• Title/Summary/Keyword: 응력 분산

Search Result 275, Processing Time 0.023 seconds

Studies on Elastic Deformation by X-ray Stress Measuremtnt of WC-Co Alloy (WC-Co합금의 X선 응력측정에 의한 탄성변형거동의 연구)

  • 부명환;오세욱;광조신
    • Journal of Ocean Engineering and Technology
    • /
    • v.8 no.2
    • /
    • pp.105-114
    • /
    • 1994
  • 초경합금은 기계적 성질이 다른 WC의 분상상과 Co의 결합상으로 구성되어 있다. 만일 이합금이 거시적으로 균일하게 변형을 하면, 각 상들은 이들의 응력상태에 따라 다르게 변형될 것이다. 따라서 WC-Co 합금의 변형특성과 강화기구를 명확히 알기 위해서는 각상의 미시적 변형과 파괴기구를 검토할 필요가 있다. 본 연구에서는 시편에 굽힘하중을 가하여, X선 회절로 분산상인 WC상 및 결합상인 Co상의 X선적 탄성정수와 응력정수를 측정하였다. WC-Co합금중의 WC상과 Co상의 상응력은 WC(112)면과 CO(311)면의 회절로서 결정하였다. 그리고 이 상응력들을 복합법칙의 적용가능성에 대하여 검토하였다.

  • PDF

A Study on Punching Shear of Column-Foundation Joint Connection for Reinforced Steel Base Plate (Base Plate로 보강된 기둥-기초 접합부의 뚫림전단강도 연구)

  • Kim, Seong-Kyum;Park, Jong-Kwon;Han, Sang-Hee;Kim, Byung-Cheol;Jang, Il-Young
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.19 no.2
    • /
    • pp.1-9
    • /
    • 2015
  • In this paper, the RC column-based joint connection part carry out loading test by reinforced hollow or extended Base Plate in order to confirm that RC joint punching shear reinforcement effect of applying the Base Plate. Base Plate thickness, extension length, size, and type as the variable, Base Plate suitable for the stress distribution and shape and dimensions confirmed through experiment and then reinforcing effect was analyzed. Experimentally, vertical load transmitted to the Base Plate from column to foundation is effective to stress distribution and then, type of hollow reinforcement more efficient than a closed. Through experiment, improve performance and ductility due to reinforcement and relative to the thickness of the existing foundation reduced even showed better performance than the existing. The behavior of the reinforced specimens be able to induce from brittle to ductile. Experiment on loading to destroy performed the pattern of cracks, destruction aspect before and after reinforcement.

불연속면 조사

  • 김경수
    • Proceedings of the KSEG Conference
    • /
    • 2004.03a
    • /
    • pp.11001-11050
    • /
    • 2004
  • 불연속면 또는 단열은 암반 내의 역학적 분리면을 통칭하는 것으로서 암반 내의 작은 흠집이나 물리적으로 불균질한 곳이나 불연속면 주위에 응력이 집중되어 초래되는 변형의 결과이다. 불연속면은 정압, 지체구조적, 그리고 열적 응력 및 높은 수압에 반응하여 형성되며, 아주 미세한 것부터 대륙 규모에 걸쳐 다양한 크기로 발달한다. 불연속면은 연속체로서의 암반을 물리적으로 분리시키기 때문에 그 자체로서 역학적인 약대에 해당되고, 지하수의 유동 통로의 기능도 하기 때문에 지질공학, 지반공학 및 수리지질학 실무에서 매우 중요한 요소로 작용한다. 경제적으로 중요한 석유, 지열 및 수자원 저류체 역시 단열 암반 내에 형성된다. 불연속면은 오염물질의 이동과 분산을 제어할 뿐만 아니라 암반을 기초로 하거나 대상으로 하는 공학적 구조물과 굴착의 안정성에도 역시 영향을 미친다. (중략)

  • PDF

플로팅 구조물 주각부의 유한요소 해석

  • Song, Hwa-Cheol;Kim, Se-Cheol
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2012.10a
    • /
    • pp.282-284
    • /
    • 2012
  • 해양플랜트의 관심의 증가로 사업의 수요가 많아지고 플랜트 사업이 활발해지고 있다. 플로팅구조물의 상부구조물과 하부구조물간의 발생 할 수 있는 집중응력으로 인한 구조적인 문제를 제기하며, 이 문제를 해결할 수 있는 효율적인 전이보시스템을 제안한다. 전이보시스템이 주각부에 발생하는 집중하중을 분산시키는 효과가 있는지 유한요소 프로그램인 ABAQUS를 통해 구조해석을 수행한다.

