• Title/Summary/Keyword: post base connection

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Evaluation of Moment Resisting Post-Base Connection Using Multi-directional Connector (다방향 접합철물 삽입형 기둥-기초 접합부 모멘트 저항성능평가)

  • Kim, Keon-Ho;Lee, Sang-Joon
    • Journal of the Korea Furniture Society
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    • v.25 no.4
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    • pp.331-337
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    • 2014
  • The purpose of this paper is to evaluate the moment resistance of glulam post-to-base connections by applying quasi-static cyclic loads. The connectors consisted of inserted plates and drifted pins according to the load direction. The connection types employed in this study were total three including two unidirectional types (H, V) and the multi-directional type (M). The moment resistance of 8 mm-plate M-type is compared to 6 mm plate. Total four types of Post-to-base connection are prepared and tested under pseudo-static reversed cyclic loading. Test results showed that the yield moment of multi-directional connection is about 2 times higher than that uni-directional connections. The ductility ratio of multi-directional connection determined by EEEP was higher that that of uni-directional connection. It was becoming higher as the thickness of plate is increased. The Finite Element Analysis was conducted to estimate the stress distribution behavior of tested connections. Results showed the failure of multi-directional type were caused by the split of pined hole and the shear failure of lifted part of post.

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Analytical Study on Structural Behaviors of Post-Tensioned Column-Base Connections for Steel Modular Structures (철골 모듈러 구조물의 포스트텐션 기둥-바닥 접합부 거동에 대한 해석적 연구)

  • Choi, Kyung-Suk;Shin, Dong-Hyeon;Kim, Hyung-Joon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.33 no.6
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    • pp.427-435
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    • 2020
  • Modular structures are relatively lightweight compared to reinforced-concrete or steel structures. However, it is difficult to achieve structural integrity between the columns of unit modules in a modular structure, which causes undesirable effects on the lateral force resistance capacity against wind and earthquake loads. This is more prominent in modular structures whose overall heights are greater. Hence, a post-tensioned modular structural system is proposed herein to improve the lateral force resistance capacity of a typical modular structure. A post-tensioned column-base connection, which is the main component of the proposed modular structural system, is configured with shapes and characteristics that allow inducing self-centering behaviors. Finite element analysis was then performed to investigate the hysteretic behaviors of the post-tensioned column-base connection. The analysis results show that the hysteretic behaviors are significantly affected by the initial tension forces and beam-column connection details at the base.

Physical and mechanical changes on titanium base of three different types of hybrid abutment after cyclic loading

  • Rimantas Oziunas;Jurgina Sakalauskiene;Laurynas Staisiunas;Gediminas Zekonis;Juozas Zilinskas;Gintaras Januzis
    • The Journal of Advanced Prosthodontics
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    • v.15 no.1
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    • pp.33-43
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    • 2023
  • PURPOSE. This study investigated the physical and mechanical changes in the titanium base of three different hybrid abutment materials after cyclic loading by estimating the post-load reverse torque value (RTV), compressive side fulcrum wear pattern of titanium base, and surface roughness. MATERIALS AND METHODS. A total of 24 dental implants were divided into three groups (n = 8 each): Group Z, LD, and P used zirconia, lithium disilicate, and polyetheretherketone, respectively, for hybrid abutment fabrication. RTV was evaluated after cyclic loading with 50 N for 1.2 × 106 chewing cycles. The compressive sides of the titanium bases were analyzed using a scanning electron microscope, and the roughness of the affected areas was measured using an optical profilometer after loading. Datasets were analyzed using Kruskal-Wallis test followed by Mann-Whitney tests with the Bonferroni correction (α = .05). RESULTS. Twenty-three samples passed the test; one LD sample fractured after 770,474 cycles. Post-load RTV varied significantly depending on the hybridabutment material (P = .020). Group P had a significantly higher median of post-load RTVs than group Z (16.5 and 14.3 Ncm, respectively). Groups LD and P showed minor signs of wear, and group Z showed a more pronounced wear pattern. While evaluating compressive side affected area roughness of titanium bases, lower medians were shown in group LD (Ra 0.16 and Rq 0.22 ㎛) and group P (Ra 0.16 and Rq 0.23 ㎛) than in group Z (Ra 0.26 and Rq 0.34 ㎛); significant differences were found only among the unaffected surface and group Z. CONCLUSION. The hybrid abutment material influences the post-load RTV. Group Z had a more pronounced wear pattern on the compressive side of titanium base; however, the surface roughness was not statistically different among the hybridabutment groups.

