• Title, Summary, Keyword: Deformed angle

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Effects of Taping Therapy on the Deformed Angle of the Foot and Pain in Hallux Valgus Patients (테이핑요법이 무지외반증 환자의 발 변형 각도와 통증에 미치는 효과)

  • 전미양;정현철;정미숙;이영자;김정옥;이성태;임난영
    • Journal of Korean Academy of Nursing
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    • v.34 no.5
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    • pp.685-692
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    • 2004
  • Purpose: This study was to examine the effects of Taping therapy on the deformed angle of the foot and pain in hallux valgus patients. Method: The subjects were 24 feet from 15 patients who were diagnosed withhallus valgus at the orthopedic department of K University Hospital in Seoul. Taping therapy was conducted 15 times overall during a four-week period. Data was analyzed using descriptive statistics and t-test. Result: The deformed angle of the foot of the hallus valgus patients significantly improved from 21.95(4.38) to 18.75(4.80) after Taping therapy. Pain significantly decreased from 4.73(1.56) to 3.45(2.21) after Taping therapy. Conclusion: The result shows that Taping therapy is effective in improving the deformed angle of the foot and in decreasing pain in the hallux valgus patients.

Roles of Bearing Angle in Bond Action of Reinforcing Bars to Concrete

  • Choi OanChul
    • Journal of the Korea Concrete Institute
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    • v.16 no.5
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    • pp.719-724
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    • 2004
  • The ribs of deformed bars can split the cover concrete by wedging action or shear off the concrete in front of the ribs. As slip of deformed bars increases, the rib face angle is flattened by the crushed concrete wedge, which reduces the rib face angle to a smaller bearing angle. The roles of bearing angle are explored to simulate this observation. Analytical expressions to determine bond strength for splitting and pullout failure are derived, where the bearing angle is a key variable. As the bearing angle is reduced, splitting strength decreases and shearing strength increases. When splitting strength becomes larger than shearing strength, the concrete key is supposed to be sheared off and the bearing angle is reduced with decreasing the splitting strength. As bars slip, bearing angle decreases continually so that splitting bond strength is maintained to be less than shearing bond strength. The bearing angle is found to play a key role in controlling the bond failure and determination of bond strength of ribbed reinforcing steel in concrete structures.

A Study on Cutting Model for the Plastic Deformation on Turning Operation (선삭 가공면의 변형에 관한 절삭모델에 대한 연구)

  • Cha, Il-Nam;Kim, Yoon-Jeh
    • Journal of the Korean Society for Precision Engineering
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    • v.5 no.1
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    • pp.29-39
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    • 1988
  • Plastically deformed layer beneath metal surface machined by orthogonal cutting was evaluated in terms of residual stress, microvickers hardness, side spread, and the side strain. An attempt was made to predict the depth of layer according to machining conditions particularly tool geometry and the shear plane angle. In this paper, we employed two models concerning the sliplines. The exact model was validated by comparision of computed and measured tool force and its angle, and the model offers an upper boundary of the deformed layer to be in good agreement with the experiment.

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A New Technique Development for Measuring Plastic Strain of Precision Machined Surface (정밀가공면의 소성스트레인 측정을 위한 새로운 기법의 개발)

  • 김태영;반야풍;문상돈
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.4
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    • pp.141-147
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    • 1998
  • A plastically deformed layer in the precision machined surface affects in various forms the physical properties of machined components such as the fatigue strength, the dimensional instability, microcracks and the stress corrosion cracking. These physical properties, so called surface integrity, are very important for designing highly stressed and critically loaded components. Typical plastic strains in the precision machined surface are very difficult to measure, since they are located within a very short distance from the surface and they change very rapidly. A new way is suggested to determine the residual strain in plastically deformed materials by analyzing the plastically deformed layer after a subsequent recrystallization process. This investigation is to explore a new technique for measuring plastic strain in machining applications, and in particular, to and the effect of cutting parameters(rake angle, depth of cut, specific cutting energy), on the plastic strains and strain energy.

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Towards an Improved Understanding of Bond Behaviors

  • Choi, Oan Chul
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.239-243
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    • 2003
  • A reducing bearing angle theory for bond of ribbed reinforcing bars to concrete is proposed to simulate experimental observation. Analytical expressions to determine bond strength for splitting and pullout failure are derived, where the bearing angle is a key variable. As bearing angle is reduced, splitting strength decreases and shearing strength increases. The proposed reducing bearing angle theory is effective to simulate damage of the deformed bar-concrete interface and understand bond mechanism of ribbed reinforcing steel in concrete structures.

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A Study on the Side Collision Accident Reconstruction Using Database of Crush Test of Model Cars (모형자동차 충돌시험의 데이터베이스를 이용한 측면 충돌사고 재구성)

  • Sohn, Jeong-Hyun;Park, Seok-Cheon;Kim, Kwang-Suk
    • Transactions of the Korean Society of Automotive Engineers
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    • v.17 no.2
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    • pp.49-56
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    • 2009
  • In this study, a side collision accident reconstruction using database based on the deformed shape information from the collision test using model cars is suggested. A deformation index and angle index related to the deformed shape is developed to set the database for the collision accident reconstruction algorithm. Two small size RC cars are developed to carry out the side collision test. Several side collision tests according to the velocity and collision angles are performed for establishing the side collision database. A high speed camera with 1000fps is used to capture the motion of the car. A side collision accident reconstruction algorithm is developed and applied to find the collision conditions before the accident occurs. Two collision cases are tested to validate the database and the algorithm. The results obtained by the reconstruction algorithm show good match with original conditions with regard to the velocity and angle.

