• Title/Summary/Keyword: Post-structural

Search Result 1,259, Processing Time 0.022 seconds

Shear Performance of Hybrid Post and Beam Wall System Infilled with Structural Insulation Panel (SIP)

  • Shim, Kug-Bo;Hwang, Kweon-Hwan;Park, Joo-Saeng;Park, Moon-Jae
    • Journal of the Korean Wood Science and Technology
    • /
    • v.38 no.5
    • /
    • pp.405-413
    • /
    • 2010
  • A hybrid post and beam shear wall system with structural insulation panel (SIP) infill was developed as a part of a green home 'Han-green' project through post and beam construction for contemporary life style. This project is on-going at the Korea Forest Research Institute to develop a new building system which improves Korean traditional wet-type building system and stimulates industrialized wood construction practice with pre-cut system. Compared to the traditional wet-type infill wall components, the hybrid wall system has benefits, such as, higher structural capacity, better thermal insulation performance, and shorter construction term due to the dry-type construction. To build up the hybrid wall system, in previous, SIP infill wall components can be manufactured at factory, and then inserted and nailed with helically threaded nails into the post and beam members at site. Shear performance of the hybrid wall system was evaluated through horizontal shear tests. The SIP hybrid wall system showed higher maximum shear strength, initial stiffness, ductility, yield strength, specified strength, and the specified allowable strength than those of post and beam with light-frame wall system. In addition to this, the hybrid wall system can provide speedy construction and structural and functional advantages including energy efficiency in the building system.

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
    • /
    • v.33 no.6
    • /
    • pp.427-435
    • /
    • 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.

Recent Progress of Structural Biology of tRNA Processing and Modification

  • Nakanishi, Kotaro;Nureki, Osamu
    • Molecules and Cells
    • /
    • v.19 no.2
    • /
    • pp.157-166
    • /
    • 2005
  • Transfer RNA (tRNA) is a key molecule to decode the genetic information on mRNA to amino aicds (protein), in a ribosome. For tRNA to fulfill its adopter function, tRNA should be processed into the standard length, and be post-transcriptionally modified. This modification step is essential for the tRNA to maintain the canonical L-shaped structure, which is required for the decoding function of tRNA. Otherwise, it has recently been proposed that modification procedure itself contributes to the RNA (re)folding, where the modification enzymes function as a kind of RNA chaperones. Recent genome analyses and post-genome (proteomics and transcriptomics) analyses have identified genes involved in the tRNA processings and modifications. Furthermore, post-genomic structural analysis has elucidated the structural basis for the tRNA maturation mechanism. In this paper, the recent progress of the structural biology of the tRNA processing and modification is reviewed.

Evaluating seismic demands for segmental columns with low energy dissipation capacity

  • Nikbakht, Ehsan;Rashid, Khalim;Mohseni, Iman;Hejazi, Farzad
    • Earthquakes and Structures
    • /
    • v.8 no.6
    • /
    • pp.1277-1297
    • /
    • 2015
  • Post-tensioned precast segmental bridge columns have shown high level of strength and ductility, and low residual displacement, which makes them suffer minor damage after earthquake loading; however, there is still lack of confidence on their lateral response against severe seismic loading due in part to their low energy dissipation capacity. This study investigates the influence of major design factors such as post-tensioning force level, strands position, columns aspect ratio, steel jacket and mild steel ratio on seismic performance of self-centring segmental bridge columns in terms of lateral strength, residual displacement and lateral peak displacement. Seismic analyses show that increasing the continuous mild steel ratio improves the lateral peak displacement of the self-centring columns at different levels of post-tensioning (PT) forces. Such an increase in steel ratio reduces the residual drift in segmental columns with higher aspect ratio more considerably. Suggestions are proposed for the design of self-centring segmental columns with various aspect ratios at different target drifts.

A Study on the Post-buckling Behaviour of Single-layer Domes exposed to Fire (화재에 노출된 단층 돔의 후좌굴 거동에 관한 연구)

  • Lee, Sang-Jin;Bae, Jungeun
    • Journal of the Architectural Institute of Korea Structure & Construction
    • /
    • v.35 no.8
    • /
    • pp.139-148
    • /
    • 2019
  • The lightweight structures such as domes are particularly vulnerable when it has been subjected to high temperature induced by the fire. It is therefore crucial to predict the possible instability path of structures exposed to the fire in structural design process. In this study, the instabilities of single-layer domes is investigated by using finite element technologies with the consideration of high temperature. The material properties of members under high temperature are considered by using the reduction factors which is provided in Eurocodes 3. Some damage patterns are assumed with use of a structural unit which is symmetric in radial direction. For numerical evaluations, the geometrically nonlinear truss element is implemented and the arch-length control method is employed to trace the post-buckling behaviour of domes. From numerical results, it is found to be that a significant change of post-buckling behaviour is detected in dome structures when structural members are exposed to the fire.

