• Title/Summary/Keyword: structural resistance

Search Result 2,308, Processing Time 0.026 seconds

Nail Withdrawal Resistance and Embedding Strength of Structural Wood Panels with Water Absorption (수분의 흡수에 따른 구조용 목질판넬의 인발 및 함입성능)

  • 오세창
    • Journal of the Korea Furniture Society
    • /
    • v.10 no.2
    • /
    • pp.1-8
    • /
    • 1999
  • The use of structural wood based panels like plywood, OSB in many applications involves the use of nails, and data on the performance of panel-nail connection are needed for design and comparative purpose. This study was carried out to develop basic information on nail performance(withdrawal, embedding, nailhead push through) with water absorption in plywood and OSB. In withdrawal resistance test, initial stiffness of plywood performed better than OSB in 24hr soaked condition. The soaked condition reduced average nail withdrawal resistance value about 46% (12d mail), 53%(8d nail) in OSB, 17%(12d mail), 24%(8d mail) in plywood. The nail embedding strength of plywood also performed better than that of OSB and retention value(wet strength/dry strength) yielded similar in each nail types. The nail head push through capacity of OSB was higher than that of plywood in dry condition, but equal or lower in soaked condition. Therefore, critical consideration about structural panels is required in moist applications. The average values of nail withdrawal, nail embedding strength and nail head push through resistance of tested materials meet the minimum requirement of various specification and standards.

  • PDF

Development of ELID Monitoring System and its Application to ELID Grinding of Structural Ceramics (ELID 연삭 모니터링 시스템의 개발과 구조 세라믹스 적용 사례)

  • Kwak, Tae-Soo;Kim, Gyung-Nyun;Kwak, Ihn-Sil
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.30 no.12
    • /
    • pp.1245-1251
    • /
    • 2013
  • This study has focused on development of ELID monitoring system and its application to ELID grinding of structural ceramics. ELID monitoring system was consisted of grinding equipment, ELID power supply, grinding wheel, electrode and monitoring program. It can give a real time data to check spindle grinding resistance, wheel revolution, dressing current and voltage in ELID grinding process. The performance of developed system was evaluated by applying to grinding of structural ceramics, silicon carbide and alumina. As the results of experiments, monitored data for spindle resistance and ELID dressing current was useful to check steady-state ELID grinding process. From the comparison of spindle resistance between ELID grinding and conventional grinding process according to change of depth of cut, it could be confirmed that the spindle resistance in ELID grinding was lower than conventional grinding process.

Basic Design for Earthquake Resistance of Typical Bridges (일반교량의 내진성능 확보를 위한 기본설계)

  • Kook, Seung-Kyu
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.26 no.1
    • /
    • pp.49-57
    • /
    • 2013
  • Structural elements of typical bridges are superstructure, connections, substuctures and foundations and earthquake resistance is decided with the failure mechanism formed by substuctures and connections. Therefore earthquake resistant design should be carried out in the basic design step where design strengths, e.g. design sections for structural elements are determined. The Earthquake Resistant Design Part of Korean Roadway Bridge Design Code provides two basic design procedures. The first conventional procedure applies the Code-provided response modification factors. The second new procedure is the ductility-based earthquake resistant design, where designer can determine the response modification factors. In this study, basic designs including the two design processes are carried out for a typical bridge and supplements are identified in view of providing earthquake resistance.

Experimental Study on Limiting Temperatures of Structural Beams made with Structural Steel According to Load Ratios (하중비에 따른 강재 보의 한계온도에 관한 실험적 연구)

  • Kwon, In-Kyu
    • Journal of Korean Society of Steel Construction
    • /
    • v.22 no.6
    • /
    • pp.581-588
    • /
    • 2010
  • Recently the requirements of the buildings built with structural steel were increased in terms of structural stabilities and fire resistance at severe fire conditions. To meet the building regulations of fire resistance, a fire design is needed. This is of a prescriptive method and a performance engineering based method. Recently a simple calculation method as one of performance based engineering method is very popular because of its ease for an application in building built with structural steel. But, in Korea the performance based engineering method is not allowed yet. Thus it is needed to make a guideline for the performance based engineering method. The purpose of this study is to establish the limit temperature derived from structural beams made with both a H-section and a H-section filled with concrete at the web and derived the limit temperatures from beams made with H-sections and found out that the limit temperatures from two kinds of specimens depended on the applied loads and the specimens filled with the concrete represented 3 hour fire resistance in the range of 80%, 60%, and 50% of the maximum load.

A Study on Structural Analysis of Globe Valve for LNG Carrier (LNG선박용 글로브 밸브 구조해석에 관한 연구)

  • Kim, Dong-Kyoon;Kim, Jeong-Hwan
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.31 no.8
    • /
    • pp.1013-1019
    • /
    • 2007
  • This paper is about structural analysis of globe valve for controlling cryogenic LNG's flow or stop in normal temperature. The used valve is demanded safety resistance for inner pressure and temperature variation caused by using it in cryogenic, high pressure surrounding. This study evaluates for safety resistance for inner pressure and temperature variation by heat transfer analysis in cryogenic surrounding, heat stress analysis in temperature variation and deformation analysis in high pressure.

