• 제목/요약/키워드: Strength evaluation method

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냉연코일 수송화차 차체의 구조 강도 평가 (Structural strength evaluation of Freight Car Carbody for transportation of cold-rolled coils)

  • 권성태;김정국;서정원
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 춘계학술대회 논문집
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    • pp.775-779
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    • 2007
  • The structural strength assessment of a carbody was performed using F.E. analysis and static test to verify the structural safety of newly manufactured carbody of a freight car. The freight car for the transportation of cold-rolled coils in steel making company was designed with SS400 steel for underframe and SM490A steel for bracket. Prior to the evaluation of structural strength, commercial finite element method(FEM) software was used for the stress and structural analyses on stress distribution in a carbody of freight car. The strain gages were attached on the carbody based on the FEM results. The actual vertical loading test and horizontal compression loading test were conducted, and the stress and displacement were obtained. Finally, the structural strength of carbody was evaluated by using a engineering techniques.

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파괴기구에 근거한 역 T형 합성지하벽의 강도평가 (Strength Evaluation of Inverted T-shaped Composite Basement Wall Based on Failure Mechanisms)

  • 박지환;서수연;이리형
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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    • pp.415-420
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    • 2003
  • This Study is performed to analyze the behavior of inverted T-shaped Composite Basement Wall(CBW). For this, it is purposed to analyze the failure mechanisms of inverted T-shaped composite basement wall and propose the method of evaluating strength for design. The failure mechanisms would be devided into 4 type mechanisms from previous experimental results, that is hanger failure, punching shear failure, flexural failure and the buckling of H-pile. A strength evaluation procedure for CBW is induced by analyzing respective failure mechanism. Then, the strength for actual structure consisted of inverted T-shaped composite basement wall was evaluated and the expected failure mechanism was determined.

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동적무기력계수에 의한 고장력강의 동적.충격강도 특성 평가 (The Estimation of Dynamic/Impact Strength Characteristics of High Tensile Steel by Dynamic Lethargy Coefficient)

  • 송준혁;박정민;채희창;강희용;양성모
    • 한국자동차공학회논문집
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    • 제10권2호
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    • pp.96-100
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    • 2002
  • The purpose of this paper is presented a rational method of predicting dynamic/impact tensile strength of high tensile steel materials widely used fur structural material of automobiles. It is known that the ultimate strength is related with the loading speed and the Lethargy Coefficient from the tensile test. The Dynamic Lethargy Coefficient is proportional to the disorientation of the molecular structure and indicates the magnitude of defects resulting from the probability of breaking the bonds responsible for its strength. The coefficient is obtained from the simple tensile test such as failure time and stresses at fracture. These factors not only affect the static strength but also have a great influence on the dynamic/impact characteristics of the joist and the adjacent structures. This strength is used to analyze the failure life prediction of mechanical system by virtue of its material fracture. The impact tensile test is performed to evaluate the life parameters due to loading speed with the proposed method. Also the evaluation of the dynamic/impact effect on the material tensile strength characteristics is compared with the result of Campbell-Cooper equation to verify the proposed method.

질화규소/금속 접합재에 대한 혼합모드의 파괴기준 및 파면해석 (Analysis of Fracture Surface and Fracture Criterion of Mixed Mode is $Si_{3}N_{4}$ Metal Bonded Joints)

  • 정남용
    • 한국생산제조학회지
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    • 제8권2호
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    • pp.86-93
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    • 1999
  • Ceramic/metal bonded joints have led to increasing use of structural materials such as automobiles and heat engines. A method of strength evaluation focussing on fracture criterion of mixed mode was investigated in {{{{ {Si }_{3 } {N }_{4 } }}}}/metal bonded joint, Also Fracture toughness tests of {{{{ {Si }_{3 } {N }_{4 } }}}}/metal bonded joints with an interface crack were carried out and the stress intensity factors of these joints were analyzed by boundary element method. Form the results the fracture criterion and method of strength evaluation by the fracture toughness were proposed in {{{{ {Si }_{3 } {N }_{4 } }}}}/Metal bonded joints

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신소재 금형펀치의 이종재 마찰용접 개발과 AE품질평가를 위한 연구 (Friction Welding of Dissimilar Press Punch Materials and Its Evaluation by AE)

  • 오세규;박일동;이원석
    • Journal of Welding and Joining
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    • 제15권2호
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    • pp.43-53
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    • 1997
  • The complete joining method for dissimilar press punch materials and its real-time evaluation method is not available at present. Brazing method has been used for joining them, but it is known that the welded joint by the brazing has the lower bonding efficiency and reliability than the diffusion welding. The friction welding with a diffusion mechanism in bonding was applied in this study. This work was carried out to determine the proper friction welding conditions and to analyze mechanical properties of friction welded joints of sintered carbide tool materials (SKNM50 for the blade part of press punch) to alloy steel (SCM440 for the shank part of press punch) using aluminum (A6061 for the interlayer material) as an insert material between the sintered carbide tool materials and the alloy steel. In addition, acoustic emission test was carried out during friction welding to evaluate the weld quality.

