• Title/Summary/Keyword: gravity-load design

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Investigation of the body distribution of load pressure and virtual wear design of short pants harnesses in flying condition (플라잉 상태에서 바지형태의 하네스에 대한 하중압력 분포 측정 및 가상착의 적용)

  • Kwon, MiYeon
    • Journal of the Korea Fashion and Costume Design Association
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    • v.23 no.3
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    • pp.11-21
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    • 2021
  • Virtual reality is currently mainly used in games, but is starting to be applied as a variety of media fields, such as broadcasting and film. Virtual reality provides more fun than reality, and can provide new experiences in areas that cannot be experienced in reality due to the constraints of time, space, and environment. In particular, as the social non-contact arena has increased due to COVID-19, it is being applied to education, health, and medical industries. The contents are further expanding into design and military fields. Therefore, the purpose of this study was to observe the change in distribution of load and pressure felt by the body in the flying state while wearing a short pants harness, which are mainly used in the game and entertainment industry. In the experiment, the average pressure in the flying state was measured by attaching a pressure sensor to the back and front of a human mannequin. As a result, it was confirmed that the load concentrated on the waist in the flying state was 44 N, with a pressure of 1353 kPa. The pressure distribution was concentrated in front of the center of gravity, and was measured was at 98% by the pressure sensors, with an average pressure value of approximately 15 kPa, and a pressure value of approximately 12 kPa at the back, which was measured at 67% by the pressure sensor. The results of the load and pressure distribution measurement are presented as fundamental data to improve the wearability and comfort of harnesses in the future, and are compared to actual measured pressure values by analyzing the clothing pressure in flight through virtual wear of harnesses through the CLO 3D program.

Numerical analysis of under-designed reinforced concrete beam-column joints under cyclic loading

  • Sasmal, Saptarshi;Novak, Balthasar;Ramanjaneyulu, K.
    • Computers and Concrete
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    • v.7 no.3
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    • pp.203-220
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    • 2010
  • In the present study, exterior beam-column sub-assemblage from a regular reinforced concrete (RC) building has been considered. Two different types of beam-column sub-assemblages from existing RC building have been considered, i.e., gravity load designed ('GLD'), and seismically designed but without any ductile detailing ('NonDuctile'). Hence, both the cases represent the under-designed structure at different time frame span before the introduction of ductile detailing. For designing 'NonDuctile' structure, Eurocode and Indian Standard were considered. Non-linear finite element (FE) program has been employed for analysing the sub-assemblages under cyclic loading. FE models were developed using quadratic concrete brick elements with embedded truss elements to represent reinforcements. It has been found that the results obtained from the numerical analysis are well corroborated with that of experimental results. Using the validated numerical models, it was proposed to correlate the energy dissipation from numerical analysis to that from experimental analysis. Numerical models would be helpful in practice to evaluate the seismic performance of the critical sub-assemblages prior to design decisions. Further, using the numerical studies, performance of the sub-assemblages with variation of axial load ratios (ratio is defined by applied axial load divided by axial strength) has been studied since many researchers have brought out inconsistent observations on role of axial load in changing strength and energy dissipation under cyclic load.

Seismic Design of Structures with Knee Braces (knee brace가 설치된 구조물의 내진설계)

  • 김진구;서영일
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.09a
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    • pp.274-281
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    • 2002
  • In this study a analytical model for a structure with buckling-restrained unbonded knee-braces is proposed, and a performance-based seismic design procedure for such a system Is provided. The proposed structure system has advantage of simplifying the structural design procedure in that the hinge-connected main structural members, such as beams and columns, are designed only for gravity loads, and all the lateral seismic load is resisted by the braces. The design procedure is based on the concept of equivalent damping, and is implemented to the capacity spectrum method. Parametric study is performed with design variables such as yield stress and cross-sectional area of knee-braces to find out proper slope of the braces.

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Design of Vertically Adjustable Transition Piece of Concrete Gravity Based Substructure for Offshore Wind Turbine (수직도 조정이 가능한 콘크리트 중력식 해상풍력 지지구조물 연결부 설계)

  • Shim, WunBo;Ahn, Jin-Young;Kwak, Dong-Woo;Bae, Kyung-Tae;Zi, Goangseup
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.4
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    • pp.42-51
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    • 2018
  • Verticality problem during the installation process in offshore wind turbine substructures could degrade the safety of the whole structures. Therefore, in this paper, the design of vertically adjustable transition piece(T.P.), using a PS anchor and grout of anchor socket in concrete gravity based substructure(G.B.S.), was proposed. T.P. was designed for 5MW offshore wind trubine and can adjust up to $0.5^{\circ}$ in verticality, occurred during installation. The design plan for each members and design procedure for T.P. was proposed. Then based on the proposed design, actual design targeting sea of Jeju-island was carried out. Finally, by use of non-linear 3D Finite Element Analysis(F.E.A.), evaluation of design was performed. As a result of evaluation, by checking load transfer mechanism and stress of T.P, proposed design was considered safe up to $0.5^{\circ}$ of adjustment.