  • PDF

Analysis on fatigue life distribution of composite materials (복합재료 피로 수명 분포에 관한 고찰)

  • 황운봉;한경섭
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.12 no.4
    • /
    • pp.790-805
    • /
    • 1988
  • Static strength and fatigue life scattering of glass fiber reinforced epoxy composite materials has been studied. Normal, lognormal, two-parameter and three-parameter Weibull distribution functions are used for strength and one-stress fatigue life distribution. The value of mean fatigue life is analysed using mean fatigue life, mean log fatigue life and expected value of 2 and 3-parameter Weibull distribution functions. Modification on non-statistical cumulative damage models is made in order to interpret the result of two-stress level fatigue life scattering. The comparison results show that 3-parameter Weibull distribution has better predictions in static strength and one-stress level fatigue life distributions. However, no advantage of 3-parameter Weibll distribution is found over 2-parameter Weibull distribution in two-stress level fatigue life predictions. It is found that two-stress level fatigue life prediction by the expanded equal rank assumption is close to the experimental data.

Influence of the length and location of implants on distal extension removable partial dentures: finite element analysis (후방연장 가철성 국소의치에서 임플란트의 길이와 위치가 응력분산에 미치는 영향)

  • Kim, Jin-Hee;Cho, Jin-Hyun;Lee, Cheong-Hee
    • Journal of Dental Rehabilitation and Applied Science
    • /
    • v.31 no.3
    • /
    • pp.186-194
    • /
    • 2015
  • Purpose: To evaluate the effects of implant location and length on stress distribution and displacement in osseointegrated-implants that were associated with mandibular distal extension removable partial dentures (DERPD). Materials and Methods: A sagittally cut model with the #33, #34 teeth and a removable partial denture of the left mandible was used. Seven models were designed with NX 9.0. Models A, B, C had implants with lengths of 11, 6, 4 mm, respectively, under the denture base of the #37 artificial tooth. Models D, E, F had implants with lengths of 11, 6, 4 mm, respectively, under the denture base of the #36 artificial tooth. Model G did not have any implants. Axial force (250 N) was loaded on #36 central fossa. The finite element analysis was performed with MSC Nastran. Von Mises stress maps were plotted to visualize the results. Results: The models of #37 implant placement showed much lower stress concentration on the surrounding bone of the implant compared with #36. The #36 implant position tended to reduce displacement more than #37. Conclusion: When an IARPD is designed, the distal positioning of implant placement has more advantages in the edentulous bone of DERPD on the prognosis of short implants and the stress distribution of edentulous alveolar bone. Using implants with longer lengths are important for stress distribution. However, Additional studies are necessary of the effects of length on implant survival.

Optimization of Design Parameters for Lock-Claws of Pneumatic Fitting Using Taguchi Method (다구찌기법을 이용한 공압피팅용 원형 판스프링의 설계변수 최적화)

  • Kwon, Tae Ha;Suh, Chang Hee;Lee, Rac Gyu;Oh, Sang Kyun;Jung, Yun-Chul;Lim, Hwan Bin
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.37 no.12
    • /
    • pp.1541-1546
    • /
    • 2013
  • The stress concentration of lock-claws, which are one of the important parts for pneumatic fitting for a flexible tube connection, was investigated by finite element simulation. In this study, the generation of the local plastic deformation was predicted when the tube was hooked up to a pneumatic fitting in order to disperse the stress concentration, and design optimization was carried out using the Taguchi method. For the optimization, the outer width, bending angle, and inner radius of the lock-claws are used as main variables. As a result, their respective contribution ratios are revealed as 81.3%, 10.9%, and 1.5%. The ratio of the total stress distribution was improved by 4% compared with the initial design of the lock-claws.

Development of Finite Element Analysis Program for the Concrete Pavement (유한 요소법에 의한 콘크리트 포장도로의 구조해석 프로그램개발)

  • 조병완
    • Computational Structural Engineering
    • /
    • v.3 no.2
    • /
    • pp.89-95
    • /
    • 1990
  • As modern industry go further, a rigid concrete pavement has been widely constructed. The load carrying capacity of the flexible asphalt pavements is brought about by a layered system, distributing the load over the subgrade, rather than by the bending action of the slab. On the other hand, the rigid pavement, because of its rigidity and high modulus of elasticity, tends to distribute the traffic load over wide subbases, and its capacity of the strength is supplied by the slab itself. Thus, it is necessary to study the structural behavior of concrete slab under the variations of temperature changes and applied traffic loads. It reguires the development of finite element analysis program for the concrete highway pavement, which provides better understanding of concrete pavement behavior and effective design data to highway engineers.

  • PDF