Cyclic Behavior of Timber Column Concealed Base Joint

  • Humbert, Jerome;Lee, Sang-Joon;Park, Joo-Saeng;Park, Moon-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.41 no.2
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    • pp.123-133
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    • 2013
  • This paper presents experimental and numerical tests on a recently developed timber column concealed base joint. This joint was designed to replace the wood-wood connection found in the post-and-beam structure of Hanok, the traditional Korean timber house. The use of metallic connectors provides an increased ductility and energy dissipation for a better performance under reversed loading, especially seismic. In this study, we investigate the performance of the joint under pseudo-static reversed cyclic moment loading through the study of its ductility and energy dissipation. We first perform experimental tests. Results show that the failure occurs in the metallic connector itself because of stress concentrations, while no brittle fracture of wood occur. Subsequent numerical simulations using a refined finite element model confirm these conclusions. Then, using a practical modification of the joint configuration with limited visual impact, we improve the ductility and energy dissipation of the joint while retaining a same level of rotational strength as the originally designed configuration. We conclude that the joint has a satisfying behavior under reversed moment loading for use in earthquake resistant timber structure in low to moderate seismicity areas like Korea.

The Study on Globalization of Traditional Costume - Connection With Modernity and Post-Modernity - (전통 복식의 세계화에 대한 연구 - 근대성, 탈근대성과 관련하여 -)

  • 임영자;유순례
    • Journal of the Korea Fashion and Costume Design Association
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    • v.3 no.1
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    • pp.117-127
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    • 2001
  • In the 1980's discuss in the postmodernism and at the 1990's that is globalization. Globalization is the compression of time and space. That is the products of modernism and postmodernism. Global trends are the multiculturalism, localism, tribuism, etc. These trends have a important effect modern fashion. 20th fashion have a modernity -variation, functionalism and popularity, postmodernity-uncertainty, multiculturalism, post structuralism, etc. If Korean fashion have the globality, open to the world other country and culture, deep study of that, and view point of intercultureity. This Study Suggest to achieve globalize of Korean costume. 1. Plon up base on the scholastic study of giobalization. 2. Promote global project of Korean collection. 3. Collect of ethnic, culture, information of fashion America, Europe, etc. and make high up our a sense of disorimination. 4. Manifold studing abroad 5. Strergthening of globalization and ethnic curriculum on Educational course

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A Study on the Structural Standard of the Tube and Coupler Scaffold (단관비계의 구조규격에 관한 연구)

  • 이영섭
    • Journal of the Korean Society of Safety
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    • v.5 no.2
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    • pp.66-75
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    • 1990
  • This study is conducted to establish the structural standard of tube and coupler scaffold which is suitable for our present stuation through the comparison analysis for domestic and foreign standards as well as measurement of field survey. The results of this study are as follows : 1) The load is classified by three categories, light-duty(equal and lower than 150kg/m$^2$), medium-duty(150-250 kg/m$^2$), heavy-duty(250-350kg/m$^2$), and the equivalent horizontal length of side posts is each, 1.5-1.8m, 1.2-1.5m, equal and lower than 1.2m, and the equivalent horizontal length between front and rear posts is each 1.2-1.5m, 0.9-1.2m, equal and lower thatn 0.9m, in accordance with the load classification. 2) The height between upper and lower runner is equal and lower than 1.5m, and the brace across the width of scaffold should be installed within 15m in horizontal direction at 45 degree angle. 3) The entire scaffold should be securely tied to the wall of permanent structure with uslng anchor and bolt at intervals not to exceed 6m in case of non-connection and 4.5m in case of connection in both horizontal and vertical direction. 4) The post should be installed on the sound foundation tied to lumber footing with using base plate, and standard platform plank should be produced in the factory and widely used in the construction field.

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Analysis of Computer Related Occupational Preferences of Vocational High School Students (실업계 고등학교 학생들의 컴퓨터 관련 직업선호도 분석)

  • 최은하;박병섭
    • Journal of the Korea Computer Industry Society
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    • v.2 no.12
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    • pp.1563-1572
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    • 2001
  • Information wave of 21th century industrial society being undergone a change to knowledge post-industrial society new sense of values and life require. Also, computer is interacting, and adapts spontaneously in current enemy these age by important means on information-oriented society that change rapidly and computer-aided education is essential to improve country competitive power. Grasp computer education actual conditions of vocational high school for positivity that is industrial technology that IT base knowledge information-oriented society requires in this research hereupon, and though students' profession preference wishes to supply pabulum in course education presenting improvement direction of more efficient computer-aided education through investigation, there is the purpose. In present school curriculum, satisfaction about computer connection education responded that have interest much very appeared in general high. Also, computer connection profession preference was expose that research results keep in step and prefers most Information Communication Technology (ICT) field and multi media field that is embossed newly in post-industrial society.

