• Title/Summary/Keyword: Transverse

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Retrofitting reinforced concrete beams by bolting steel plates to their sides -Part 2: Transverse interaction and rigid plastic design

  • Oehlers, Deric John;Ahmed, Marfique;Nguyen, Ninh T.;Bradford, Mark Andrew
    • Structural Engineering and Mechanics
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    • v.10 no.3
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    • pp.227-243
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    • 2000
  • In a companion paper, tests on bolted side plated beams have shown that side plates can substantially increase the strength of existing reinforced concrete beams with little if any loss of ductility and, furthermore, induce a gradual mode of failure after commencement of concrete crushing. However, it was also shown that transverse interaction between the side plates and the reinforced concrete beam, that is vertical slip and which is a concept unique to side plated beams, is detrimental. Transverse interaction increases the forces on the bolt shear connectors and, hence, weakens the beam. It also reduces the ability of the composite plated beam to yield and, hence, to attain its full flexural capacity. The generic concept of transverse interaction will be described in this paper and the results used to develop a new form of rigid plastic analysis for bolted side plated beams which is illustrated with an application.

A Case Report of a Patient with Relapsing Transverse Myelitis Treated by Korean Medical Treatment (재발성 횡단성 척수염 환자의 한방치험 1례)

  • Lee, Ook Jae;Lee, Dong Geun;Lee, Ju Hee;Lee, Jung Hun;Kim, Seon Wook;Shin, Jeong Cheol
    • Journal of Acupuncture Research
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    • v.31 no.4
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    • pp.155-162
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    • 2014
  • Objectives : The purpose of this study is to report the effect of Korean medical treatment on a patient with relapsing transverse myelitis. Methods : The patient was treated using acupuncture, pharmacopuncture, herbal medicine and other treatments including moxibustion and therapeutic exercise for 8 weeks. We evaluated the patient's motor grade with medical research council(MRC) scale and evaluated active range of motion in the hip, knee, and anke joint. Results : Through treatment the patient's motor grade and active range of motion all improved. Other symptoms such as lower limb hypoesthesia and residual urine sensation also showed improvement. Conclusions : We concluded that Korean medicine treatment had respectable effect in improving symptoms on the patient with relapsing transverse myelitis.

A Study on the Free Vibration Responses of Various Buried Pipelines (각종 매설관의 자유진동거동에 관한 연구)

  • Jeong, Jin-Ho;Park, Byung-Ho;Kim, Sung-Ban;Kim, Chun-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1340-1347
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    • 2006
  • Dynamic response of buried pipelines both in the axial and the transverse directions on concrete pipe and steel pipe, FRP pipe were investigated through a free vibration analysis. End boundary conditions considered herein consist of free ends, fixed ends, and fixed-free ends in the axial and the transverse direction. Guided ends, simply supported ends, and supported-guided ends were added to the transverse direction. The buried pipeline was regarded as a beam on an elastic foundation and the ground displacement of sinusoidal wave was applied to it. Natural frequencies and mode shapes were determined according to end boundary conditions. In addition, the effects of parameters on the natural frequency were evaluated. The natural frequency is affected most significantly by the soil stiffness and the length of the buried pipelines. The natural frequency increases as the soil stiffness increases while it decreases as the length of the buried pipeline increases. Such behavior appears to be dominant in the axial direction rather than in the transverse direction of the buried pipelines.

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Load transfer and energy absorption in transversely compressed multi-walled carbon nanotubes

  • Chen, Xiaoming;Ke, Changhong
    • Coupled systems mechanics
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    • v.6 no.3
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    • pp.273-286
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    • 2017
  • We present a simple and easy-to-implement lumped stiffness model to elucidate the load transfer mechanism among all individual tube shells and intertube van der Waals (vdW) interactions in transversely compressed multi-walled carbon nanotubes (CNTs). Our model essentially enables theoretical predictions to be made of the relevant transverse mechanical behaviors of multi-walled tubes based on the transverse stiffness properties of single-walled tubes. We demonstrate the validity and accuracy of our model and theoretical predictions through a quantitative study of the transverse deformability of double- and triple-walled CNTs by utilizing our recently reported nanomechanical measurement data. Using the lumped stiffness model, we further evaluate the contribution of each individual tube shell and intertube vdW interaction to the strain energy absorption in the whole tube. Our results show that the innermost tube shell absorbs more strain energy than any other individual tube shells and intertube vdW interactions. Nanotubes of smaller number of walls and outer diameters are found to possess higher strain energy absorption capacities on both a per-volume and a per-weight basis. The proposed model and findings on the load transfer and the energy absorption in multi-walled CNTs directly contribute to a better understanding of their structural and mechanical properties and applications, and are also useful to study the transverse mechanical properties of other one-dimensional tubular nanostructures (e.g., boron nitride nanotubes).

