• Structural Engineering and Mechanics
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• 제81권4호
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• pp.513-522
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• 2022

Steel-concrete composite segments replacing the conventional reinforced concrete segments can provide the rectangular shield tunnel superiorities on bearing capacity, ductility and economy. A simplified model with high-efficiency on computation is proposed for investigating the nonlinear response of the rectangular tunnel lining composed of composite segments. The simulation model is developed by an assembly of nonlinear fiber beam elements and spring elements to express the transfer mechanism of forces through components of composite segments, and radial joints. The simulation is conducted with the considerations of material nonlinearity and geometric nonlinearity associated with the whole loading process. The validity of the model is evaluated through comparison of the proposed nonlinear simulation with results obtained from the full-scale test of the segmental tunnel lining. Furthermore, a parameter study is conducted by means of the simplified model. The results show that the stiffness of the radial joint at haunch of the ling and the thickness of inner steel plate of segments have remarkable influence on the behaviour of the lining.

• 한국실내디자인학회논문집
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• 제12호
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• pp.91-99
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• 1997

Alvar Aalto has pursued National Romanticism, cultural art movement in scandinavian peninsula, organic concepts of growth and suitability, comprehensive view of nature including a possibility of coexistance of human-being and the nature well harmonized. For instance, his design expressed local features of the nature, human emotions instead of geometical arts and mathematical principles. It is noteworthy today that he built up the identity with satrical architecture vocabularies, different from modern arch-itechtural idiology. The characte-ristics of his design related to interior architecture are collectively as follows; The first, Space discontinuity of the interior and exterior, gradual process by joints which are inclined to collage with many shapes in plan and section of the space and such joints are adjusted by sensual ways and stressed with inner collectivity in his works. The second, He pursued the architectural orderfor modern irreqularity, various changes and sensual harmonies. As result, free curved line, fan shape and irregular modeling were individually expressed by technics of natural features and national characteristics of Finland. The third, Organic synthesis. A harmony through med-ums in its space, materials and space effectiveness relations are made and expressed for mixed design especially harmonized of all the materials he planned, entire harmony with total design, itemized details, materials and furnitures in entire space. The fourth, The interest of the nature based on his sense harmonized with nature made him mainly use native materials, lumbers and red bricks masonry and showed and arranged various interior sky light and grazed in to let natural light in, harmony with garden to sensually cohere to the nature and courtyard, etcetera. His major subject are to direct architectural developments through the nature and human-being in his works. At this point, it is considered that his direction of the locality and independence as a human-being made the concepts of organic space structure possible.

• Structural Engineering and Mechanics
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• 제83권5호
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• pp.693-707
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• 2022

Bonded joints have proven their performance against conventional joining processes such as welding, riveting and bolting. The single-lap joint is the most widely used to characterize adhesive joints in tensile-shear loadings. However, the high stress concentrations in the adhesive joint due to the non-linearity of the applied loads generate a bending moment in the joint, resulting in high stresses at the adhesive edges. Geometric optimization of the bonded joint to reduce this high stress concentration prompted various researchers to perform geometric modifications of the adhesive and adherends at their free edges. Modifying both edges of the adhesive (spew) and the adherends (bevel) has proven to be an effective solution to reduce stresses at both edges and improve stress transfer at the inner part of the adhesive layer. The majority of research aimed at improving the geometry of the plate and adhesive edges has not considered the effect of temperature and water absorption in evaluating the strength of the joint. The objective of this work is to analyze, by the finite element method, the stress distribution in an adhesive joint between two 2024-T3 aluminum plates. The effects of the adhesive fillet and adherend bevel on the bonded joint stresses were taken into account. On the other hand, degradation of the mechanical properties of the adhesive following its exposure to moisture and temperature was found. The results clearly showed that the modification of the edges of the adhesive and of the bonding agent have an important role in the durability of the bond. Although the modification of the adhesive and bonding edges significantly improves the joint strength, the simultaneous exposure of the joint to temperature and moisture generates high stress concentrations in the adhesive joint that, in most cases, can easily reach the failure point of the material even at low applied stresses.

• 한국강구조학회 논문집
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• 제13권4호
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• pp.327-335
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• 2001

강관 적층용접부에서 발생하는 잔류응력의 특징과 생성 메커니즘을 밝히기 위해 유한요소법을 이용한 3차원 열탄소성 해석을 수행하였다. 용접에 의해 강관을 접합할 때, 원주방향잔류응력과 두께방향잔류응력은 강관 내 외부에서 모두 접합부에서 인장응력이 발생하고, 길이방향잔류응력은 강관 내무에서 인장응력, 외부에서 압축응력이 발생된다. 또한 강관 적층 용접부의 잔류응력 생성기구를 명확히 하였다. 그 결과, 강관의 용접에 의한 잔류응력은 열응력에 의해 발생 할 뿐만 아니라, 강관의 기하학적 형상변화에 의한 영향도 받는다는 것을 밝혔다. 그리고, 용접조건과 강관의 제원이 달라질 경우에도 잔류응력 생성기구가 변함이 없음을 밝혔다.

• 콘크리트학회논문집
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• 제28권2호
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• pp.129-139
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• 2016

대형 PC기둥의 양중부하를 줄이고 접합부의 구조일체성을 개선하기 위한 대안으로서, 중공 PC기둥이 사용될 수 있다. 본 연구에서는 PC부의 생산성과 구조일체성을 개선한 새로운 중공 PC기둥을 개발하였다. PC부를 제작하기 위하여 구조용 골형플레이트를 내부영구거푸집과 수평 관통철근을 사용하였다. 제안된 PC기둥의 내진성능을 검증하기 위하여, 1/2 스케일의 기둥 실험체 4개에 대하여 일정 축력에서 반복 횡가력실험을 수행하였다. 실험 변수로는 횡철근 간격, 강섬유 사용여부, 그리고 PC부의 두께가 고려되었다. 실험 결과, 제안된 PC기둥은 외곽 PC부의 취성적인 파괴 없이 우수한 하중재하능력과 변형능력을 보이는 것으로 나타났다. PC부에 횡철근을 촘촘히 배근하거나 강섬유를 사용할 경우, PC 콘크리트의 탈락을 제한하여 변형능력을 증가시킬 수 있었다.