Seismic Reliability Assessment of Mid- and High-rise Post-tensioned CLT Shear Wall Structures

  • Sun, Xiaofeng;Li, Zheng;He, Minjuan
    • International Journal of High-Rise Buildings
    • /
    • v.9 no.2
    • /
    • pp.175-185
    • /
    • 2020
  • Currently, few studies have been conducted to comprehend the seismic reliability of post-tensioned (PT) CLT shear wall structures, due to the complexity of this kind of structural system as well as due to lack of a reliable structural model. In this paper, a set of 4-, 8-, 12-, and 16-storey benchmark PT CLT shear wall structures (PT-CLTstrs) were designed using the direct displacement-based design method, and their calibrated structural models were developed. The seismic reliability of each PT-CLTstr was assessed based on the fragility analysis and based on the response surface method (RSM), respectively. The fragility-based reliability index and the RSM-based reliability index were then compared, for each PT-CLTstr and for each seismic hazard level. Results show that the RSM-based reliabilities are slightly less than the fragility-based reliabilities. Overall, both the RSM and the fragility-based reliability method can be used as efficient approaches for assessing the seismic reliabilities of the PT-CLTstrs. For these studied mid- and high-rise benchmark PT-CLTstrs, following their fragility-based reliabilities, the 8-storey PT-CLTstr is subjected to the least seismic vulnerability; while, following their RSM-based reliabilities, the 4-storey PT-CLTstr is subjected to the least seismic vulnerability

Seismic response of complex 3D steel buildings with welded and post-tensioned connections

  • Reyes-Salazar, Alfredo;Ruiz, Sonia E.;Bojorquez, Eden;Bojorquez, Juan;Llanes-Tizoc, Mario D.
    • Earthquakes and Structures
    • /
    • v.11 no.2
    • /
    • pp.217-243
    • /
    • 2016
  • The linear and nonlinear seismic responses of steel buildings with perimeter moment resisting frames and welded connections (WC) are estimated and compared with those of buildings with post-tensioned connections (PC). Two-dimensional (2D) and three-dimensional (3D) structural representations of the buildings as well as global and local response parameters are considered. The seismic responses and structural damage of steel buildings with PC may be significantly smaller than those of the buildings with typical WC. The reasons for this are that the PC buildings dissipate more hysteretic energy and attract smaller inertia forces. The response reduction is larger for global than for local response parameters. The reduction may significantly vary from one structural representation to another. One of the main reasons for this is that the energy dissipation characteristics are quite different for the 2D and 3D models. In addition, in the case of the 3D models, the contribution of each horizontal component to the axial load on an specific column may be in phase each other during some intervals of time, but for some others they may be out of phase. It is not possible to observe this effect on the 2D structural formulation. The implication of this is that 3D structural representation should be used while estimating the effect of the PC on the structural response. Thus, steel frames with post-tensioned bolted connections are a viable option in high seismicity areas due to the fact that brittle failure is prevented and also because of their reduced response and self-centering capacity.

Pre/Post Processors for the Design of Steel Box Girder Bridges (강합성상형교 설계를 위한 전.후처리 시스템 개발)

  • 정영식;정현태
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 1998.04a
    • /
    • pp.183-190
    • /
    • 1998
  • This paper discusses the development and use of an integrated system for the design of steel box girder bridges. The system includes pre/post processors designed particularly for the ease of use by adopting GUI(Graphical User Interface). They offer convenient facilities for the management of design data and thus enable the user to draw satisfactory structural designs. In particular, ease of redesign iterations makes better structures possible in this system

  • PDF

New Approach to Integrated Structural Analysis and Design for Multistory RC/Post-Tensioned Buildings (ADAPT Edge 2012-RC/PT 다층 구조물 해석 및 설계 프로그램)

  • Aalami, Florian;Lee, Soo Heon
    • Computational Structural Engineering
    • /
    • v.25 no.4
    • /
    • pp.63-70
    • /
    • 2012
  • This article introduces ADAPT Corporation's latest software product for the integrated multistory analysis and design of concrete buildings, ADAPT Edge. Edge uniquely packages user-friendly modeling of multistory buildings, accurate gravity and lateral analysis, post-tensioning, and detailed slab and beam design, all in one software package. The benefits of Edge over traditional concrete design software are explained.

Design Evaluation of the Post-installed Anchor considering Effective Embedded Depth and Concrete Strength (유효 묻힘 깊이와 콘크리트 강도를 고려한 후설치 앵커의 설계식 평가)

  • Hur, Moo-Won;Chae, Kyoung-Hun;Won, Jae-Sik;Park, Tae-Won
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.25 no.3
    • /
    • pp.13-20
    • /
    • 2021
  • Post-installed anchor is a structural material that connects structural and non-structural members to existing concrete members. However, there are cases where rebar interception and construction error occur at the site. In that case, measures are needed to prevent performance degradation of the rear-installation anchors. In this study, in order to evaluate the performance of torsional control expandable post-installed anchors for compressive strength and effective depth of the reference concrete was tested. The results of the most commonly used tests of M10 and M20 showed that had variable coefficients within 15%, satisfying the reliability presented in KCI(2017). It was also confirmed that the depth of the buried and the strength of concrete affect the strength of the pavement. Based on the results of the existing similar studies and the results of this study, the design equation of the post-installed anchor was proposed and the results were compared with the existing design.