• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.73-77
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• 2008

In this study, we would like to study on the application of roof exposure waterproofing method of joint stability through shiplap rubberized asphalt color sheet to complement problem of fracture, exfoliation and water leakage by existing roof exposure sheet waterproofing material joint weakness. Accordingly, examined basis performance and stability for joint that shiplap rubberized asphalt color sheet through test of that tensile strength, bonding strength, water permeability after bonding, peel resistance after bonding, lengthen resistance after bonding and hang resistance after bonding. The results of this study, waterproofing method to using shiplap rubberized asphalt color sheet is judged to solved fracture, exfoliation and water leakage problems happened in joint by problem was joint of exposure sheet by minimizing gap of joint being integration by shiplap.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.2
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• pp.121-129
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• 1993

Plane strain punch stretching test (PSST) was developed to evaluate stamping formability of sheet materials. In this test, the rectangular specimen of sheet material is uniformly stretched up to fracture by raising a specially designed punch to certainly assure plane strain stretching deformation along the longitudinal direction of the specimen. The stamping formability was evaluated by limit punch height(LPH) in plane strain punch stretching test compared to limit dome height(LDH) in hemispherical punch stretching test. LPH-value in PSST well ranks the stamping formability of various material and correlates with press performance. Moreover by using ultrasonic thickness gauge the plane strain intercept-limit plane strain(FLCo)-in forming limit curve can be accurately determined from thickness measurement around the fracture area. The FLCo derived from thickness measurement well correlates with the results from circle grid analysis for the deformed circle grid marked on the surface of the specimen.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.104-105
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• 2006

The low-cycle fatigue performance and fracture of the P/M Ti-Fe-Mo-Al-Nd Alloys after sintering and forging have been studied. The linear regression equation of low-cycle fatigue lifetime has been obtained; the fatigue performances are objected under two different conditions. The fatigue fracture surface is analyzed by SEM. The low-cycle fatigue behavior of the P/M titanium alloy has been discussed.

• Coupled systems mechanics
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• v.7 no.6
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• pp.669-690
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• 2018

This paper deals with numerical modeling of dynamic failure phenomena in rate-sensitive brittle and/or ductile materials. To this end, a two-dimensional continuum viscodamage-embedded discontinuity model, which is based on our previous work (see Do et al. 2017), is developed. More specifically, the pre-peak nonlinear and rate-sensitive hardening response of the material behavior, representing the fracture-process zone creation, is described by a rate-dependent continuum damage model. Meanwhile, an embedded displacement discontinuity model is used to formulate the post-peak response, involving the macro-crack creation accompanied by exponential softening. The numerical implementation in the context of the finite element method exploiting the second-order mid-point scheme is discussed in detail. In order to show the performance of the model several numerical examples are included.

• Journal of the Korean Ceramic Society
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• v.56 no.1
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• pp.77-83
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• 2019

MgO-C refractories are used in basic furnaces and steel ladles due to their many desirable properties, such as excellent thermal shock resistance via low thermal expansion, and high thermal conductivity. However, the mechanical and thermal properties of the refractory continuously deteriorate by spalling phenomena and pore generation due to the oxidation of graphite, used as a carbon source, indicating that the characteristics and performance of MgO-C refractories need to be improved by using a new material or composition. In this study, the use of a Hertzian indentation test as a method for determining the damage and fracture behavior of an MgO-C refractory is described. The results highlight that Hertzain indentation tests can be one of the important evaluation tools for quasi-plastic damage accumulation of MgO-C refractories during falling process of scrap metal.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.3
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• pp.16-23
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• 2021

The fracture characteristic of the bonded interface under the application of a sliding load to a double cantilevered specimen manufactured using lightweight material was examined. Inhomogeneously bonded materials such as Al6061-T6, CFRP, and CFRP-Al were employed. In the experiment, the specimen was loaded on both directions by applying a shearing load to the bonding interface. The experimentally obtained stress, specific strength and energy release rate values were examined. CFRP exhibited excellent specific strength. The experimental results demonstrated that the inhomogeneous bonded material CFRP-Al exhibited an overall high performance in comparison with the single materials.

