• Title/Summary/Keyword: Inclination Angle

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Strain Gradient Crystal Plasticity Finite Element Modeling for the Compression Behaviors of Single Crystals (단결정 압축 변형 거동의 변형구배 결정소성 유한요소해석)

  • Jung, Jae-Ho;Cho, Kyung-Mox;Choi, Yoon Suk
    • Korean Journal of Materials Research
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    • v.27 no.12
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    • pp.679-687
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    • 2017
  • A strain-gradient crystal plasticity finite element method(SGCP-FEM) was utilized to simulate the compressive deformation behaviors of single-slip, (111)[$10{\bar{1}}$], oriented FCC single-crystal micro-pillars with two different slip-plane inclination angles, $36.3^{\circ}$ and $48.7^{\circ}$, and the simulation results were compared with those from conventional crystal plasticity finite element method(CP-FEM) simulations. For the low slip-plane inclination angle, a macroscopic diagonal shear band formed along the primary slip direction in both the CP- and SGCP-FEM simulations. However, this shear deformation was limited in the SGCP-FEM, mainly due to the increased slip resistance caused by local strain gradients, which also resulted in strain hardening in the simulated flow curves. The development of a secondly active slip system was altered in the SGCP-FEM, compared to the CP-FEM, for the low slip-plane inclination angle. The shear deformation controlled by the SGCP-FEM reduced the overall crystal rotation of the micro-pillar and limited the evolution of the primary slip system, even at 10 % compression.

Failure mechanism and bearing capacity of inclined skirted footings

  • Rajesh P. Shukla;Ravi S. Jakka
    • Geomechanics and Engineering
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    • v.35 no.1
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    • pp.41-54
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    • 2023
  • The use of a skirt, a vertical projection attached to the footing, is a recently developed method to increase the bearing capacity of soils and reduce foundation settlements. Most of the studies were focused on vertical skirted circular footings resting on clay while neglecting the rigidity and inclination of skirts. This study employs finite element limit analysis to investigate the bearing capacity enhancement of flexible and rigid inclined skirts in cohesionless soils. The results indicate that the bearing capacity initially improves with an increase in the skirt inclination but subsequently decreases for both flexible and rigid skirts. However, the rigid skirt exhibits more apparent optimum skirt inclination and bearing capacity enhancement than the flexible one, owing to differences in their failure mechanisms. Furthermore, the bearing capacity of the inclined skirted foundation increases with the skirt length, footing depth, and internal friction angle of the soil. In the case of rigid skirts, the bearing capacity increases linearly with skirt length, while for flexible skirts, it reaches a stable value at a certain skirt length. The efficiency of the flexible footing reduces as the footing depth and soil internal friction angle increase. Conversely, the efficiency of the rigid skirt decreases only with an increase in the depth of the footing. The paper also presents a detailed analysis of various failure patterns, highlighting the behaviour of inclined skirted footings. Additionally, nonlinear regression equations are provided to quantify and predict the bearing capacity enhancement with the inclined skirts.

DEM analysis of the anisotropy effects on the failure mechanism of the layered concretes' specimens with internal notches

  • Jinwei Fu;Vahab Sarfarazi;Hadi Haeri;Mohammad Fatehi Marji
    • Computers and Concrete
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    • v.33 no.6
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    • pp.659-670
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    • 2024
  • The mechanical behaviour of layered concrete samples containing an internal crack was numerically studied by modelling the geo-mechanical specimens in the particle flow code in two dimensions (PFC2D). The numerical modelling software was calibrated with the experimental results of the Brazilian tensile strengths gained from the laboratory disc-type specimens. Then, the samples with the bedding layers and internal notch were numerically simulated with PFC2D under uniaxial compressive loading. In each specimen, the layers' thickness was 10 mm but the layer's inclination angle was changed to 0°, 30°, 60°, 90°, 120° and 150°. Of course, the layers'interfaces are considered to have very low strengths. The internal notch was kept at 3 cm in length however, its inclination angle was changed to 0°, 40°, 60° and 90°. Therefore, a total, of 24 numerical models were made to study the failure mechanism of the layered concrete samples. Considering these results, it has been concluded that the inclination angles of both internal crack and bedding layers affect the failure mechanism and uniaxial compressive strength of the concrete.

