• 제목/요약/키워드: Strength Assessment

검색결과 1,263건 처리시간 0.024초

外力의 效果를 고려한 熔接部의 最終强度에 대한 評價 (An Assessment on the Ultimate Strength of Welding Joint by the Effect of External Force)

  • 방한서;차용훈;오우석
    • 한국해양공학회지
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    • 제9권2호
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    • pp.20-29
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    • 1995
  • When structures are constructed by welding, structural elements are always accompained by welding residual stress and deformation. Therefore, when the rigidity and strength of the welded structures is considered, it is very important to have sufficient information about the effect of initial deflection and welding residual stress on them. In this paper, the square plates with welding residual stress under compression are dealt with; First, heat conduction and thermal elastic-plastic problems are analyzed by finite element method using 4-node isoparametric elements for assessment on the ultimate strength of welding joint. Later, the ultimate strength of welding joint is assessed by examining the effect of changed type of loading. The specimens are 500{\times}$500mm(a/b=1) and 750{\times}$500mm(a/b=1.5) rectangular plates of whichthicknesses is 9.0mm and simply supported plates getting axiul load in each direction.

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Fatigue Strength Assessment of TLP Tendon Porch Using API 2W Gr.50 Steel

  • Im, Sung-Woo;Seo, Young-Seok;Lee, Joo-Sung
    • Journal of Ship and Ocean Technology
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    • 제11권1호
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    • pp.25-35
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    • 2007
  • This paper is concerned with the fatigue strength assessment of tendon porch found which is categorized as the special structural member in TLP. Large-scale tendon porch specimens have been designed and fabricated with API 2W Gr.50 steel recently produced by POSCO. Fatigue test has been carried out for three tendon porch specimens under various load level. Fatigue strength has been evaluated based on the nominal stress range and the results are compared with the fatigue design curve of DnV RP-C203. From the present experimental study, it has been found that the porch specimens satisfy the fatigue design rule although test was carried out under the positive stress ratio. It can be, therefore, said that the API 2W steel produced by POSCO possess sufficient fatigue strength.

Evaluation of the Relationships Between Kellgren-Lawrence Radiographic Score and Knee Osteoarthritis-related Pain, Function, and Muscle Strength

  • Kim, Si-hyun;Park, Kyue-nam
    • 한국전문물리치료학회지
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    • 제26권2호
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    • pp.69-75
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    • 2019
  • Background: Knee osteoarthritis (OA) diagnosis using Kellgren-Lawrence scores is commonly used to help decision-making during assessment of the severity of OA with assessment of pain, function and muscle strength. The association between Kellgren-Lawrence scores and functional/clinical outcomes remains controversial in patients with knee OA. Objects: The purpose of this study was to examine the relationships between Kellgren-Lawrence scores and knee pain associated with OA, function during daily living and sports activities, quality of life, and knee muscle strength in patients with knee OA. Methods: We recruited 66 patients with tibiofemoral knee OA and determined knee joint Kellgren-Lawrence scores using standing anteroposterior radiographs. Self-reported knee pain, daily living function, sports/recreation function, and quality of life were measured using the knee injury and OA outcome score (KOOS). Knee extensors and flexors were assessed using a handheld dynamometer. We performed Spearman's rank correlation analyses to evaluate the relationships between Kellgren-Lawrence and KOOS scores or muscle strength. Results: Kellgren-Lawrence scores were significantly negatively correlated with KOOS scores for knee pain, daily living function, sports/recreation function, and quality of life. Statistically significant negative correlations were found between Kellgren-Lawrence scores and knee extensor strength but not flexor strength. Conclusion: Higher Kellgren-Lawrence scores were associated with more severe knee pain and lower levels of function in daily living and sports/recreation, quality of life, and knee extensor strength in patients with knee OA. Therefore, we conclude that knee OA assessment via self-reported KOOS and knee extensor strength may be a cost-effective alternative to radiological exams.

