child human model.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.10a
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• pp.230-238
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• 1996

Recently, square hollow section (S.H.S) is frequently used for column and H-section for beam of steel building structures. The connection between S.H.S column and H-beam is found to weaken the rotational restraint of the joint. Several types of detail to overcome the problem have been suggested for the connection between concrete filled S.H.S column and concrete composited H-bean In this paper, modelling technique to monitor the behavior of the connections is proposed. Then, Drucker-Prager yield criteria is introduced to simulate yield behavior of in-fill concrete while Von-Mises was used in earlier works. Gap-elements are also introduced to simulate the interaction between S.H.S columns and the in-fill concrete as in privious papers. axial forces are applied to S.H.S columns and made to vary in intensity and eccentricity.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1093-1098
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• 2007

In designing the high-speed railroad track, it is important to utilize appropriate track components to maintain uniform stiffness and ensure track alignment within the tolerance set for that system. In this regard, continuous welded rails (CWRs) were introduced to the Korean railways. Yet the installation of CWRs can result in an adverse impact due to the track/structure interaction on bridge sections yielding variations in the stiffness at the expansion joints. It may also impose additional axial force, generate excessive stress or deflection on track, and loosen the ballast at the ends as a bridge deck contracts or expands owing to a thermally-induced dynamic response. The risk is even greater in a long bridge deck, resulting in track longitudinal irregularities, deteriorating passenger's comfort, and increasing maintenance efforts. This study evaluates the performance of ZLR and their impact on track longitudinal irregularities through the track measuring results on a test section installed the ZLR in order to minimize the thermally-induced responses and the maintenance efforts for the high speed railway bridges.

• Clinics in Shoulder and Elbow
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• v.2 no.2
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• pp.138-142
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• 1999

Coracoclavicular ligament is main restraint to superior instability of the distal clavicle. Coracoacromial ligament, extensor tendon of toe, palmaris longus tendon, and Dacron tape have been used to reconstruct coracoclavicular ligament. We used semitedinosus tendon to reconstruct coracoclavicular ligament. The semitendinosus tendon was harvested as a usual fashion. After the distal clavicle and coracoid process were exposed, a hole of six millimeter diameter was made on the center of whole thickness of the distal clavicle. A malleolar screw was fixed from distal clavicle to coracoid process to maintain the reduced position of the acromioclavicular joint. The leading suture of tendon graft was passed through the hole of the distal clavicle and looped under the coracoid process. After leading portion of ten­don graft was looped over the clavicle, sutures were made between each end of the tendon graft with nonabsorbable suture materials.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.4
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• pp.219-223
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• 2002

The actual behavior of joint is traditionally disregarded in steel frame design. In fact, the structural analysis of steel frames is generally carried out by assuming that joints fulfil the ideal condition of either a hinge or a fixed-end restraints. In this way, calculations are made somewhat simpler, but the structural model is not able to reflect the actual structural response. Therefore, steel frame classification system for estimation or analysis about behavior of steel frame should be established, and range that each connections belongs should be divided definitely. This research presents realistic and practical moment-rotation relation through investigation and analysis of steel frame beam-to-column classification system.

• International Journal of Highway Engineering
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• v.16 no.2
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• pp.25-34
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• 2014

PURPOSES : This paper numerically evaluates the contribution of transverse steel to the structural behavior of continuously reinforced concrete pavements to understand the role of transverse steel. METHODS : Two-lane continuously reinforced concrete pavements with and without transverse steel were analyzed through finite element analysis with the aid of commercial finite element analysis program DIANA; the difference in their structural behavior such as deflection, joint opening, and stress distribution was then evaluated. Twenty-node brick elements and three-node beam elements were used to model concrete and steel, respectively. Sub-layers were modeled with horizontal and vertical tensionless spring elements. The interactions between steel and surrounding concrete were considered by connecting their nodes with three orthogonal spring elements. Both wheel loading and environmental loading in addition to self-weight were considered. RESULTS : The use of transverse steel in continuously reinforced concrete pavements does not have significant effects on the structural behavior. The surface deflections change very little with the use of transverse steel. The joint opening decreases when transverse steel is used but the reduction is quite small. The transverse concrete stress, rather, increases when transverse steel is used due to the restraint exerted by the steel but the increase is quite small as well. CONCLUSIONS : The main role of transverse steel in continuously reinforced concrete pavements is supporting longitudinal steel and/or controlling unexpected longitudinal cracks rather than enhancing the structural capacity.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.4
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• pp.95-104
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• 1999

Use of the ultra thick plate is being continuously increased in large off-shore structures, ships, bridges and skyscraper construction, due to increasingly large-sized steel structures and it seems that this trend will be maintained. But, occurrence of the lamella tearing has been reported in ultra thick plate used for construction. It is reportedly caused by impurities such S(sulfur), P(phosphorus) and others accumulated in the ultra thick plate's centerline in the thickness direction with strip shape or by restraint residual stress caused by the welding. In the ultra thick plate made by continuous casting method, occurrence of lamination is difficult to avoid because of the properties of production procedure. Therefore, with a view to reducing the lamella properties, this report tries tearing in the steel structure in the view of welding strength rather than metallic properties, this report tries to seek the optimum groove and welding procedure by using the computer simulation based on FEM(Finite Element Method).