• Title/Summary/Keyword: out-of plane

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Plastic loads of pipe bends under combined pressure and out-of-plane bending (면외 굽힘하중과 내압의 복합하중을 받는 곡관의 소성하중)

  • Lee, Kuk-Hee;Kim, Yun-Jae;Park, Chi-Yong;Lee, Sung-Ho;Kim, Tae-Ryong
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1836-1841
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    • 2007
  • Based on three-dimensional (3-D) FE limit analyses, this paper provides plastic limit and TES(Twice-Elastic-Slope) loads for pipe bends under combined pressure and out-of-plane bending. The plastic limit loads are determined from FE limit analyses based on elastic-perfectly-plastic materials using the small geometry change option, and the FE limit analyses using the large geometry change option provide TES plastic loads. A wide range of parameters related to the bend geometry is considered. Based on the FE results, closed-form approximations of plastic limit and TES plastic load solutions for pipe bends under out-of-plane bending are proposed.

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Effect of Initial Defects on Welding Deformation and Residual Stress (강판의 초기不整이 용접변형.잔류응력에 미치는 영향)

  • 박정응
    • Journal of Welding and Joining
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    • v.17 no.4
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    • pp.76-84
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    • 1999
  • The residual stress generated when the steel plates were produced, did not influence on the out-of-plane deformation and residual stress generated by welding. When the initial deflection shape was a concave(Type I), the out-of-plane deformation became the same shape as that of the initial deflection and its magnitude became small. When the initial deflection made a winding in the welding direction(Type III), the out-of-plane deformation became large in the plate width. The initial deflection shape did not influence on residual stress and plastic strain produced by welding.

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Development of Ply-Lam Composed of Japanese Cypress Laminae and Korean Larch Plywood

  • FUJIMOTO, Yoshiyasu;TANAKA, Hiroshi;MORITA, Hideki;KANG, Seog Goo
    • Journal of the Korean Wood Science and Technology
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    • v.49 no.1
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    • pp.57-66
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    • 2021
  • In recent years, the use of cross laminated timber (CLT) has been evolving. In addition, CLT manufactured with various species such as Japanese cedar has been developed to utilize the local resources in each country. However most factories in Japan produce CLT by bonding the laminae in width direction for orthogonal layers, where grain of element is perpendicular to the grain of outer layer, and this process is considered to be one of the factors that reduce productivity. A new wood based material (hereinafter referred to as Ply-lam) using wooden panel such as plywood for the orthogonal layer was developed in order to improve productivity in CLT manufacturing and improve quality. Japanese cypress lamina was used for the parallel layer, where grain of element is parallel to the grain of outer layer, of CLT and Korean larch plywood was used for the orthogonal layer, in order to effectively use Korean larch and expand the utilization of Japanese cypress. The cross-sectional construction of the Ply-lam was 5-layers 5-plies, and the dimensions were 1000 mm (width) × 150 mm (depth) × 4000 mm (length). As a performance evaluation of the manufactured Ply-lam, strength tests such as out-of-plane bending, in-plane bending, out-of-plane shearing and in-plane shearing tests were carried out. As the result of this study, Ply-lam composed of Japanese cypress lamina panels and Korean larch plywood showed very higher out-of-plane bending strength compared to the standard strength of CLT. And the result obtained in other tests seems to show a sufficiently high value.

Fatigue analysis on the mooring chain of a spread moored FPSO considering the OPB and IPB

  • Kim, Yooil;Kim, Min-Suk;Park, Myong-Jin
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.11 no.1
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    • pp.178-201
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    • 2019
  • The appropriate design of a mooring system to maintain the position of an offshore structure in deep sea under various environmental loads is important. Fatigue design of the mooring line considering OPB/IPB(out-of-plane bending/in-plane bending) became an essential factor after the incident of premature fatigue failure of the mooring chain due to OPB/IPB in the Girassol region in West Africa. In this study, mooring line fatigue analysis was performed considering the OPB/IPB of a spread moored FPSO in deep sea. The tension of the mooring line was derived by hydrodynamic analysis using the de-coupled analysis method. The floater motion time histories were calculated under the assumption that the mooring line behaves in quasi-static manner. Additional time domain analysis was carried out by prescribing the obtained motions on top of the selected critical mooring line, which was determined based on spectral fatigue analysis. In addition, nonlinear finite element analysis was performed considering the material nonlinearities, and both the interlink stiffness and stress concentration factors were derived. The fatigue damage to the chain surface was estimated by combining both the hydrodynamic and stress analysis results.

Measurement of Out-of-plane Displacement in a Spot Welded Canti-levered Plate using Laser Speckle Interferometry with 4-step Phase Shifting Technique (레이저스펙클 간섭법과 4단계 위상이동법에 의한 외팔보 점용접부의 면외 변위측정)

  • Baek, Tae-Hyun;Kim, Myung-Soo;Na, Eui-Gyun;Koh, Seung-Ki
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.3
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    • pp.66-72
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    • 2002
  • Electronic Speckle Pattern Interferometry (ESPI) has been recently developed and widely used because it has advantage to be able to measure surface deformations of engineering components and materials in industrial areas with non-contact. The speckle patterns to be formed with interference and scattering phenomena can measure not only out-of-plane but also in-plane deformations, together with the use of digital image equipment to process the informations included in the speckle patterns and to display consequent interferogram on a computer monitor. In this study, the experimental results of a canti-levered plate using ESPI were compared with those obtained from the simple beam theory. The ESPI results of the canti-levered plate analyzed by 4-step phase shifting method are close to the theoretical expectation. Also, out-of-plane displacements of a spot welded cacti-levered plate were measured by ESPI with 4-step phase shifting technique. The phase map of the spot welded cacti-levered plate is quite different from that of the canti-levered plate without spot welding.

