• Title/Summary/Keyword: fracture tests

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Diagnostic accuracy of clinical tests to rule out elbow fracture: a systematic review

  • Giorgio Breda;Gianluca De Marco;Pierfranco Cesaraccio;Paolo Pillastrini
    • Clinics in Shoulder and Elbow
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    • v.26 no.2
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    • pp.182-190
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    • 2023
  • Elbow traumas represent a relatively common condition in clinical practice. However, there is a lack of evidence regarding the most accurate tests for screening these potentially serious conditions and excluding elbow fractures. The purpose of this investigation was to analyze the literature concerning the diagnostic accuracy of clinical tests for the detection or exclusion of suspected elbow fractures. A systematic review was performed using the Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA) guidelines. Literature databases including PubMed, Cumulative Index to Nursing and Allied Health Literature, Diagnostic Test Accuracy, Cochrane Library, the Web of Science, and ScienceDirect were searched for diagnostic accuracy studies of subjects with suspected traumatic elbow fracture investigating clinical tests compared to imaging reference tests. The risk of bias in each study was assessed independently by two reviewers using the Quality Assessment of Diagnostic Accuracy Studies 2 checklist. Twelve studies (4,485 patients) were included. Three different types of index tests were extracted. In adults, these tests were very sensitive, with values up to 98.6% (95% confidence interval [CI], 95.0%-99.8%). The specificity was very variable, ranging from 24.0% (95% CI, 19.0%-30.0%) to 69.4% (95% CI, 57.3%-79.5%). The applicability of these tests was very high, while overall studies showed a medium risk of bias. Elbow full range of motion test, elbow extension test, and elbow extension and point tenderness test appear to be useful in the presence of a negative test to exclude fracture in a majority of cases. The specificity of all tests, however, does not allow us to draw useful conclusions because there was a great variability of results obtained.

A Study on the ballistic performance and fracture mode of anodized Aluminum 5052-H34 alloy laminates (알루미늄 5052-H34 합금 적층재의 방탄성능과 파괴모드에 관한 연구)

  • 손세원;김희재;박영의;홍성희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.507-512
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    • 2000
  • The ob.jective of this study is to determine fracture behaviors(penetrati0n modes) and resistance to penetration duringballistic impact of Al 5052-H34 alloy laminates and anodized Al 5052-H34 alloy laminates. Resistance to penetration is determined by $V_{50}$ ballistic limit, a statical velocity with 50% probability for complete penetration, test method. Fracture behaviors and ballistic tolerance, described by penetration modes, are respectfully observed that result from V50 test and Projectile Through Plates (PTP) test at velocities greater than $V_{50}$. PTP tests were conducted with 0" obliquity at room temperature using 5.56mm ball projectile. $V_{50}$ tests with 0" obliquity at room temperature were conducted with projectiles that were able to achieve near or complete penetration during PTP tests. Surface Hardness, resistance to penetration, and penetration modes of A1 5052-H34 alloy laminates compared to those of anodized Al 5052-H34 alloy laminates.y laminates.

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Prediction of fracture toughness for turbine rotor steels from their mechanical test results (터어빈 로우터용 강에 대한 기계적 성질로부터 파괴인성치$K_IC$예측에 관한 연구)

  • 이학문;정순호;장윤석;이치우
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.11 no.5
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    • pp.717-724
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    • 1987
  • Mechanical properties tests and fracture toughness tests of turbine rotors were performed in the wide range of temperatures, -150.deg.C-+150.deg.C, and fracture toughness values from above tests were compared with the estimated values from mechanical properties at lower and upper shelf temperatures and FATT. The relations between mechanical properties and $K_{IC}$ properties proposed by Rolfe and Begley were reviewed and confirmed through these experimental results. On the fracture surfaces of some specimens which were satisfied with the Ikeda's $K_{IC}$ criterion micro dimple zone was detected at the rear of fatigue crack zone and it was confirmed that these specimens were not satisfied with the thickness requirement of ASTM E 399.E 399.