해양구조물 설계코드에 기반한 좌굴강도 평가 시스템 개발 (Development of the Buckling Strength Assessment System based on Offshore Structure Design Code)

  • 김을년
    • 대한조선학회 특별논문집
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    • 대한조선학회 2017년도 특별논문집
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    • pp.38-45
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    • 2017
  • FPSO is widely used to develop deep sea oil fields and HHI has constructed ten(10) FPSOs. During these constructions, relevant structural design criteria such as yielding, buckling, fatigue, collision and impact strength were applied to verify structural safety. To apply the buckling strength evaluation for structures, the critical buckling stresses and applied stresses of relevant panels should be calculated. The plate and stiffened panels are to be idealized, which are needed much time and efforts by designers. Therefore, program development is necessary in order to evaluate the buckling strength conveniently and accurately. In this study, the buckling strength assessment system by using offshore code, DNV-RP-C201 was developed under MSC/PATRAN, pre-post program of finite element method. Graphic user interface program is written in MSC/PATRAN PCL functions. Source program to evaluate the buckling strength is developed in FORTRAN programming languages. The developed program is verified by comparing with the results of the Nauticus Hull developed by DNV Classification Society, and applied to the marine construction project conducted by Hyundai Heavy Industries LTD.

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급성 발목 염좌에 대한 족관절의 관절가동술이 보행과 고관절 근력에 미치는 영향 (The Effect of Ankle stability exercise and Mobilization on Hip Muscle Strength and Gait in Patients with Acute Ankle Sprain)

  • 정상모;이재남;전재형
    • 대한정형도수물리치료학회지
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    • 제24권1호
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    • pp.39-46
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    • 2018
  • Background: In most human lives, 80 percent have problems with the ankle and can be solved with a treatment that is objective in proper assessment. Discrepacts in the ankle are also associated with walking patterns and affect hip and knee joints. An evaluation of hip flexion and extensor muscles was performed to check the strength of hip joints after ankle sprain patients application of arthesis. Methods: In the hospital in Bucheon, 20 outpatients who visited the hospital for treatment with ankle sprain were tested with 10 male and 10 female patients. The criteria for selection of the study subjects were randomly divided into those with joint movement techniques applied to the ankle joints and those with conservative physical therapy. Results: In applying arthrography and preservation physical therapy to patients with ankle sprain, a difference in muscle strength between hip flexion and extensor was noted in post-evaluation comparisons. There were significant differences in the assessment of walking speed and walking time between the two counties in the gait analysis assessment (p<.05). Conclusion: Studies have shown that applying arthrography to people with ankle sprain has a greater therapeutic effect than using conservative physical therapy.

화재 구조강도에 대한 신뢰성 평가방법의 정립 (Formulation of Fire Reliability Assessment Method for Structural Strength)

  • 양영순;유원선;이상엽
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2004년도 봄 학술발표회 논문집
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    • pp.161-168
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    • 2004
  • This study describes the behavior and failure probability of basic structural member in case of fire for the research of safety assessment on onshore structure. Fire safety assessment can be done by comparing fire resistance of members with fire severity of heat load For more Practical applications, the commercial structural analysis program is linked with the in-house code and gets the limiting temperature by analyzing structural strength of member with elasto-plastic analysis and large deflection analysis. AFOSM method is utilized to obtain the failure probability against the fire. The examples of rather simple structures such as beams and plates are applied to explain and verify the procedure of fire safety assessment.

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파악력 평가도구 개발모형에 관한 연구 (A Study of Hand-Grip Strength Assessment Equipment Prototype for Visual Perception)

  • 김은정;박지환
    • 대한정형도수물리치료학회지
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    • 제17권1호
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    • pp.24-28
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    • 2011
  • Background: The purpose of this study is to make a grip strength checker to make people measure their grip strength easily, based on standardized grip strength checker chart. Method: In this study, we measured right hand grip strength of 80 women residents of Deajeon (women in their 30s to 60s, 20 in each) 2 times per day for 5days in same conditions from 20th of November 2010 to 24th of November. it was measured by Jamar Hydraculic Hand Dynamometer made lately to compare with the current measuring equipment. No matter how big their hands are, their hands were fixed at second level. Measured as they sit on a chair and let their shoulders gathered and not be rotated, let their arms be 90 degree, wrist and forearm be at the middle for the first time, and took another after they took a rest, and measured the average of the two. Result: There was not a meaningful difference between the current measuring equipment and the equipment made lately (p>.05). Conclusion: It is thought that the equipment made lately can be believed. In addition, we want people to realize their own grip strength easily by this study.

