• Title/Summary/Keyword: Cross-member

Search Result 359, Processing Time 0.021 seconds

The Influence of the Loading Sizes on Natural Frequency of the Advanced Composite Material Structures (복합신소재구조물의 고유진동수에 대한 하중크기의 영향)

  • Han, Bong Koo
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.17 no.3
    • /
    • pp.20-27
    • /
    • 2013
  • Simple Iteration Method for calculating the natural frequency is presented in this paper. This method is simple but exact method of calculating natural frequencies corresponding to the modes of vibration of beams and tower structures with irregular cross sections and arbitrary boundary conditions. This method consists of determining the deflected mode shape of the member due to the inertia force under resonance condition. Finite difference method is used for this purpose. The influence of the $D_{22}$ stiffness on the natural frequency is rigorously investigated. In this paper, the influence of the loading sizes, different cross section on the natural frequency of vibration of some structural elements is presented. This method extends to two dimensional problems including advanced composite material structures.

CD30-Mediated Regulation of Cell Adhesion Molecule Expression on Murine T Cells

  • Nam, Sang-Yun
    • IMMUNE NETWORK
    • /
    • v.3 no.1
    • /
    • pp.8-15
    • /
    • 2003
  • Background: CD30 is a member of TNF receptor family and expressed on lymphocytes and other hematopoietic cells following activation as well as Hodgkin and Reed-Sternberg cells in Hodgkin's lymphoma. In this study, CD30-mediated regulation of cell adhesion molecule expression on normal activated mouse T cells was investigated. Methods: Mouse T cells were activated with anti-CD3 antibody for induction of CD30, which was cross-linked by immobilized anti-CD30 antibody. Results: High level of CD30 expression on T cells was observed on day 5, but only little on day 3 even under culture condition resulting in an identical T cell proliferation, indicating that CD30 expression requires a prolonged stimulation up to 5 days. Cross-linking of CD30 alone altered neither proliferation nor apoptosis of normal activated T cells. Instead, CD30 appeared to promote cell adherence to culture substrate, and considerably upregulated ICAM-1 and, to a lesser extent, ICAM-2 expression on activated T cells, whereas CD2 and CD18 (LFA-1) expression was not affected. None of cytokines known as main regulators of ICAM-1 expression on tissue cells (IL 4, $IFN{\gamma}$ and $IFN{\alpha}$) enhanced ICAM-1 expression in the absence of CD30 signals. On the other hand, addition of $NF-{\kappa}B$ inhibitor, PDTC (0.1 mM) completely abrogated the CD30-mediated upregulation of ICAM-1 expression, but not CD2 and ICAM-2 expression. Conclusion: This results support that CD30 upregulates ICAM-1 expression of T cell and such regulation is not mediated by higher cytokine production but $NF-{\kappa}B$ activation. Therefore, CD30 may play important roles in T-T or T-B cell interaction through regulation of ICAM-1, and -2 expression.

A Study on the Load Carrying Capacity and Deformation Capacity of the Internal Anchors Welded Cold Formed Concrete Filled Columns (내부앵커형 콘크리트 충전 기둥의 내력 및 변형능력에 관한 연구)

  • Kim, Sun Hee;Yom, Kong Soo;Choi, Sung Mo
    • Journal of Korean Society of Steel Construction
    • /
    • v.25 no.4
    • /
    • pp.347-357
    • /
    • 2013
  • Recently, In recognition of outstanding structural performance the use of Concrete Filled steel Tube(CFT) columns has been increased. Research is ongoing that effective use of cross-sectional because steel strength development and rising prices. In this Lab, suggests new shape by Thin steel plates bent to be L-channel welded to form square steel tube to maximize efficiency of the cross section. In addition, since the rib placed at the center of the tube width acts as an anchor; higher load capacity of buckling is acceptable. we have developed New shape welded built-up square tube for broader usability which were bent to be L-shaped and thin Plate each unit member were welded. In order to apply the new shape built-up square columns, we predicted structure behavior, stress distribution with parameter Width thickness ratio. The experimental results presented in standards and even exceed the b/t of the rib anchors installed in the role due to exert enough strength and deformation to improve performance was favorable.

A Study on Plastic Fatigue of Structural Steel Elements under Cyclic Loading (반복하중을 받는 강구조 요소의 소성피로에 관한 연구)

  • Park, Yeon Soo;Park, Sun Joon;Kang, Sung Hoo;Yoon, Young Phil
    • Journal of Korean Society of Steel Construction
    • /
    • v.9 no.2 s.31
    • /
    • pp.193-204
    • /
    • 1997
  • In order to quantify the relationships of the important physical factors relating failure to strong earthquake loading, the plastic fatigue problems for structural components under repeated loading were reviewed first. A new concept of very low cycle fatigue failure for structural components under severe cyclic excitations as in strong earthquakes was represented. Also, an experimental study was made of the very low cycle fatigue failure of structural steel elements. It was attempted to realize the ultimate failure in the course of loading repetitions of the order of several to twenty. The test specimen had a form of rectangular plate, representing a thin-plated element in a steel member as wide-flange cross section. It was subjected to uniaxial loading repeatedly, until complete failure takes place after undergoing inelastic buckling, plastic elongation and/or their combination. It was seen as a result that the state of the ultimate failure is closely related to the maximum strain at the extreme fiber in the cross section.