A design of parallel mechanism to improve the workspace of platform (플랫폼의 운동성을 향상시킨 병렬 기구의 설계)

  • 유재명;최기훈;김영탁
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1655-1658
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    • 2003
  • The application area of parallel mechanism is limited in spite of many advantages of that because the workspace of platform is a very small. Thus enlargement of workspace is important issue in design of parallel mechanism. In this paper a parallel mechanism design method is described using commercial simulation program. Firstly strokes of the assembled parallel mechanism's active joints are simulated from kinetic simulation mode to get required workspace, Secondly, dynamic parameters(velocity, acceleration, force, moment) are simulated for the gravity, friction and exit load. Finally, workspace of moving platform is displayed and workspace of area is simulated by motion analysis. The results of this paper will help engineer to design parallel mechanism with optimize workspace.

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복합재료 선미익 항공기 날개 하중해석

  • Han, Chang-Hwan;Kim, Eung-Tai;Ahn, Seok-Min;Kim, Jin-Won
    • Aerospace Engineering and Technology
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    • v.1 no.1
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    • pp.8-27
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    • 2002
  • In this study, the load analysis of a composite canard aircraft is performed numerically. Excel visual basic program for PC is used to calculate aerodynamic coefficients, loads and moments etc.. The basic data required for the load analysis such as aircraft configuration and dimension, parts and its weight and coordinate etc. are obtained from Catia modeling, measurement or material density. Aircraft weight, center of gravity, inertia moment, structural design speeds, wing load distribution, forces and moments are evaluated by using these data. V-n diagram is also represented for selecting critical loads applied to the wing and fuselage. The V-n diagram is investigated to decide the flight envelope of canard aircraft for design speed VA, VC, VD and load factor +3.8G, -1.52G at maximum weight of 2,573 lbs and sea level. In the future, the results of the wing and fuselage load analysis is to represented by using selected critical loads.

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Lattice Shear Reinforcement for Earthquake-Resistance of Slab-Column Connection. (슬래브-기둥 접합부의 내진성능을 위한 래티스 전단보강)

  • Kim, You-Ni;Park, Hong-Gun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05a
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    • pp.26-29
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    • 2006
  • A flat plate-column connection is susceptible to brittle punching shear failure, which may result in the necessity of shear reinforcement. In present study, experimental tests were performed to study the capacity of slab-column connections strengthened with lattice, stud rail, shear band and stirrup under gravity and cyclic lateral load. Among them, the capacity of the specimens with lattice are superior to the others due to the truss action of the lattice bars and dowel action of the longitudinal bars as well as the shear resistance of the web re-bar. On the other hand, the strengths of the specimens with stud rail, shear band and stirrup are lower than the estimated strength by the ACI, therefore design formulas of the ACI are needed to revise.

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Key Technologies for Super Tall Building Construction: Lotte World Tower

  • Kim, Gyu Dong;Lee, Joo Ho
    • International Journal of High-Rise Buildings
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    • v.5 no.3
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    • pp.205-211
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    • 2016
  • This paper addresses the key technologies for supertall building construction based on the Lotte World Tower project in Korea. First, the mega-mat foundation construction technologies are shown, including ultra-low heat concrete, heat of hydration control programs, and the logistics plan. Then, high strength concrete technologies of 50~80 MPa are introduced and discussed within the context of the highest pumping record in Korea at 514.25 meters. Structural design concepts of gravity load and lateral force resistance systems are introduced, along with surveying systems using GNSS and temporary installation plans of special heavy equipment like tower cranes, hoists, and high pressure concrete pumps. If it is possible to coordinate these key technologies and others, optimizing for the building's design and construction, supertall building construction can be successfully completed.

Soil-pile interaction effects in wharf structures under lateral loads

  • Doran, Bilge;Seckin, Aytug
    • Structural Engineering and Mechanics
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    • v.51 no.2
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    • pp.267-276
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    • 2014
  • Wharfs are essential to shipping and support very large gravity loads on both a short-term and long-term basis which cause quite large seismic internal forces. Therefore, these structures are vulnerable to seismic activities. As they are supported on vertical and/or batter piles, soil-pile interaction effects under earthquake events have a great importance in seismic resistance which is not yet fully understood. Seismic design codes have become more stringent and suggest the use of new design methods, such as Performance Based Design principles. According to Turkish Code for Coastal and Port Structures (TCCS 2008), the interaction between soil and pile should somehow be considered in the nonlinear analysis in an accurate manner. This study aims to explore the lateral load carrying capacity of recently designed wharf structures considering soil-pile interaction effects for different soil conditions. For this purpose, nonlinear structure analysis according to TCCS (2008) has been performed comparing simplified and detailed modeling results.

Prop-blade Cross Section Design for QTP-UAV (쿼드 틸트 프롭로터 무인기용 프롭-블레이드 단면 설계)

  • Kim, Taejoo;Cho, Jin Yeon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.10
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    • pp.845-855
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    • 2018
  • Cross section design of a prop-blade is carried out for VTOL(Vertical Takeoff and Landing) Quad Tilt Prop-rotor UAV with a maximum takeoff weight of 55 kg and a maximum cruising speed of 180 km/h. Design procedure for cross section design is established and design requirements for prop-blade are identified. Through the procedure, cross section design is carried out to meet the identified requirements. Main design factors including stiffness, weight per unit length, and elastic axis are obtained by using a finite element section analysis program, and the design weight of the prop-blade is predicted. The obtained design factors are used along with the rotor system analysis program CAMRAD II to evaluate the dynamic stability of prop-blade in operating environment. In addition, the prop-blade load is obtained by CAMRAD II software, and it is used to verify the safety of the prop-blade structure. If the design results are not satisfactory, design changes are made in an iterative manner until the results satisfy the design requirements.