• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.132-142
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• 1999

In this paper, a new formula for primary and secondary thrust of metal belt CVT is proposed considering variation of band tension, block compression and active arc for each of the primary and secondary pulleys. For the secondary thrust, effective friction coefficient is introduced considering the effect of flange deflection. Nondimensional primary and secondary thrust of the metal belt CVT by the new formula agree well with the experimental results except for low torque range, $0\;<\;{\lambda}\;<\;0.2$ at speed ration i = 1.0. The new formula can be used in design of the primary and secondary thrusts control system for the metal belt CVT.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.2
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• pp.1-7
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• 2018

Suspension bridge cables made of high strength steel wires require periodical maintenance in accordance with the axial force of cable-band bolts, since the bolts in suspension bridges can undergo tension decrease due to creep of cable wires, bolt relaxation, load fluctuation, and cable re-arrangement, etc. Consequently, this study is aimed at investigating and subsequently evaluating the critical factors with respect to the bolt tension-decrease phenomenon in SR suspension bridge in Korea, based on field monitoring, theoretical studies, and field record management works. From the observation, it is interesting to note that the decrease in the bolt tension force is typically accompanied by plastic deformation of the zinc plating layers in the cable wires. In addition, a framework corresponding to generic methodologies to characterize the deformation in terms of the bolt tension-decrease and long-term history management has been developed in this exploratory study.

• Clinics in Shoulder and Elbow
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• v.16 no.1
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• pp.33-39
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• 2013

Purpose: The aim of this study is to evaluate the clinical result of intra-articular fractures of the distal humerus (AO type C) in elderly osteoporotic patients treated with double tension band osteosynthesis. Materials and Methods: From January 2006 to December 2010, 10 elderly osteoporotic patients(1 male, 9 females) with intra-articular fractures of the distal humerus (AO type C) were treated with double tension band osteosynthesis. The mean age of patients at the time of surgery was 74.6(66~84) years and the mean follow-up period was 39.2(20~74) months. The fracture union and complications were assessed and the functional result was evaluated by the rating system of Jupiter et al. and the Mayo elbow performance index. Results: Bone union was achieved in all patients with no secondary displacement. The mean time for union was 16.6(13~22) weeks. The average postoperative arc of elbow flexion was 119(100~140) degrees with a mean flexion contracture of 8.5(0~15) degrees. The recovery in two patients was rated as excellent, in 7 as good, and in 1 as fair in terms of the Mayo elbow performance index with average value of 82(70~90) points. Seven patients were rated as excellent, 1 as good, and 2 as fair in terms of the rating system of Jupiter et al. Changing tension band wiring was performed in one patient as skin irritation was noticed due to tension band knots. Heterotopic ossification developed in one patient but had no symptom. Conclusion: Double tension band osteosynthesis in intra-articular fractures of distal humerus (AO type C) in elderly osteoporotic patients can provide sufficient and secure stability to allow early rehabilitation.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 1995.05a
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• pp.17-17
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• 1995

• The Academic Congress of Korean Shoulder and Elbow Society
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• 1999.03a
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• pp.73-73
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• 1999

• Asian Spine Journal
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• v.12 no.6
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• pp.967-972
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• 2018

Study Design: Biomechanical study. Purpose: To investigate the relative stiffness of a new posterior pelvic fixation for unstable vertical fractures of the sacrum. Overview of Literature: The reported operative fixation techniques for vertical sacral fractures include iliosacral screw, sacral bar fixations, transiliac plating, and local plate osteosynthesis. Clinical as well as biomechanical studies have demonstrated that these conventional techniques are insufficient to stabilize the vertically unstable sacral fractures. Methods: To simulate a vertically unstable fractured sacrum, 12 synthetic pelvic models were prepared. In each model, a 5-mm gap was created through the left transforaminal zone (Denis zone II). The pubic symphysis was completely separated and then stabilized using a 3.5-mm reconstruction plate. Four each of the unstable pelvic models were then fixed with two iliosacral screws, a tension band plate, or a transiliac fixation plus one iliosacral screw. The left hemipelvis of these specimens was docked to a rigid base plate and loaded on an S1 endplate by using the Zwick Roell z010 material testing machine. Then, the vertical displacement and coronal tilt of the right hemipelves and the applied force were measured. Results: The transiliac fixation plus one iliosacral screw constructions could withstand a force at 5 mm of vertical displacement greater than the two iliosacral screw constructions (p=0.012) and the tension band plate constructions (p=0.003). The tension band plate constructions could withstand a force at $5^{\circ}$ of coronal tilt less than the two iliosacral screw constructions (p=0.027) and the transiliac fixation plus one iliosacral screw constructions (p=0.049). Conclusions: This study proposes the use of transiliac fixation in addition to an iliosacral screw to stabilize vertically unstable sacral fractures. Our biomechanical data demonstrated the superiority of adding transiliac fixation to withstand vertical displacement forces.