Measurement of Normal Calcaneus in Korean Cadavers: A Preliminary Report (한국인 사체에서의 정상 종골의 실측: 예비보고)

  • Kim, Jung-Han;Gwak, Heui-Chul;Kim, Jeon-Gyo;Jung, Yang Hwan
    • Journal of Korean Foot and Ankle Society
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    • v.18 no.1
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    • pp.14-18
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    • 2014
  • Purpose: The purpose of this report is to evaluate the measured values of normal Korean calcaneus by conduct of a cadaveric study. Materials and Methods: A total of 42 calcanei were obtained from Korean cadavers. A digital goniometer was used for measurement of B$\ddot{o}$hler's angle, Gissane angle, posterior facet articular inclination angle, and Fowler-Philip angle of calcaneus. A vernier caliper was used for measurement of the maximal antero-posterior length, maximal transverse width, and maximal height of calcaneus. Results: The average B$\ddot{o}$hler's angle, Gissane angle, posterior facet articular inclination angle, and Fowler-Philip angle was $32.3^{\circ}{\pm}5.0^{\circ}$, $114.4^{\circ}{\pm}8.2^{\circ}$, $61.2^{\circ}{\pm}4.4^{\circ}$, and $60.3^{\circ}{\pm}7.6^{\circ}$. The average maximal antero-posterior length, maximal transverse width, and maximal height of calcaneus was $74.2{\pm}3.0mm$, $43.0{\pm}4.0mm$, and $42.5{\pm}3.0mm$. Conclusion: The measured values of normal Korean calcaneus were lower than the values reported in the international literature. Therefore, development of appropriate instruments reflecting the anatomical characteristics of Koreans will be needed.

A study on the Measurement of the Condyle Path Inclination in Relation to Skull Reference Lines by Roentgeno-Cephalometry (Roentgenocephalometry에 의한 한국인 과로와 두부참조선과의 각도계측에 관한 연구)

  • Yun, Young-Yun
    • The Journal of the Korean dental association
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    • v.11 no.2
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    • pp.134-138
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    • 1973
  • The author measured and analyzed the condyle path inclinations of 25 normal Korean adults roentgeno-cephalometrically and following conclusions were obtained. In protrusive movement of mandible, the angle of condyle pation inclination in relation to 1) occlusal plane is 19.86±8.25, 2) Frankfort Horizontal plane is 28.32±8.56, 3) Camper line is 12.22±4.06, 4) Nasion-sella line is 36.80±8.54.

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Effects of Balance Training through Various Ankle Inclination on Dynamic Balance in Healthy Adults (다양한 발목 경사를 통한 균형 훈련이 건강한 성인의 동적 균형에 미치는 영향)

  • Kim, Nuri;Kim, Kangmi;Lee, Jeongeun;Lee, Hakyeong;Cha, Yuri
    • Journal of Korean Physical Therapy Science
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    • v.25 no.3
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    • pp.61-67
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    • 2018
  • Background: The purpose of this study is to report the effect of balance training through various ankle inclination on dynamic balance in healthy adults. Methods: This study was participated in 20 healthy subjects. Twenty healthy adults were randomly divided into 10 ankle inclination group and 10 flat group, 3 kinds of exercised were performed in $30^{\circ}$ of the plantar flexion, $0^{\circ}$ of the neutral angle and $30^{\circ}$ of the dorsiflexion. Above 3 kinds of exercises were also performed in the flat group. Dynamic balance of each group was evaluated using a Figure-of-8 hop test, Up-down hop test, and Functional reach test before and after the experiment. Results: In the ankle inclination, the post-experiment showed a significant difference in Figure-of-8 hop test, Up-down hop test, and Functional reach test in comparison to pre-experiment(p<.05). Conclusion: The exercise applied in the ankle inclination is effective in improvement of the dynamic balance.

Unsteady aerodynamic force on a transverse inclined slender prism using forced vibration

  • Zengshun Chen;Jie Bai;Yemeng Xu;Sijia Li;Jianmin Hua;Cruz Y. Li;Xuanyi Xue
    • Wind and Structures
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    • v.37 no.5
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    • pp.331-346
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    • 2023
  • This work investigates the effects of transverse inclination on an aeroelastic prism through forced-vibration wind tunnel experiments. The aerodynamic characteristics are tri-parametrically evaluated under different wind speeds, inclination angles, and oscillation amplitudes. Results show that transverse inclination fundamentally changes the wake phenomenology by impinging the fix-end horseshoe vortex and breaking the separation symmetry. The aftermath is a bi-polar, one-and-for-all change in the aerodynamics near the prism base. The suppression of the horseshoe vortex unleashes the Kármán vortex, which significantly increases the unsteady crosswind force. After the initial morphology switch, the aerodynamics become independent of inclination angle and oscillation amplitude and depend solely on wind speed. The structure's upper portion does not feel the effect, so this phenomenon is called Base Intensification. The phenomenon only projects notable impacts on the low-speed and VIV regime and is indifferent in the high-speed. In practice, Base Intensification will disrupt the pedestrian-level wind environment from the unleashed Bérnard-Kármán vortex shedding. Moreover, it increases the aerodynamic load at a structure base by as much as 4.3 times. Since fix-end stiffness prevents elastic dissipation, the load translates to massive stress, making detection trickier and failures, if they are to occur, extreme, and without any warnings.

