• 제목/요약/키워드: Biaxial Loading

검색결과 132건 처리시간 0.021초

양축 면내 압축하중 하의 이중판보강 선박판부재의 설계시스템 구축 (Development of Ship Plate Member Design System Reinforced by Doubler Plate Subjected to Biaxial In-plane Compressive Load)

  • 함주혁
    • 한국해양공학회지
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    • 제30권4호
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    • pp.294-302
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    • 2016
  • Because of the importance of steel material saving and rational ship structural design due to the rapid increase in steel prices, a ship structural design system was developed for plate members reinforced by doubler plates subjected to biaxial in-plane compressive loads. This paper mainly emphasizes the design system improvement and upgrade according to the change in the in-plane loading condition of the doubler plate from the single load discussed in a previous paper to the biaxial in-plane compressive load discussed in this paper. A direct design process by a structural designer was added to this developed optimized system to increase the design efficiency and provide a way of directly inserting a designer's decisions into the design system process. As the second stage of preliminary steps of doubler design system development, design formulas subjected to these biaxial loads used in the doubler plate design system were suggested. Based on the introduction of influence coefficients $K_t_c$, $K_t_d$, $K_b_d$ and $K_a_d$ based on the variations in the doubler length, breadth, doubler thickness, and average corrosion thickness of the main plate reinforced by the doubler plate, respectively, the design formulas for the equivalent plate thickness of the main plate reinforced by the doubler plate were also developed, and a hybrid design system using these formulas was suggested for the doubler plate of a ship structure subjected to a biaxial in-plane compressive load. Using this developed design system for a main plate reinforced by a doubler plate was expected to result in a more rational reinforced doubler plate design considering the efficient reinforcement of ship plate members subjected to these biaxial loads. Additionally, a more detail structural analysis through local strength evaluations will be performed to verify the efficiency of the optimum structural design for a plate member reinforced by a doubler plate.

A Study on Mixed Mode Crack Initiation under Static Loading Condition

  • Koo, Jea-Mean
    • International Journal of Safety
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    • 제2권1호
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    • pp.1-6
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    • 2003
  • In this paper, several different fracture criteria using the Eftis and Subramanian's stress solutions [1] are compared with the printed experimental results under different loading conditions. The analytical results of using the solution with non-singular term show better than without non-singular in comparison with the experimental data. And maximum tangential stress criterion (MTS) and maximum tangential strain energy density criterion (MTSE) can get useful results for several loading conditions.

탄소섬유 건직물의 일방향 편향 인장실험과 이축 인장실험 (Bias Extension and Biaxial Tests for Carbon Dry Fabrics)

  • 장승환;전성식
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2003년도 추계학술발표대회 논문집
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    • pp.99-102
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    • 2003
  • This paper aims to observe the micro-mechanical behaviour of tow geometry during deformation of dry woven carbon-fiber fabric. With the increment of shear angle fabric experiences 'lock-up'phenomenon. In this paper, deformation of micro-mechanical parameters such as tow interval, change in tow amplitude and wavelength are investigated. To observe the micro-deformation of the fabric structure, appropriate specimens from bias extension and biaxial tests are sectioned and observed under the microscope. It was found that different loading conditions cause geometric deferences in the tow architecture.

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이축인장하중을 받는 철근콘크리트 패널의 비선형 유한요소해석 (Nonlinear FE Analysis of Reinforced Concrete Panels subjected to Biaxial Tensile Loads)

  • 이상진;이영정;전영선
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2003년도 봄 학술발표회 논문집
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    • pp.153-160
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    • 2003
  • Nonlinear finite element analysis of reinforced concrete panels subjected to biaxial tensile loads are carried out by using a 9-node assumed strain shell element. The present study mainly focuses on the performance evaluation of material models such as cracking criteria, tension stiffening model and steel model in the membrane energy dominant situation. From numerical results, the exponential form of tension stiffening model together with the use of average yield stress model for the steel embedded in the concrete performs well in the panel analysis under biaxial tensile loading condition and it produces a good agreement with experiment results. Finally, the present results are provided as a benchmark test for reinforced concrete panel structures.

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일축 및 이축압축을 받는 폴리머침투콘크리트의 응력-변형률 특성 (Stress-Strain Response of Polymer-Impregnated Concrete in Uniaxial and Biaxial Compression)

  • 변근주;이상민;노병철;이용진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1991년도 가을 학술발표회 논문집
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    • pp.93-98
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    • 1991
  • Polymer-Impregnated Concrete(PIC) can be considered composite material of concrete and polymer and has superior properties compared to conventional cement concrete, such as strength, stiffness, toughness, durability, water-proofing, chemical resistance. However, so far, the usage of PIC has been limited to repairing materials and non-structural applications, due to the lack of the design criteria and the analytical model to determine structural behavior. The objective of this study is to define the stress-strain response and strength characteristics of PIC in uniaxial and various biaxial compressive loading. On the bases of experimental results, general stress-strain relation, biaxial failure envelope and strength evaluation formular of PIC made with normal aggregate and methylmethacrylate(MMA) are proposed.