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THREE DIMENSIONAL FINITE ELEMENT ANALYSIS OF INTERNALLY CONNECTED IMPLANT SYSTEMS (내부연결방식 임플랜트 시스템의 삼차원 유한요소법적 연구)

  • Kim Yu-Lee;Cho Hye-Won;Lee Jai-Bong
    • The Journal of Korean Academy of Prosthodontics
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    • v.44 no.1
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    • pp.85-102
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    • 2006
  • Statement of problem: Currently, there are some 20 different geometric variations in implant/abutment interface available. The geometry is important because it is one of the primary determinants of joint strength, joint stability, locational and rotational stability. Purpose: As the effects of the various implant-abutment connections and the prosthesis height variation on stress distribution are not yet examined this study is to focus on the different types of implant-abutment connection and the prosthesis height using three dimensional finite element analysis. Material and method. The models were constructed with ITI, 3i TG, Bicon, Frialit-2 fixtures and solid abutment, TG post, Bicon post, EstheticBase abutment respectively. And the super structures were constructed as mandibular second premolar shapes with 8.5 mm, 11 mm, 13.5 mm of crown height. In each model, 244 N of vertical load and 244 N of $30^{\circ}$ oblique load were placed on the central pit of an occlusal surface. von Mises stresses were recorded and compared in the crowns, abutments, fixtures. Results: 1. Under the oblique loading, von Mises stresses were larger in the crown, abutment, fixture compared to the vertical loading condition. 2. The stresses were increased proportionally to the crown height under oblique loading but showed little differences with three different crown heights under vertical loading. 3. In the crown, the highest stress areas were loading points under vertical loading, and the finish lines under oblique loading. 4. Under the oblique loading, the higher stresses were located in the fixture/abutment interface of the Bicon and Frialit-2 systems compared to the ITI and TG systems. Conclusions: The stress distribution patterns of each implant-abutment system had difference among them and adequate crown height/implant ratio was important to reduce the stresses around the implants.

Moment Resistance Performance of Each Joint for Post-Beam Frame Structure (기둥-보 뼈대구조를 위한 각부 접합부의 모멘트저항성능)

  • Park, Joo-Saeng;Hwang, Kweon-Hwan
    • Journal of the Korean Wood Science and Technology
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    • v.39 no.1
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    • pp.8-14
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    • 2011
  • Japanese larch glulam was used as structural members to develop a modern engineered wood jointing system using traditional post and beam structure. For the connections comprised of traditional joining and drift-pins, structural members are processed at a pre-cut factory. As a basic study to examine and increase the whole shear performance of portal frame, pin withdrawal test and moment resistance tests were conducted on each connection. The post and beam members with specified connectors showed good bearing performance in the wood members' joining system, column-base and beam-end. Moment rigidity was a bit better in a joint with higher slenderness ratio of drift-pin, but moment resistance performances, yield moment and maximum moment, were excellent in smaller one.

A Study of the Space Composition and Formation of Roo Bridges in Southern China (중국 남방지역 누교(樓橋)의 공간구성과 조형성에 관한 연구)

  • Jang, Hun-Duk
    • Journal of architectural history
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    • v.16 no.3
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    • pp.7-20
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    • 2007
  • A bridge is a space used as a passage. This space should be functional, solid, and beautiful. Since the beginning of human life, bridge architecture has given importance to function as a connection from one place to another. Stepping stones in the stream were the connections between divided spaces in the agricultural life, the bridge on the entrances of a town was the place for separation, expectation, and communication for people gathering around the community. Southern Chinese provinces such as Zhejiang, Hunan, Yunnan, and Guizhon is famous for it's spectacular scenary, and tribes like the 'Miao' and 'Dong' live in a cooperate community. The 'Dong' tribe is one of the 'Yue' genealogy where the people have settled down in this place in the days of 'Qin Shi Huang(Qin dynasty)'. As the population of the 'Dong' tribe growed, they used a bridge to connect town to town. The scale became larger with additional design, giving splendid achievement to bridge architecture. The 'Fungyu bridge' in Tongdao and 'Chungyang bridge' in Sanjiang are some fine examples. The Fungyu bridge could be defined as a bridge which blocks wind and rain, this has the same function as the lounge bridge in Taishun located in southern Zhejiang province. In Taishun, 5 minority races such as the 'Dong' and 'Miao' people have been living together as a clan society for centuries on mountains as high as 1000m following their own tradition. The 'Xiliu river' flowing thorough has a variety of bridges remaining in it's original form, and it is recently known as a museum of ancient bridges. The formation of the bridges in Tongdao and Taishun shows that it is different with the arch and straight bridges remaining in Korea. In this study, it is readjusting the base data, showing plan characteristics and describing the construction of the wooden structure above the bridge post.

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