Punching Fracture Simulations of Circular Unstiffened Steel Plates using Three-dimensional Fracture Surface (3차원 파단 변형률 평면을 이용한 비보강 원판의 펀칭 파단 시뮬레이션)

  • Park, Sung-Ju;Lee, Kangsu;Choung, Joonmo
    • Journal of Ocean Engineering and Technology
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    • v.30 no.6
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    • pp.474-483
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    • 2016
  • Accidental events such as collisions, groundings, and hydrocarbon explosions in marine structures can cause catastrophic damage. Thus, it is extremely important to predict the extent of such damage, which determines the total amount of oil spills and the residual hull girder strength. Punching fracture tests were conducted by Choung (2009b), where various sizes of indenters and circular unstiffened steel plates with different thicknesses were used to quasi-statically realize damage extents. A three-dimensional fracture strain surface was developed based on a reference (Choung et al., 2015b), where the average stress triaxiality and average normalized Lode angle were used as the parameters governing the fracture of ductile steels. In this study, new numerical analyses were performed using very fine axisymmetric elements in combination with an Abaqus user-subroutine to implement the three-dimensional fracture strain surface. Conventional numerical analyses were also conducted for the tests to identify the best fit fracture strain values by changing the fracture strains. Based on the phenomenon of the average normalized Lode angle starting out positive and then becoming slightly negative, it was inferred that the shear stress primarily dominates in determining the fractures locations, with a partial contribution from the compressive stress. It should be stated that the three-dimensional fracture surface effectively predicted at least the shear stress-dominant fracture behavior of a mild steel.

A Study on the Fracture Behavior of CFRP in Tensile and Fracture Toughness Tests by Acoustic Emission (음향방출법에 의한 탄소 섬유 복합 재료의 인장 및 파괴 인성시험시의 파괴 거동에 관한 연구)

  • Lee, Sang-Guk;Oh, Sae-Kyoo;Nam, Ki-Woo;Kim, Og-Gyun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.15 no.1
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    • pp.277-290
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    • 1995
  • The study was carried out to analyze the fracture behavior and the acoustic emission(AE) characteristics and to find the relationship among tensile strength, fracture toughness and cure pressure in owe process of the carbon fiber reinforced composites of two types, $[0^{\circ}/90^{\circ}]_{2S}$ and $[0^{\circ}\;_2/90^{\circ}\;_2]_S$. AE signals were detected during the curing process, tensile tests and fracture toughness tests by acoustic emission(AE) measurements, respectively. Tensile strengths showed that the less cure pressurizing steps and the side of $[0^{\circ}/90^{\circ}]_{2S}$ specimens had the higher strengths than those of the others. Fracture toughness by the change of test temperature showed nearly same values in the same temperature region, but the higher test temperature had the lower fracture toughness values. In order to examine the relationship between fracture behavior of CFRP in tensile and fracture toughness tests and AE signals, the post processing for AE parameters of AE data and the observations of microscope and SEM have been carried out respectively.

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The necessary number of profile lines for the analysis of concrete fracture surfaces

  • Konkol, Janusz;Prokopski, Grzegorz
    • Structural Engineering and Mechanics
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    • v.25 no.5
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    • pp.565-576
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    • 2007
  • The article describes a technique for the measurement of the level of complexity of fracture surfaces by the method of vertical sections, and a performed statistical analysis of the effect of profile lines on the fractographic and fractal parameters of fractures, i.e. the profile line development factor, $R_L$, and the fracture surface development factor, $R_S$, (as defined by the cycloid method), as well as the fractal dimension, $D_C$, (as determined by the chord method), and the fractal dimension, $D_{BC}$, (as determined by the box method). The above-mentioned parameters were determined for fracture surfaces of basalt and gravel concretes, respectively, which had previously been subjected to fracture toughness tests. The concretes were made from mixtures of a water/cement ratio ranging from 0.41 to 0.61 and with a variable fraction of coarse aggregate to fine aggregate, $C_{agg.}/F_{agg.}$, in the range from 1.5 to 3.5. Basalt and gravel aggregate of a fraction to maximum 16 mm were used to the tests. Based on the performed analysis it has been established that the necessary number of concrete fracture profile lines, which assures the reliability of obtained testing results, should amount to 12.