Geometric morphometric analysis of mandibular symphysis in Class III skeletal base

  • Kui Fei Teo;Murshida Marizan Nor;Alizae Marny Mohamed;Helmi Mohd Hadi Pritam
    • Anatomy and Cell Biology
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    • v.55 no.4
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    • pp.433-440
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    • 2022
  • This study aimed to investigate the general mandibular symphysis (MS) shape variation among Class III skeletal base, using geometric morphometric analysis. Pre-treatment lateral cephalometric radiographs of 254 patients aged 11-40 years old, with Class III skeletal base (ANB <1°) and lower incisor angle (<99°) were included. Nine-landmarks with x and y coordinates were identified on MS using TPSDig2 software, then exported into Morpho J for shape and statistical analysis. Principal component analysis showed that three main shape dimensions with a total variance of 74.6% represented the majority variation of samples. Procrustes Anova showed the shape of MS in Class III skeletal base to be mainly influenced by gonial angle, incisor inclination and sex (P<0.0001). Canonical variate analysis showed that high gonial angle groups had significantly narrower and elongated MS whereas low gonial angle groups had wider, bulbous and rounded MS (P<0.0001). The ratio of alveolar part to basal part was 1:5 in low gonial angle and 2:3 in high gonial angle. Males had significantly taller MS with narrower B point area compared to females (P<0.0001). Retroclined incisors exhibited taller and retroclined alveolar parts (P<0.0001). The shape of MS in Class III skeletal base varied at the alveolar part, basal part or both and it is influenced by gonial angle, incisor inclination and sex. Hence, understanding the shape variation of MS is important to aid orthodontic treatment planning.

Relationships between the upper central incisor crown forms and degree of labial inclination, overbite, and overjet in Japanese young adults

  • Kurita, Takeshi;Mizuhashi, Fumi;Sato, Toshihide;Koide, Kaoru
    • The Journal of Advanced Prosthodontics
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    • v.12 no.6
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    • pp.338-343
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    • 2020
  • PURPOSE. The present study aimed to investigate the relationships between the crown form of the upper central incisor and their labial inclination, overbite, and overjet. MATERIALS AND METHODS. Maxillary and mandibular casts of 169 healthy dentitions were subjected to 3D dental scanning, and analyzed using CAD software. The crown forms were divided into tapered, square, and ovoid based on the mesiodistal dimensions at 20% of the crown height to that at 40%. The degree of labial inclination of the upper central incisor was defined as the angle between the occlusal plane and the line connecting the incisal edge and tooth cervix. The incisal edges of the right upper and lower central incisor that in contact with lines parallel to the occlusal plane were used to determine the overbite and overjet. One-way ANOVA was performed to compare the labial inclination, overbite, and overjet among the crown forms. RESULTS. The crown forms were classified into three types; crown forms with a 20%/40% dimension ratio of 1.00±0.01 were defined as square, >1.01 as tapered, and <0.99 as ovoid. The labial inclination degree was the greatest in tapered and the least in square. Both overbite and overjet in tapered and ovoid were higher than those in square. CONCLUSION. Upper central incisor crown forms were related to their labial inclination, overbite, and overjet. It was suggested that the labial inclination, overbite, and overjet should be taken into consideration for the prosthetic treatment or restoring the front teeth crowns.

Three Dimensional Finite Element Inverse Analysis of Rectangular Cup and S-Rail Forming Processes using a Direct Mesh Mapping Method (직접 격자 사상법을 이용한 직사각컵 및 S-Rail 성형공정의 3차원 유한요소 역해석)

  • Kim S. H.;Huh H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.10a
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    • pp.81-84
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    • 2001
  • An inverse finite element approach is employed for more capability to design the optimum blank shape from the desired final shape with small amount of computation time and effort. In some drawing or stamping simulation with inverse method, it is difficult to apply inverse scheme due to the large aspect ratio or steep vertical angle of inclination. The reason is that initial guesses are hard to make out with present method for those cases. In this paper, a direct mesh marring scheme to generate initial guess on the sliding constraint surface described by finite element patches is suggested for one step inverse analysis to calculate initial blank shape. Radial type mapping is adopted for the simulation of rectangular cup drawing process with large aspect ratio and parallel type mapping for the simulation of S-Rail forming process with steep vertical angle of inclination.

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