  • PDF

The Development Process of Vehicle Roof Carrier using One Side Release System (측면 단동 릴리즈 시스템을 이용한 자동차용 루프 캐리어 개발 프로세스)

  • Jang, Dong-Hwan;Ko, Byung-Doo;Lee, In-Chul
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.27 no.5
    • /
    • pp.56-62
    • /
    • 2010
  • This paper presents the development process of roof carrier assembly using a one side release system for a vehicle. An RV(Recreational Vehicle) or SUV(Sports Utility Vehicle) has a roof carrier system on an upper surface of a roof panel for loading large or long size baggage. Such a roof carrier system is comprised of a roof rack longitudinally mounted on a roof panel and cross bar perpendicularly installed in the horizontal direction. Several locking mechanisms used in most vehicle roof carrier systems are composed with both side releasable locking ones. The obvious drawback to this arrangement is that when the user desires to reposition the cross bar, first one of the locking members must be unlocked and then the user must walk around to the opposite side of the vehicle to unlock the other member. In this paper, we proposed a newly locking mechanism, which allows a user simultaneously place both locking members of the roof carrier in locked and unlocked positions. In order to estimate design compatibility, structural and modal analysis is performed. Furthermore, a prototype based on the proposed design has been made, and then durability test carried out. From the simulation and experimental results, the proposed roof carrier system is proved effective and safe.

An Experimental Study on the Bending Behaviour of Steel Grid Composite Deck (격자형 강합성 바닥판의 휨거동에 대한 실험적 연구)

  • Shin, Hyun Seop;Lee, Chin Hyung;Park, Ki Tae
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.15 no.4
    • /
    • pp.175-184
    • /
    • 2011
  • To take advantage of reduced on-site construction periods and minimize traffic impacts various types of steel grid composite deck have been developed since 1930's. Modular prefabricated unfilled grid decks permit a long-distance transportation and construction under unfavorable condition, for example, in mountainous regions due to its comparatively light-weighter structure than fully filled grid deck. In this study bending tests of unfilled grid decks for the deck member of various kinds of infrastructure are carried out, bending strength and behaviour of composite action are experimentally evaluated. In this bending test, design variables are considered, such as type of shear connection between steel grid and concrete slab, spacing between cross bars and thickness of concrete slab. Through test results bending strength and behaviour of composite action are evaluated, reference data for proper type of shear connection and other details of the deck, such as spacing between cross bars, are obtained.

Lateral-Torsional Post-Buckling Analyses of Thin-Walled Space Frames with Non-symmetric Sections (비대칭단면을 갖는 박벽 공간뼈대구조의 횡-비틂 후좌굴 유한요소해석)

  • Park, Hyo Gi;Kim, Sung Bo;Kim, Moon Young;Chang, Sung Pil
    • Journal of Korean Society of Steel Construction
    • /
    • v.11 no.2 s.39
    • /
    • pp.153-165
    • /
    • 1999
  • In order to trace the lateral-torsional post-bucking behaviors of thin-walled space frames with non-symmetric cross sections, a geometrically non-linear finite element formulation is presented by applying incremental equilibrium equations based on the updated Lagrangian formulation and introducing Vlasov's assumption. The improved displacement field for non-symmetric thin-walled cross sections is introduced based on inclusion of second order terms of finite rotations, and the potential energy corresponding to the semitangential rotations and moments is consistently derived. For finite element analysis, tangent stiffness matrices of thin-walled space frame element are derived by using the Hermition polynomials as shape functions. A co-rotational formulation in order to evaluate the unbalanced loads is presented by separating the rigid body rotations and pure deformations from incremental displacements and evaluating the updated direction cosines and incremental member forces.