Influence of Biaxial Loads on Impact Fracture of High-Strength Membrane Materials

  • Kumazawa, Hisashi;Susuki, Ippei;Hasegawa, Osamu;Kasano, Hideaki
    • Advanced Composite Materials
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    • v.18 no.4
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    • pp.395-413
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    • 2009
  • Impact tests on high-strength membrane materials under biaxial loads were experimentally conducted in order to evaluate influence of biaxial loads on impact fracture of the membrane materials for the inflated applications. Cruciform specimens of the membrane materials were fabricated for applying biaxial loadings during the impact test. A steel ball was shot using a compressed nitrogen gas gun, and struck the membrane specimen. Impact tests on uniaxial strip specimens were also conducted to obtain the effect of specimen configuration and boundary condition on the impact fracture. The results of the measured crack length and the ultra-high speed photographs indicate the impact fracture properties of the membrane fabrics under biaxial loadings. Crack length due to the impact increased with applied tensile load, and the impact damages of the cruciform membrane materials under biaxial loadings were smaller than those of under uniaxial loadings. Impact fracture of the strip specimen was more severe than that of the cruciform specimen due to the difference of boundary conditions.

Change in Fracture Toughness within Heat-Affected Zone of SA-Welded 9% Ni Steel (LNG 저장탱크 내조용 9% Ni강의 SAW 용접열영향부내 파괴인성 변화 평가)

  • Jang, Jae-Il;Lee, Jeong-Seok;Lee, Baek-U;Ju, Jang-Bok;Gwon, Dong-Il;Kim, U-Sik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.3
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    • pp.528-536
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    • 2002
  • As one step for the safety performance of LNG storage tank, the change in fracture toughness within the X-grooved weld heat-affected zone (HAZ) of newly developed 9% Ni steel, which was submerged arc (SA)-welded, was investigated. Both crack initiation fracture toughness and crack arrest fracture toughness were evaluated by the crack tip opening displacement (CTOD) tests and compact crack arrest (CCA) tests. As the evaluated region approached the fusion line, each test result shorted different tendency, that is, crack initiation toughness decreased while crack arrest toughness increased. The results were discussed through the observation of the microstructural change.

Failure Mode and Fracture Behavior Evaluation of Pipes with Local Wall Thinning Subjected to Bending Load (감육배관의 굽힘하중에 의한 손상모드와 파괴거동 평가)

  • Ahn, Seok-Hwan;Nam, Ki-Woo;Kim, Seon-Jin;Kim, Jin-Hwan;Kim, Hyun-Soo;Do, Jae-Yoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.1
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    • pp.8-17
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    • 2003
  • Fracture behaviors of pipes with local wall thinning are very important for the integrity of nuclear Power Plant. In Pipes of energy Plants, sometimes, the local wall thinning may result from severe erosion-corrosion (E/C) damage. However, the effects of local wall thinning on strength and fracture behaviors of piping system were not well studied. In this paper, the monotonic bending tests were performed of full-scale carbon steel pipes with local wall thinning. A monotonic bending load was applied to straight pipe specimens by four-point loading at ambient temperature without internal pressure. From the tests, fracture behaviors and fracture strength of locally thinned pipe were manifested systematically. The observed failure modes were divided into four types; ovalization. crack initiation/growth after ovalization, local buckling and crack initiation/growth after local buckling. Also, the strength and the allowable limit of piping system with local wall thinning were evaluated.

A Study on the Fracture Toughness Characteristics of FCAW Weldment of Steel for Offshore Structures (해양 구조물용 강재 FCAW 용접부의 파괴인성 특성에 관한 연구)

  • Kang Sung-Won;Kim Myung-Hyun;Kim Yong-Bin;Shin Yong-Taek;Lee Hae-Woo
    • Journal of Welding and Joining
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    • v.22 no.6
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    • pp.57-63
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    • 2004
  • Fracture toughness is an important parameter in designing offshore structures to ensure resistance to fracture at various temperatures. In this study, a series of experiments is carried out to obtain fracture toughness values (CTOD) of API 2W Gr.50B, welded using FCAW(Flux Cored Arc Weld). In particular, a comparison of absorbed impact energy and CTOD values are made with respect to two different welding groove shapes; double-V-groove and double-bevel-groove. Charpy impact tests are performed for specimens sampled near the root gap, and CTOD tests are carried out for three point bending specimens having the notch at weld zone. While Charpy impact test result is determined to be a good qualitative measure of fracture toughness, no quantitative correspondence between impact absorbed energy and CTOD values was found. Based on the experiment, it is observed that double-V-groove welds give lower transition temperature than those of double-bevel-groove.