• 한국기계가공학회지
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• 제19권10호
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• pp.52-58
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• 2020

Bellows are corrugated mechanical elements used to absorb displacements or vibrations caused by temperature changes, pressure, earthquakes, waves, etc., which are welded to flanges or directly connected to pipes. Expansion joint bellows must not only be designed to sufficiently withstand the internal pressure of the pipes but also accommodate axial, transverse, and rotational deformations to minimize the transfer of forces to the sensitive components of the system. Bellows have various types of corrugations, but U-type bellows are most commonly used in general piping systems. In this study, the behavior of U-shaped one-, two-, and three-ply bellows with the same inner diameter under pressure and forced displacement was analyzed using the finite element method. The results were compared with the design formula in the Expansion Joint Manufacturers Association (EJMA)'s code. Manufacturer data were used for the applied pressure and force displacement. The behavioral characteristics of the three cases were compared via structural analysis because the stress levels will be different for each model, even if they have the same inner diameter. Since the analytical model has an axisymmetric shape but displacement occurs in the transverse direction, the finite element model was composed of 1/2 of the whole model, and ANSYS Workbench 17.2 was employed for the analysis.

• 한국CDE학회논문집
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• 제18권1호
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• pp.10-20
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• 2013

The Yoon Jeung residence is a well-known and prototypical aristocratic house example showing typical and interesting characteristics of the traditional houses in the middle region of Korea. When it comes to understanding the architectonic characteristics of a Korean traditional house, it was not easy to actually capture the compositional and/or constructional knowledge of the building even though it is a wooden building with many wooden members showing their compositional relations. Now with the help of the BIM tool, the Building Information Modeling tool, we could actually be able to compare and analyze each member and their compositional relations. In this paper we examine the unique traditional composition method used in extending the building's structural sections utilizing the bended-joint characteristics of traditional buildings with exemplar case of the Yoon Jeung residence. Thereby we examine those relationships among three major compositional parts namely the plan based spatial compositions, the upper wooden compositions and the roof forms so as to specify the building's typical characteristics with reasonably acceptable causes. The inner and outer block of the residence are handled with their bended-joints with more detailed knowledge of categorization by way of joint relationships among members.

• 한국멀티미디어학회논문지
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• 제10권6호
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• pp.716-725
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• 2007

In this paper we describe a motion tracking algorithm for 3D human animation using stereo vision system. This allows us to extract the motion data of the end effectors of human body by following the movement through segmentation process in HIS or RGB color model, and then blob analysis is used to detect robust shape. When two hands or two foots are crossed at any position and become disjointed, an adaptive algorithm is presented to recognize whether it is left or right one. And the real motion is the 3-D coordinate motion. A mono image data is a data of 2D coordinate. This data doesn't acquire distance from a camera. By stereo vision like human vision, we can acquire a data of 3D motion such as left, right motion from bottom and distance of objects from camera. This requests a depth value including x axis and y axis coordinate in mono image for transforming 3D coordinate. This depth value(z axis) is calculated by disparity of stereo vision by using only end-effectors of images. The position of the inner joints is calculated and 3D character can be visualized using inverse kinematics.

• Progress in Superconductivity
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• 제3권1호
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• pp.104-110
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• 2001

Since the strand-to-strand type joint far CICC (Cable-In-Conduit Conductor) is small in size and has low DC resistance, it is expected to be useful type fur a superconducting magnet system which had a compact structure like the KSTAR (Korea Superconducting Tokamak Advanced Research) coil system. The DC resistance is changed according to the distribution patterns of strands in cables connected together in the joint. A commercial code was used for the calculation of the DC resistance. With the decrease of outer diameter of the Joint, Which means the increase of strand volume fraction in the joint, the calculated DC resistance decrease rapidly and non-lineally. The variation of resistance depends mainly on the volume fraction of solder which has higher resistivity than copper. The resistance decrease inversely with the increase of the length of the joint. The resistance increase with increase of number of triplets in each stack contacted with that of another terminal cable. In case of the strand-to-strand joint that has 62mm of outer diameter, 52mm of inner diameter, 100mm of overlap length, and four triplets in each stack, the calculated DC resistance is less than 1 n-Ohm.

• 오토저널
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• 제13권5호
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• pp.42-50
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• 1991

According as the members and inner and outer plates of the automobile body structure have been thinned their thickness and have become high strength, each part of the body structure has been put more severe stress condition. Therefore, it has been increasingly required to improve the fatigue strength of the spot welded structures. As one of the improving methods for such problem, the author had previously proposed the method of alleviating stress concentration at nugget edge of the spot weld part and improving its fatigue strength [1]. But, because fatigue strength of the spot welded lap joint is influenced by its geometrical and mechanical factors, welding condition and etc., there needs a quantitative and systematic estimation method of them. In this report, by considering nugget edge of the spot weld part of the spot welded lap joint subjected to tensile load to the ligament crack, fatigue strength of various spot welded lap joints was estimated with the stress intensity factor (S.I.F.) K which is fracture mechanical parameter. It is known that evaluation of fatigue strength of the spot welded lap joint by the stress intensity factor (S.I.F.) K is more effective than the maximum stress $(\sigma_{ymax}$) at edge of the spot weld part on the center line of width of the plate.