Investigation Into Protection Performance of Projectile Using Flying Plate (판재를 이용한 초고속 위협체의 방호성능에 대한 해석적 연구)

  • Choi, Hyoseong;Shin, Hyunho;Yoo, Yo-Han;Park, Jahng Hyon;Kim, Jong-Bong
    • Journal of the Korean Society for Precision Engineering
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    • v.33 no.12
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    • pp.1039-1045
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    • 2016
  • We investigated the protection capability of a plate against high speed projectiles demonstrating collision and penetration behaviors by finite element analysis. The element erosion method was used for penetration analysis, which showed that the speed of the projectile was slightly reduced by the collision with the protection plate. Protection capability was measured by the projectile's attitude angle change because the damage of our tanks by projectiles was also dependent on the projectile-tank collision angle. When the length of the protection plate was sufficiently long, the projectile was severely deformed and incapacitated. In the case of a small plate, the projectile was deformed only in the collision region. Thus, projection capability was investigated by the change of attitude angle. The effect of collision angle, velocity, and length of the plate on the rotational and vertical velocities of the projectile was investigated.

Testing, simulation and design of back-to-back built-up cold-formed steel unequal angle sections under axial compression

  • Ananthi, G. Beulah Gnana;Roy, Krishanu;Chen, Boshan;Lim, James B.P.
    • Steel and Composite Structures
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    • v.33 no.4
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    • pp.595-614
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    • 2019
  • In cold-formed steel (CFS) structures, such as trusses, transmission towers and portal frames, the use of back-to-back built-up CFS unequal angle sections are becoming increasingly popular. In such an arrangement, intermediate welds or screw fasteners are required at discrete points along the length, preventing the angle sections from buckling independently. Limited research is available in the literature on axial strength of back-to-back built-up CFS unequal angle sections. The issue is addressed herein. This paper presents an experimental investigation on both the welded and screw fastened back-to-back built-up CFS unequal angle sections under axial compression. The load-axial shortening and the load verses lateral displacement behaviour along with the deformed shapes at failure are reported. A nonlinear finite element (FE) model was then developed, which includes material non-linearity, geometric imperfections and modelling of intermediate fasteners. The FE model was validated against the experimental test results, which showed good agreement, both in terms of failure loads and deformed shapes at failure. The validated FE model was then used for the purpose of a parametric study to investigate the effect of different thicknesses, lengths and, yield stresses of steel on axial strength of back-to-back built-up CFS unequal angle sections. Five different thicknesses and seven different lengths (stub to slender columns) with two different yield stresses were investigated in the parametric study. Axial strengths obtained from the experimental tests and FE analyses were used to assess the performance of the current design guidelines as per the Direct Strength Method (DSM); obtained comparisons show that the current DSM is conservative by only 7% on average, while predicting the axial strengths of back-to-back built-up CFS unequal angle sections.

A Study on Plastic Strain Distribution of Machined Surface (기계가공면의 소성스트레인 분포에 관한 연구)

  • ;飯野 豊
    • Journal of The Korean Society of Manufacturing Technology Engineers
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    • v.9 no.6
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    • pp.111-117
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    • 2000
  • The plastically deformed layer in a machined surface must be considered in precision machining process. Therefore the analysis of the machined surface, including the plastic deformation and strain distribution should be carried out quantitatively. The subsequent recrystallization technique was presented for analysis of the plastically deformed layer in the machined surface, and the technique was successfully applied to determine the plastic strain in the machined surface. This investigation is to evaluate the plastic strain in the distance 0.1mm from the machined surface, and in particular, to find the effect of shear angle, shear strain, cutting energy etc. on the plastic strain.

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Deformation Behavior of 6063 Al Alloy Deformed by Shear-Drawing Method (전단-신선 가공된 6063 알루미늄 합금의 변형거동)

  • Ko, Young Gun;Lee, Byung Uk;Shin, Dong Hyuk
    • Korean Journal of Metals and Materials
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    • v.49 no.4
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    • pp.291-297
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    • 2011
  • This work investigated the microstructure and mechanical properties of 6063 Al alloy fabricated by shear-drawing (SD) technique where shear and drawing strains were combined together within a predetermined die. To find the optimum condition for sound deformation, three different dies having different inner angle and diameter of the exit channel were prepared. After single deformation of the present sample, the sound deformation took place without an abrupt failure of the sample if the inner angle would be greater than $135^{\circ}$ in this study, when the channel diameter of the SD die was reduced from 10 to 9 mm. Microstructural observation showed that the inner angle of $135^{\circ}$ was found to be more effective than that of $150^{\circ}$ in terms of the alignment of each grain to the shear direction imposed by SD method. In addition, the yield strength of the SD-deformed sample was twice higher than that of the initial counterpart while loosing ductility in tension.