Chest Wall Reconstruction with a Transverse Rectus Abdominis Musculocutaneous Flap in an Extremely Oversized Heart Transplantation

  • Yim, Ji Hong;Eom, Jin Sup;Kim, Deok Yeol
    • Archives of Reconstructive Microsurgery
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    • v.23 no.2
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    • pp.89-92
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    • 2014
  • An 8-year-old girl diagnosed with dilated cardiomyopathy and Russell-Silver syndrome was admitted to our pediatric intensive care unit due to low cardiac output and multiple-organ dysfunction. The patient was placed on the heart transplant waiting list and extracorporeal membrane oxygenation was performed as a bridge to transplantation. After 17 days, heart transplantation was performed. The donor was a 46-year-old female (weight, 50 kg; height, 150 cm). The donor:recipient weight ratio was 3.37:1. Because the dimension and volume of the recipient's thoracic cage were insufficient, the sternum could not be closed. Nine days after transplantation, the patient underwent delayed sternal closure. To obtain adequate space, we left the sternum 4.5 cm apart from each margin using four transverse titanium plates. A transverse rectus abdominis musculocutaneous flap was chosen to cover the wound. Due to the shortage of donors, a size-mismatched pediatric heart transplantation is sometimes unavoidable. Closure of the opened sternum of a transplant recipient can be challenging. Sternal reconstruction after an extremely oversized heart transplantation with transverse titanium plate fixation and a musculocutaneous flap can effectively achieve sternal closure and stability.

Evaluation of Structural Performance of RC T-shaped Walls with Different ratios of axial load and vertical reinforcement (압축력비와 수직철근비에 따른 RC T형 벽체의 구조성능 평가에 관한 해석적 연구)

  • 하상수;최창식;이리형
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.403-408
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    • 2003
  • The objective of this study is to understand the variables affected the confinement for the transverse reinforcement of the reinforced concrete structural walls with the T-shaped cross section subjected to cyclic lateral loads. The structural performance of T-shaped walls was advanced by the transverse reinforcement which restrained the concrete subjected to compressive stress. If the arrangement of transverse reinforcement was not suitable for the confinement, T-shaped walls happened the brittle failure by web crushing or bucking of vertical reinforcement at the compression zone. It is necessary to confine transverse reinforcement in order to prevent the these failure. But the location of neutral axis and the magnitude of ultimate strain vary according to the section shape, a ratio of axial load, a ratio of wall cross sectional area to the floor-plan area, an aspect ratio and the reinforcement ratio. Therefore, the objective of this research is to grasp the location of neutral axis and the range which needs for the confinement of transverse reinforcement through the results of the sectional analysis which varies the ratio of axial load and the ratio of vertical reinforcement.

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Damage Detection and Suppression in Composites Using Smart Technologies

  • Takeda, Nobuo
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.26-36
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    • 2001
  • Smart sensors and actuators have recently been developed. In this study, first, small-diameter fiber Bragg grating (FBG) sensors developed by the author, whose cladding and polyimide coating diameters were 40 and $52{\mu}m$, respectively, were embedded inside a laminate without resin-rich regions around sensors and the deterioration of mechanical properties of the composite laminate. The small-diameter FBG sensor was embedded in $0^{\circ}$ ply of a CFRP laminate for the detection of transverse cracks in $90^{\circ}$ ply of the laminate. The reflection spectra from the FBG sensor were measured at various tensile stresses. The spectrum became broad and had some peaks with an increase of the transverse crack density. Furthermore, the theoretical calculation reproduced the change in the spectrum very well. These results show that the small-diameter FBG sensors have a potential to detect the occurrence of transverse cracks through the change in the form of the spectrum, and to evaluate the transverse crack density quantitatively by the spectrum width. On the other hand, shape memory alloy (SMA) films were used to suppress the initiation and growth of transverse cracks in CFRP laminates. Pre-strained SMA films were embedded between laminas in CFRP laminates and then heated to introduce the recovery stress in SMA films and compressive stresses in the weakest plies ($90^{\circ}$ ply). The effects of recovery stresses are demonstrated in the experiments and well predicted using the shear-lag analysis and the nonlinear constitutive equation of SMA films.