• Korean Journal of Veterinary Research
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• v.63 no.3
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• pp.24.1-24.6
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• 2023

This study compared the biomechanical properties of bone-stapling techniques with those of other fixation methods used for stabilizing tibial tuberosity fractures using 3-dimensionally (3D)-printed canine bone models. Twenty-eight 3D-printed bone models made from computed tomography scan files were used. Tibial tuberosity fractures were simulated using osteotomy. All samples were divided into 4 groups. Group 1 was stabilized with a pin and tension-band wire; group 2, with a pin and an 8 mm-wide bone staple; group 3, with 2 horizontally aligned pins and an 8 mm-wide bone staple; and group 4 with a 10 mm-wide bone staple. Tensile force was applied with vertical distraction until failure occurred. The load and displacement were recorded during the tests. The groups were compared based on the load required to cause displacements of 1, 2, and 3 mm. The maximum failure loads and modes were recorded. The loads at all displacements in group 4 were greater than those in groups 1, 2, and 3. The loads at 1, 2, and 3 mm displacements were similar in groups 1 and 3. There was no significant difference between groups 1 and 3. Groups 1 and 4 provided greater maximum failure loads than groups 2 and 3. Failure occurred because of tearing of the nylon rope, tibial fracture, wire breakage, pin bending, and fracture around the bone staple insertion. In conclusion, these results demonstrate that the bone-stapling technique is an acceptable alternative to tension-band wire fixation for the stabilization of tibial tuberosity fractures in canine bone models.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.18 no.2
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• pp.207-213
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• 2009

The bundling process is the final step in vegetable manufacturing, however, the process is a little difficult to be automatized, because vegetable has the physical properties of roughness, softness, and fragility etc. In this paper, we proposed an automatic bundling mechanism for vegetable based on the heat melt sticking. The proposed mechanism consists of three modules, one module is the moving part for aligning of the vegetable shape and adjusting of the vegetable tension, second module is the arm driving part for the vegetable binding and the band roll releasing, and third module is band joining, band cutting, and band feeding part for the vegetable binding continuously. Through this research, Using the SMO(SimDesigner Motion) module, we optimize condition of mechanical movement of the bundling mechanism. This bundling system designed in order to binding 288 bundle/hour.

• Electrical & Electronic Materials
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• v.10 no.8
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• pp.770-777
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• 1997

Some polymer materials including epoxy resin are being instead of porcelain for outdoor insulating materials such as insulators bushings cable terminators and surge arrester housing. And the largest problem to be overcomed is the tracking and erosion of the outdoor polymer material brought about by dry band arcing during prolonged exposure to contaminations. In this paper the effect of surface tension wettability flow rate of contaminants with varying surfactant content and frequency of applied voltage on the tracking breakdown of epoxy insulating materials were investigated. As the flow rate of contaminant is increased the surface resistivity is decreased and the leakage current is increased the time to tracking breakdown is decreased. It is found that time to tracking breakdown depends on the surface tension of contaminant that is difference of wettability. And as the frequency of applied voltage is increased time to tracking breakdown decreased.

• Composites Research
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• v.32 no.5
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• pp.258-264
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• 2019

In this paper, a progressive failure analysis method was developed using the Hashin failure criterion and crack band model. Using the failure criterion, the failure initiation was evaluated. If the failure initiation is occurred, the damage variables at each failure modes (fiber tension & compression, matrix tension & compression) was calculated according to linear softening degradation behavior and the variables are used to derive the damaged stiffness matrix. The damaged stiffness matrix is reflected to damaged material and the progressive failure analysis is continued until the damage variables to be 1 that complete failure of material. A series of processes were performed using FE commercial code ABAQUS with user defined material subroutine (UMAT). To evaluate the proposed progressive failure model, the experimental results of open hole composite laminate tests was compared with numerical result. Using digital image correlation system, the strain behavior also was compared. The proposed numerical results were coincided well with the experimental results.