Dynamic Interfacial Crack in Bonded Anisotropic Strip Under Out-of-Plane Deformation (면외변형하의 이방성 띠판에 대한 동적계면균열)

  • Park, Jae-Wan;Choe, Seong-Ryeol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.6
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    • pp.949-958
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    • 2001
  • A semi-infinite interfacial crack propagated with constant velocity in two bonded anisotropic strips under out-of-plane clamped displacements is analyzed. Using Fourier integral transform the problem is formulated and the Wiener-Hopf equation is derived. By solving this equation the asymptotic stress and displacement fields near the crack tip are obtained, where the results get more general expressions applicable not only to isotropic/orthotropic materials but also to the extent of the anisotropic material having one plane of elastic symmetry for the interfacial crack. The dynamic stress intensity factor is obtained as a closed form, which is decreased as the velocity of crack propagation increases. The critical velocity where the stress intensity factor comes to zero is obtained, which agrees with the lower value between the critical values of parallel crack merged in the material 1 and 2 adjacent to the interface. Using the near tip fields of stresses and displacements, the dynamic energy release rate is also obtained as a form of the stress intensiy factor.

Theoretical investigation on rain-wind induced vibration of a continuous stay cable with given rivulet motion

  • Li, Shouying;Chen, Zhengqing;Li, Shouke
    • Wind and Structures
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    • v.19 no.5
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    • pp.481-503
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    • 2014
  • A new theoretical model on rain-wind induced vibration (RWIV) of a continuous stay cable is developed in this paper. Different from the existing theoretical analyses in which the cable was modeled as a segmental rigid element, the proposed scheme focuses on the in-plane and out-of-plane responses of a continuous stay cable, which is identical with the prototype cable on cable-stayed bridge. In order to simplify the complexities, the motion law of the rivulet on the cable surface is assumed as a sinusoidal way according to some results obtained from wind tunnel tests. Quasi-steady theory is utilized to determine the aerodynamic forces on the cable. Equations of motion of the cable are derived in a Cartesian Coordinate System and solved by using finite difference method to obtain the in-plane and out-of-plane responses of the cable. The results show that limited cable amplitudes are achieved within a limited range of wind velocity, which is a unique characteristic of RWIV of stay cable. It appears that the in-plane cable amplitude is much larger than the out-of-plane cable amplitude. Rivulet frequency, rivulet distribution along cable axis, and mean wind velocity profile, all have significant effects on the RWIV responses of the prototype stay cable. The effects of damping ratio on RWIVs of stay cables are carefully investigated, which suggests that damping ratio of 1% is needed to well mitigate RWIVs of prototype stay cables.

Simultaneous Periareolar Augmentation Mastopexy: Dual Plane Versus Subfascial Plane (동시 유륜절개 유방하수교정술 및 확대술: 이중평면 대 근막밑평면)

  • Sim, Hyung Bo;Yoon, Sang Yub
    • Archives of Plastic Surgery
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    • v.34 no.1
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    • pp.105-110
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    • 2007
  • Purpose: The major drawback of submuscular augmentation of the ptotic breast is a "double-bubble" deformity. If a traditional mastopexy is added to correct the ptosis, there would be additional scars. This article describes simultaneous periareolar mastopexy with dual plane or subfascial breast augmentations. Methods: A series of 81 patients with grade I or II ptosis underwent the procedure from 1999 to 2005. Out of these, dual plane augmentation was done in 71 cases and subfascial plane in 10. After periareolar skin excision, an incision is made perpendicularly down to the fascia of pectoralis. At the lower pole, all breast implants are inserted into the subfascial plane. In case of upper pole thickness of above 20 mm, we inserted the implant into the subfascial plane, whereas below 20 mm, we inserted that into the submuscular plane. Results: No major complications were noted and patients' satisfactory score was high. This technique avoids the "double-bubble" deformity and leaves a minimal periareolar scar. Conclusion: Simultaneous periareolar mastopexy/breast augmentation is useful for correction of the ptotic breast, increasing the volume of breast and providing the natural breast shape with minimal scars. We consider that subfascial plane augmentation with periareolar mastopexy to be an alternative for cases with breast upper pole thickness of at least above 20 mm.

A Study on Out-of-Plane Flexural Behavior of the Structure with a Vertical Plane Connection between a Reinforced Concrete Wall and a Steel Plate Concrete Wall (철근 콘크리트 벽과 강판 콘크리트 벽이 수직으로 만나는 이질접합 구조물의 면외 휨 거동 특성 연구)

  • Hwang, Kyeong Min;Lee, Kyung Jin;Hahm, Kyung Won;Kim, Won Ki
    • Journal of Korean Society of Steel Construction
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    • v.25 no.1
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    • pp.93-102
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    • 2013
  • This paper describes the experimental study on the structural behavior of the vertical plane connection between a reinforced concrete wall and a steel plate concrete wall under out-of-plane flexural loads. The specimen was tested under a dynamic test with the use of cyclic loads. As a result of the test, ductile failure mode of vertical bars was shown under a push load and the failure load was more than that of the nominal strength of the specimen. However, the shear failure mode of the connection was confirmed in case of a pull test and thus demonstrates a need for a shear reinforcement.