The Parameter Study on the Characteristics of Axial Force in Turnout with Continuous Welded Rail (분기부(分岐部) 장대(長大)레일화시의 축력거동특성(軸力擧動特性) 해석(解析))

  • Kim, Doo-Hwan;Ko, Sang-Hun
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.5 no.2
    • /
    • pp.163-174
    • /
    • 2001
  • This paper is to study the characteristics of axial force behavior that operates to the part of turnout when it makes the turnout and the continuous welded rail unifying. The study is to model by using the 50kgN rail No. 15 turnout used in the domestic national railway and the UIC60 rail No. 18 turnout used in the rapid transit railway as the finite elements for analyzing the axial force behavior of the turnout by the continuous welded rail. It is to analyze the characteristics of behavior according to the change of creep resistance, ballast resistance and the change of parameter valuables of heel joint by the axial force simulation in making the continuous welded rail and then, it is to present the result. As the result of research on the parameter valuables through the analysis, it shows that the maximum axial force of turnout by the continuous welded rail are largely subordinated to the maximum resistance of heel joint and the fitting devices than the ballast resistance. Also it shows that the maximum axial force produced changes a lot according to the characteristics of creep resistance of the fitting part and the ballast resistance.

  • PDF

An innovative system to increase the longitudinal shear capacity of composite slabs

  • Simoes, Rui;Pereira, Miguel
    • Steel and Composite Structures
    • /
    • v.35 no.4
    • /
    • pp.509-525
    • /
    • 2020
  • Steel-concrete composite slabs with profiled steel sheeting are widely used in the execution of floors in steel and composite buildings. The rapid construction process, the elimination of conventional replaceable shuttering and the reduction of temporary support are, in general, considered the main advantages of this structural system. In slabs with the spans currently used, the longitudinal shear resistance commonly provided by the embossments along the steel sheet tends to be the governing design mode. This paper presents an innovative reinforcing system that increases the longitudinal shear capacity of composite slabs. The system is constituted by a set of transversal reinforcing bars crossing longitudinal stiffeners executed along the upper flanges of the steel sheet profiles. This type of reinforcement takes advantage of the high bending resistance of the composite slabs and increases the slab's ductility. Two experimental programmes were carried out: a small-scale test programme - to study the resistance provided by the reinforcing system in detail - and a full-scale test programme to test simply supported and continuous composite slabs - to assess the efficacy of the proposed reinforcing system on the global behaviour of the slabs. Based on the results of the small-scale tests, an equation to predict the resistance provided by the proposed reinforcing system was established. The present study concludes that the resistance and the ductility of composite slabs using the reinforcing system proposed here are significantly increased.

Establishment of Fire Reliability Assessment Method for Structural Strength (화재시 구조강도에 대한 신뢰성 평가방법의 정립)

  • Park, Chang-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.10
    • /
    • pp.54-62
    • /
    • 2017
  • This paper describes the behavior and failure probability of the basic structural members in a fire for the fire safety assessment of offshore structures. A fire safety assessment can be accomplished by comparing the fire resistance of the members with the fire severity of the heat load due to fire. The fire severity is represented as the maximum temperature of the members using the Eurocode 1 standard fire curve and heat transfer equation. On the other hand, the fire resistance is the limiting temperature calculated by a simplified formula in the case of simple structural members. Considering the complexity of FPSOs and offshore structures, a general-purpose structural analysis program should be used and the limiting temperature obtained by analyzing the structural strength of the members through an elasto-plastic analysis with a large deflection, and compared with the maximum temperature. Also, the equality of these two methods of evaluating the fire resistance was confirmed by comparing them. Following three criteria, the strength, serviceability and stability, three failure modes, namely the first failure of a hinge, large deflection and buckling, were chosen. The failure temperature was verified for each failure mode. using the AFOSM method in the equation of the fire severity and fire resistance, thereby giving the failure probability of the member. By applying these processes to the example of a beam and plate, the behavior of the structure and failure (temperature?) of each failure mode can be determined.

A Evaluation of Fire Behavior According to Member Thickness of Precast Prestressed Hollow Core Slab of Fire Resistance Section (프리캐스트 프리스트레스트 내화단면 중공슬래브의 부재두께에 따른 화재거동평가 )

  • Yoon-Seob Boo;Kyu-Woong Bae;Sang-Min Shin
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.27 no.1
    • /
    • pp.1-8
    • /
    • 2023
  • At construction sites, interest in the production of precast materials is increasing due to off-site conditions due to changes in construction site conditions due to increased labor costs and the Act on the Punishment of Serious Accidents. In particular, the precast prestressed hollow slab has a hollow shape in the cross section, so structural performance is secured by reducing weight and controlling deflection through stranded wires. With the application of structural standards, the urgency of securing fire resistance performance is emerging. In this study, a fire-resistance cross section was developed by reducing the concrete filling rate in the cross section and improving the upper and lower flange shapes by optimizing the hollow shape in the cross section of the slab to have the same or better structural performance and economic efficiency compared to the existing hollow slab. The PC hollow slab to which this was applied was subjected to a two-hour fire resistance test using the cross-sectional thickness as a variable, and as a result of the test, fire resistance performance (load bearing capacity, heat shielding property, flame retardance property) was secured. Based on the experimental results, it is determined that fire resistance modeling can be established through numerical analysis simulation, and prediction of fire resistance analysis is possible according to the change of the cross-sectional shape in the future.

A Study on Acceptance and Resistance of Smart TVs

  • Lee, Sung-Joon
    • International Journal of Contents
    • /
    • v.8 no.3
    • /
    • pp.12-19
    • /
    • 2012
  • This study investigated what factors affect consumers' decision making concerning the adoption of smart TVs. For this purpose, the integrated adoption model that consists of six major constructs from the diffusion of innovation theory (DIT), the technology acceptance model (TAM), and the model of innovation resistance(MIR) was employed. To collect data, an online survey was used. Data collected were analyzed with the structural equation model (SEM). Findings showed that the innovativeness has a positive influence on the both of perceived usefulness and perceived ease of use. It was also shown that both of perceived usefulness and perceived ease of use affect the intention to use smart TVs in a positive way. The innovation resistance has a negative influence on the intention to use. The mediating role of the innovation resistance was also found. The implications of these results are discussed.