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이등방성 콘크리트 모델을 이용한 폭발하중을 받는 철근콘크리트 슬래브의 비선형 동적해석 (Non-linear Dynamic Analysis of Reinforced Concrete Slabs Subjected to Explosive Loading Using an Orthotropic Concrete Constitutive Model)

  • 이민주;곽효경
    • 한국전산구조공학회논문집
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    • 제32권6호
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    • pp.409-416
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    • 2019
  • 본 논문에서는 폭발하중을 받는 철근콘크리트 슬래브의 비선형 해석을 위한 개선된 수치 모델을 제안한다. 제안된 모델은 2축 응력 상태를 반영한 등가 강도에 의해 정의된 응력-변형률 관계를 사용하여 응력 상태를 직접 결정하는 변형률 속도 의존 이등방성 구성 모델을 다룬다. 또한, 균열 발생 후 콘크리트와 철근 사이의 부착 슬립이 점차 확대되어 소성힌지 영역으로 집중된다. 2축 응력 상태에서 콘크리트의 균열 방향은 주응력 방향에 따라 달라지므로 이를 고려한 부착 슬립 모델을 해석에 도입하였다. 해석 모델의 검증을 위해 수치해석과 실험결과의 상관관계 연구(correlation studies)가 수행되었다. 해석결과는 재료모델의 2축 거동과 부착 슬립의 영향을 고려하는 것이 해석결과의 정확성 향상에 중요함을 보여주며 제안된 해석 모델이 철근콘크리트 슬래브 부재의 폭발해석에 효과적으로 사용될 수 있음을 확인하였다.

A review of experimental and numerical studies on crack growth behaviour in rocks with pre-existing flaws

  • G. Sivakumar;V.B. Maji
    • Geomechanics and Engineering
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    • 제35권4호
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    • pp.333-366
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    • 2023
  • Rock as a mass generally exhibits discontinuities, commonly witnessed in rock slopes and underground structures like tunnels, rock pillars etc. When these discontinuities experiences loading, a new crack emerges from them which later propagates to a macro scale level of failure. The failure pattern is often influenced by the nature of discontinuity, geometry and loading conditions. The study of crack growth in rocks, namely its initiation and propagation, plays an important role in defining the true strength of rock and corresponding failure patterns. Many researchers have considered the length of the discontinuity to be fully persistent on rock or rock-like specimens by both experimental and numerical methods. However, only during recent decades, there has been a substantial growth in research interest with non-persistent discontinuities where the crack growth and its propagation phenomenon were found to be much more complex than persistent ones. The non-persistence fractures surface is generally considered to be open and closed. Compared to open flaws, there is a difference in crack growth behaviour in closed or narrow flaws due to the effect of surface closure between them. The present paper reviews the literature that has contributed towards studying the crack growth behaviour and its failure characteristics on both open and narrow flaws subjected to uniaxial and biaxial compression loading conditions.

이축방향 교번반복하중을 받는 구형 철근콘크리트교각의 거동특성 시험 (Bi-Axial Alternate Cyclic Loading Test of Rectangular Reinforced Concrete Columns)

  • 김재관;김익현;이재호;김남식
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2001년도 춘계학술대회 논문집
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    • pp.323-328
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    • 2001
  • The behavior of bridge column under multi-directional loading as well as uni-directional loading need to be studied because bridge columns will be subjected to the multi-directional cyclic loading during a strong earthquake. To evaluate the capacity of columns, uni-axial cyclic loading tests and bi-axial alternate cyclic loading tests were carried out. The number of cycles of alternate bi-axial loading were determined considering the ratio of natural frequencies in two orthogonal directions. From the test results, strength degradation and ductility reduction were observed in biaxial loading conditions. Their rates were found to be more rapid in the loading pattern that was determined considering the different natural frequencies.

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Shear stresses below the rectangular foundations subjected to biaxial bending

  • Dagdeviren, Ugur
    • Geomechanics and Engineering
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    • 제10권2호
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    • pp.189-205
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    • 2016
  • Soils are subjected to additional stresses due to the loads transferred by the foundations of the buildings. The distribution of stress in soil has great importance in geotechnical engineering projects such as stress, settlement and liquefaction analyses. The purpose of this study is to examine the shear stresses on horizontal plane below the rectangular foundations subjected to biaxial bending on an elastic soil. In this study, closed-form analytical solutions for shear stresses in x and y directions were obtained from Boussinesq's stress equations. The expressions of analytical solutions were simplified by defining the shear stress influence values ($I_1$, $I_2$, $I_3$), and solution charts were presented for obtaining these values. For some special loading conditions, the expressions for shear stresses in the soil below the corners of a rectangular foundation were also given. In addition, a computer program was developed to calculate the shear stress increment at any point below the rectangular foundations. A numerical example for illustrating the use of the presented solution charts was given and, finally, shear stress isobars were obtained for the same example by a developed computer program. The shear stress expressions obtained in this work can be used to determine monotonic and cyclic behavior of soils below rectangular foundations subjected to biaxial bending.