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Experience of Epidural Steroids in Transverse Myelitis -A case report- (횡단척수염 환자에서 경막외 스테로이드 투여에 의한 치료 경험 -증례보고-)

  • Nam, Voki;Mun, Ho Sik;Kim, Jung Hak;Kim, Dae Sung;Sung, Choon Ho
    • The Korean Journal of Pain
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    • v.22 no.1
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    • pp.92-95
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    • 2009
  • Transverse myelitis is a focal inflammatory disorder of the spinal cord characterized by motor, sensory, and autonomic dysfunction. A 41-year-old man with transverse myelitis and no pre-existing neurologic disease presented with hypesthesia, numbness, weakness in the both lower extremities, back pain, decreased libido, constipation, and dysuria. A MRI test showed intramedullary high signal intensity between T4 and T8 on a T2-weighted image. After high-dose intravenous methylprednisolone and oral prednisolone therapy, he showed facial swelling and acneiform eruption. Therefore, we injected 40 mg methylprednisolone via an epidural route. A 7-dose serial treatment improved most symptoms. A follow up MRI showed radiological improvement. We report a case of transverse myelitis treated by epidural steroids.

A Study on the Dynamic Characteristics of a Composite Beam with a Transverse Open Crack (크랙이 존재하는 복합재료 보의 동적 특성 연구)

  • 하태완;송오섭
    • Journal of KSNVE
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    • v.9 no.5
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    • pp.1019-1028
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    • 1999
  • Free vibration characteristics of cantilevered laminated composite beams with a transverse non0propagating open carck are investigated. In the present analysis a special ply-angle distribution referred to as asymmetric stiffness configuration inducing the elastic coupling between chord-wise bending and extension is considered. The open crack is modelled as an equivalent rotational spring whose spring constant is calculated on the basis of fracture mechanics of composite material structures. Governing equations of a composite beam with a open crack are derived via Hamilton's Principle and Timoshenko beam theory encompassing transverse shear and rotary inertia effect. the effects of various parameters such as the ply angle, fiber volume fraction, crack depth, crack position and transverse shear on the free vibration characteristics of the beam with a crack is highlighted. The numerical results show that the natural frequencies obtained from Timoshenko beam theory are always lower than those from Euler beam theory. The presence of intrinsic cracks in anisotropic composite beams modifies the flexibility and in turn free vibration characteristics of the structures. It is revealed that non-destructive crack detection is possible by analyzing the free vibration responses of a cracked beam.

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A Study on the Behavior of a Spinning Flexible Disk near a Curved Wall (곡률이 있는 벽면근처에서 고속회전하는 유연디스크의 거동 해석)

  • Lee, Ho-Ryul;Rhim, Yoon-Chul
    • Transactions of the Society of Information Storage Systems
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    • v.2 no.3
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    • pp.201-207
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    • 2006
  • Information storage devices have been studied to increase the storage capacity and the data transfer rate as well as to decrease the access time and their physical sizes. Optical information storage devices have been achieved high-capacity by reducing optical spot size remarkably due to the development of Blue-ray technology. Optical information storage devices usually use 1.2mm-thick polycarbonate(PC) media to get high enough stiffness. However, it would be better if we can decrease the thickness of a disk for achieving thinner device while keeping the capacity as large as possible. Decreasing the thickness of the storage media makes it difficult to read and write data because it increases the transverse vibration of the rotating disk due to the interaction with surrounding air and the vibration characteristics of thin flexible disk itself, Therefore, a special design based on the fluid mechanics is required to suppress the transverse vibration of the disk in non-contact manner so that the optical pickup can read/write data successfully. In this study, a curved wall is proposed as a stabilizer to suppress the transverse vibration of a $95{\mu}m$-thick PC disk. The characteristics of disk vibration due to a curved wall have been studied through numerical and experimental analysis from the fluid mechanics point of view. The proposed shapes are possible candidates as stabilizers to suppress the transverse vibration of a flexible disk which rotates at high speed.

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