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이종접합 계면균열의 파괴기준에 대한 원공의 영향 (Influence of Circular Hole for Fracture Criteria of Interface Crack in Bonded Dissimilar Materials)

  • 정남용
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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    • pp.301-306
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    • 1999
  • Application of bonded dissimilar materials in various industries are increasing. When these materials are used in structures, it needs to investigate strength evaluation applying fracture mechanics. Al/Epoxy bonded dissimilar materials with an interface crack and an interface crack emanating from an edge semicircular hole were prepared for the static tests so that experiment of fracture toughness were carried out. Stress intensity factors of interface cracks in bonded dissimilar materials were computed with boundary element method(BEM) and the fracture criteria of mixed mode crack were analyzed. From the results, the fracture criteria and the method of strength evaluation by the fracture toughness in Al/ Epoxy bonded dissimilar materials were proposed.

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접착이음의 계면덧살에 대한 응력특이성 해석 (Analysis of Stress Singularity for the Excess Adhesive of Interface in Adhesively Bonded Joint)

  • 정남용;박철희
    • 한국생산제조학회지
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    • 제21권3호
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    • pp.439-445
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    • 2012
  • The stress singularity for the excess adhesive on interface of adhesively bonded joint was investigated by using the 2-dimensional elastic boundary element method (BEM). To establish a reasonable strength evaluation method and a fracture criterion for the excess adhesive of interface in adhesively bonded joint, it is necessary to evaluate fracture parameters with various bonding conditions. Under the variations of adhesively bonded thickness (h) and diameter (d) for the excess adhesive, a stress analysis was performed, and from the results, the stress singularity index (${\lambda}$) and the stress singularity factor (${\Gamma}$) were calculated. The variations have a great influences on the stress singularity for the excess adhesive of interface in adhesively bonded joint, and the ${\Gamma}$ is reduced as the "h" and "d" increase.

재봉사의 가봉성 평가 -재봉사의 사절을 중심으로- (The Evaluation of Sewability for Sewing Threads -In Relation to the Breakage of Sewing Threads During Sewing Operation-)

  • 장정대
    • 한국의류산업학회지
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    • 제1권2호
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    • pp.154-159
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    • 1999
  • In this study, for different test methods of the performance of sewing threads were used to evaluate the sewability of 10 different industrial threads. Sewability evaluations related to the breakage of thread during sewing operation were investigated by seam length and fabric thickness method (Test 1), thread tension method (Test 2), strength retention method (Test 3), and backward sewing method(Test 4), and discussed. Two of the methods, Test 1 and Test 2, simulated very harsh sewing conditions which each thread could accept as an evaluation of its sewability. Core spun thread ranked with the best sewability generally and followed by air jet textured (ATY) thread. Spun thread was superior to the filament thread in sewing thread type. In general, there was a high degree of correlation in the results of Test 1 and Test 2. The order of sewing thread by sewability test 1 was polyester spun thread, cotton thread, and p/c core spun thread. The order of sewing thread by test 2 was polyester spun thread, and p/c core spun thread. Cotton threads and cotton blended threads performed better in Test 3, and ATY threads and core spun threads in Test 4.

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철근 콘크리트 기둥의 2축휨 강도에 영향을 미치는 변수 고찰 (An Evaluation of Influencing Parameters on Biaxial Bending Moment Strength of Reinforced Concrete Columns)

  • 유석형;반병열;신성우
    • 한국구조물진단유지관리공학회 논문집
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    • 제7권2호
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    • pp.239-246
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    • 2003
  • In the PCA Load Contour Method, the biaxial bending design coefficient of columns(${\beta}$) is based on the equivalent rectangular stress block (RSB). And coefficient of ${\beta}$ estimates the reinforcement index to be a influencing parameter on biaxial moment strength of RC columns without considering the arbitrary condition of bar arrangement. The experimental results of high strength concrete (HSC) columns subjected to combined axial load and biaxial bending moment were compared to the analysis results of RSB method. As result, the accuracy of RSB method is still acceptable for HSC columns and, as the reinforcement is placed densely in each corner of column section, the ${\beta}$ is decreased.