  • PDF

Validity Field Testing of Family Nursing Phenomen in Korea by the Retrospective Method of ICNP (ICNP의 후향적 방법에 의한 한국가족현상의 실무타당성 검증연구)

  • Kim, Hyun-Sook;Kwon, Yong-Suk;Park, Kyung-Min;Kee, Ji-Hyun;Ko, Young-Ae;So, Ae-Young;Yang, Soon-Ok;Kim, Young-Im;Kim, Hee-Girl;Oh, Jin-Joo;Wang, Myoung-Ja;Kim, Soon-Lae;Yun, Soon-Nyung
    • Research in Community and Public Health Nursing
    • /
    • v.13 no.3
    • /
    • pp.423-432
    • /
    • 2002
  • This study was conducted to test the validity of characteristics of family nursing phenomena in Korea identified in a previous study by Yoon, S. Y, et al. (1999). Data for this study were collected from 355 (first measurement 186, second measurement 169) nurses whose family nursing careers were more than one year using a cross sectional survey method. The distribution per one characteristic ranged between 0 to 5. The phenomena that had two or more characteristics and had a score of 3.0 points or more included disturbance in marital role', 'disturbance in family communication', 'inappropriate family coping', 'lack of family intimacy', 'unhealthy life style', 'deficit of financial management skill and support', 'inadequate care management sick member', and' inadequate home-making'. The essential characteristics of the 8 phenomena presented above included 27 items. Further studies on family nursing phenomena in Korea are needed to support the evidence through surveys of families in the field. A reconfirmation study, as well as qualitative research on the low validity of the characteristics, needs to be more performed in the future.

  • PDF

Comparative elements and conflicts in the novel Nada, Carmen Laforet (『나다』에 투영된 대비적요소와 대립적요소의 의미)

  • Song, Sun-ki
    • Cross-Cultural Studies
    • /
    • v.27
    • /
    • pp.81-104
    • /
    • 2012
  • This paper looks into the complexity of the comparative and conflictive elements portrayed on the novel Nada. Through the interpretation of the actions of the female characters, we can classify them into two different categories: pro-Franco and anti-Franco system. Thus, for example, the character Ena is an active, intellectual and liberal woman capable to manipulate and control men who lives at her own free will. This active and liberal personality is clearly not the favored type of woman under Franco, which prefers a society where men are the dominant figures. Another female character, Gloria, places herself far from the Catholicism based morality during the Franco period as she is having an affair with her husband's brother. We also find examples of the opposite, that is, affinity with Franco ideals, such as Angustias' decision to become a member of the convent, in line with the motto "Spain, united and great, through Catholicism"; the example of Ena's mother, nurturing six sons and daughters, also resonates with Franco ideology of a woman's role in the Spanish society, being mostly a reproductive instrument. One of the topics of this novel is the confrontation between the prewar petit bourgeoisie and the new postwar bourgeoisie. We can appreciate a big difference between the lifes of Andrea's family and Pons' family. Andrea has friendly relationships with friends from the new bourgeoisie; however, these interactions are not genuine, but superficial. Because of that, we also conclude that this novel reflects the underlying conflicts between different social strata. We also observe the conflicts and confrontations between republicans and nationalists in this society, through the relationships between two brothers, Juan y $Rom{\acute{a}}n$. During the civil war, Juan collaborates with the national faction, while $Rom{\acute{a}}n$ joins the republican faction. Consequently, they separate from each other due to their different ideologies. We will conclude that this novel also reflects on the idea that the Spanish civil war destroyed fraternity and separated families.

Responding to the Spectral Voice of the Outcast: Reading of William Wordsworth's "The Thorn"

  • Kang, Heewon
    • Cross-Cultural Studies
    • /
    • v.36
    • /
    • pp.37-59
    • /
    • 2014
  • William Wordsworth's "The Thorn" revolves around the following questions: Who is Martha? Why does she go to the mountain top and repeat her doleful cry? To these questions, it gives us two different kinds of answers; one derives from the villagers, and the other from the narrator. This essay attempts to examine how the answers exemplify two different critical approaches to the problem of community, using Jacques Lacan's account of sexual difference in his seminar on Encore as a guiding thread of analysis. The important thing to retain here is that sexual difference in Lacan's seminar on Encore does not so much indicate biological determinations as two distinct forms of relating to the other which are intimately bound up with the question of how a community is constructed and maintained. The first form, called "masculine," suggests that it is a radical exception to a community that makes possible the community as a field of totality or sameness; the second form, called "feminine," shows that each of the subjects cannot be regarded as a member of a closed community which is guaranteed by the exceptionality, but as an exception that is radically singular. This in turn leads us to consider the possibility that the masculine form has to do with the villagers' effort to distinguish themselves from Martha and the feminine form with the way in which the narrator confronts and represents her. In the course of his formulation of sexuation graph, Lacan stresses that the masculine side must be supplemented by the feminine side, which allows us to elaborate on why, concerning Martha, the narrator does not just keep the completely different position from the villagers'. This is to say that the villagers' representation of Martha as an exception to the community should be supplemented by the narrator's attempt to tell Martha's story as the villagers do and at the same time to capture something of her enigmatic unrepresentability. Bearing in mind Charles Shepherdson's elaboration of traumatic memory, this essay also tries to clarify how the narrator preserves and even transmits something of Martha's truth that is embodied in her uncontrollable and unassimilable cry.