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소형펀치 시험법을 이용한 Al 2024 ECAP 재료의 강도특성 평가 (Assessment of Strength Characteristics of Al 2024 ECAP Metal Using Small Punch Testing)

  • 마영화;최정우;김선화;윤기봉
    • 대한기계학회논문집A
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    • 제30권1호
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    • pp.8-17
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    • 2006
  • When subjected to severe shear deformation by ECAP, microstructure of Al2024 becomes extremely refined. To measure the strength of that, small punch(SP) testing method was adopted as a substitute for the conventional uniaxial tensile testing because the size of material processed by ECAP were limited to ${\psi}12\;mm$ in transverse direction. SP tests were performed with specimens in longitudinal and transverse directions of Al2024 ECAP metal. For comparing the strength values with those assessed by SP tests, uniaxial tensile tests were also conducted with specimens in longitudinal direction. Failure surfaces of the tested SP specimens showed that failure mode was shear deformation and Al 2024 ECAP metal has an anisotropy in strength. Thus, conventional equations proposed for assessing the strength characteristics were improper to assess those of Al2024 ECAP metal. In this paper a way of assessing the strength of Al 2024 ECAP metal was proposed and was proven to be effective.

Charts for estimating rock mass shear strength parameters

  • Wan, Ling;Wei, Zuoan;Shen, Jiayi
    • Geomechanics and Engineering
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    • 제10권3호
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    • pp.257-267
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    • 2016
  • Charts are used extensively in slope practical application to meet the need of quick assessment of rock slope design. However, Charts for estimating the shear strength of the rock mass of a slope are considerably limited. In this paper, based on the Hoek-Brown (HB) criterion which is widely used in rock slope engineering, we present charts which can be used to estimate the Mohr-Coulomb (MC) parameters angle of friction ${\phi}$ and cohesion c for given slopes. In order to present the proposed charts, we firstly present the derivation of the theoretical relationships between the MC parameters and ${\sigma}_{ci}/({\gamma}H)$ which is termed the strength ratio (SR). It is found that the values of $c/{\sigma}_{ci}$ and ${\phi}$ of a slope depend only on the magnitude of SR, regardless of the magnitude of the individual parameters ${\sigma}_{ci}$(uniaxial compressive strength), ${\gamma}$(unit weight) and H (slope height). Based on the relationships between the MC parameters and SR, charts are plotted to show the relations between the MC parameters and HB parameters. Using the proposed charts can make a rapid estimation of shear strength of rock masses directly from the HB parameters, slope geometry and rock mass properties for a given slope.

Correlation among Motor Function and Gait Velocity, and Explanatory Variable of Gait Velocity in Chronic Stroke Survivors

  • Lee, Dong Geon;Lee, Gyu Chang
    • Physical Therapy Rehabilitation Science
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    • 제11권2호
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    • pp.181-188
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    • 2022
  • Objective: The purpose of this study to investigate the correlations among the motor function, balance, and gait velocity and the strength that could explain the variation of gait velocity of chronic stroke survivors. Design: This was a cross-sectional cohort study. Methods: Thirty hemiplegic stroke survivors hospitalized in an inpatient rehabilitation center were participated. The muscle tone of ankle plantarflexor and muscle strength of ankle dorsiflexor were measured respectively with modified Ashworth scale (MAS) and hand-held dynamometer. And the motor recovery and function with Fugl-Meyer assessment (FMA), balance with Berg balance scale (BBS) and timed up and go (TUG) test were measured. Gait velocity was measured with GAITRite. The correlation among motor function, muscle tone, muscle strength, balance, and gait were analyzed. In addition, the strength of the relationship between the response (gait velocity) and the explanatory variables was analyzed. Results: The gait velocity had positive correlations with FMA, muscle strength, and BBS, and negative correlation with MAS and TUG. Regression analysis showed that TUG (𝛽=-0.829) was a major explanatory variable for gait velocity. Conclusions: Our results suggest that gait velocity had correlations with muscle strength, MAS, FMA, BBS, and TUG. The tests and measurements affecting the variation of gait velocity the greatest were TUG, followed by FMA, BBS, muscle strength, and MAS. This study shows that TUG would be a possible assessment tool to determine the variation of gait velocity in stroke rehabilitation.