• Clinics in Shoulder and Elbow
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• v.19 no.4
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• pp.223-228
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• 2016

Background: The aim of study was to confirm the clinical effectiveness and results of wide and single anterior approach for fractures occurring along length of humerus. Methods: A total of 23 patients with humeral fracture were enrolled into our study who were able to participate in at least one year of follow-up. Seven patients had segmental comminuted humeral fractures and 16 patients had distal humeral fractures. We made various tractions of the muscles to expose the proximal and the middle third humerus between the biceps and brachialis and the distal humerus by partial splitting of lateral side of biceps through a single incision. Postoperatively, we measured the Mayo elbow performance index (MEPI). Results: we achieved bone union in all 23 patients. Solid union of the bone was achieved at an average 13.9 weeks. Postoperatively, two complications were observed screw loosening and nonunion. Revision surgery was performed in both patients. The patient with bone nonunion was treated using bone grafts. No postoperative infections or peripheral neuropathies were observed. At the final follow-up (average 20 months), we found that the average MEPI functional score of the patients was 91.7 points regardless of the fracture site. Conclusions: Our whole humerus with a single incision was effective for the treatment of segmental comminuted and distal fractures. we believe it is a useful alternative to preexisting methods of fracture fixation.

• Clinics in Shoulder and Elbow
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• v.23 no.1
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• pp.20-26
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• 2020

Background: High complication rate after open reduction and internal fixation can lead to use of primary total elbow replacement (TER) in treatment of complex distal humerus fractures in elderly patients. The purpose of this study was to investigate the short-term outcomes and complications after primary TER in patients with complex distal humerus fracture. Methods: Nine patients with acute complex distal humerus fracture were treated by primary TER using the semiconstrained Coonrad-Morrey prosthesis. The mean age of patients was 72.7 years (range, 63-85 years). Clinical and radiographic outcomes were evaluated over a mean follow-up of 29.0 months (range, 12-65 months) using visual analog scale (VAS) score for pain; Mayo elbow performance score (MEPS); Quick Disabilities of the Arm, Shoulder, and Hand (Quick-DASH) score; and serial plain radiographs. Complications were also evaluated. Results: At the final follow-up, mean VAS, MEPS, and Quick-DASH scores were 1.2, 80.5, and 20, respectively. The mean range of motion was 127.7° of flexion, 13.8° of extension, 73.3° of pronation, and 74.4° of supination. There was no evidence of bushing wear or high-grade implant loosening on serial plain radiographs. Three complications (33.3%) comprising two periprosthetic fractures and one ulnar neuropathy were observed. Conclusions: Primary TER for treatment of complex distal humerus fractures in elderly patients yielded satisfactory short-term outcomes. However, surgeons should consider the high complication rate after primary TER.

• Clinics in Shoulder and Elbow
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• v.21 no.3
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• pp.120-126
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• 2018

Background: Treatment of distal humerus fractures in osteoporotic elderly patients is often challenging. For non-reconstructible fractures with open reduction and internal fixation, total elbow arthroplasty (TEA) is an acceptable alternative. However, the relatively high complication rates and lifelong activity restrictions make TEA less ideal for elderly or low-demand patients. Efforts to identify or develop alternate procedures that benefit relatively young, high-demand patients have resulted in increased interest in hemiarthroplasty. This systematic review reports the clinical outcomes of hemiarthroplasty for distal humeral fractures. Methods: We systematically reviewed the databases of PubMed, Ovid MEDLINE, and Cochrane Library. All English-language studies published before June 2017 were considered for possible inclusion. Search terms included 'distal humerus fracture' and 'hemiarthroplasty'. Studies reporting outcomes (and a minimum of 1 year clinical follow-up) in human subjects after hemiarthroplasty (Latitude system) for distal humeral fractures were assessed for inclusion. Patient demographics, clinical and radiographic outcomes, and complications were recorded, and homogenous outcome measures were analyzed. Results: Nine studies with a total of 115 patients met the inclusion criteria. Among the included studies, the weighted mean follow-up time was 35.4 months. Furthermore, the weighted mean of the postoperative range of motion ($107.6^{\circ}$ flexion-extension, $157.5^{\circ}$ for pronation-supination) and functional outcomes (Mayo elbow performance scores: 85.8, Disabilities of the Arm, Shoulder and Hand score: 19.6) were within the acceptable range. Conclusions: Our study indicates that hemiarthroplasty is a viable option for comminuted distal humerus fracture. Satisfactory functional outcomes were observed in most patients.

• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.861-867
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• 2015

The Compact Tension (CT) type test was performed in order to evaluate the fracture toughness performance of glass fiber-reinforced laminated timber. Glass fiber textile and sheet Glass fiber reinforced plastic were used as reinforcement. The reinforced laminated timber was formed by inserting and laminating the reinforcement between laminated woods. Compact tension samples are produced under ASTM D5045. The sample length was determined by taking account of the end distance of 7D, and bolt holes (12 mm, 16 mm, 20 mm) had been made at the end of artificial notches in advance. The fracture toughness load of sheet fiberglass reinforced plastic reinforced laminated timber was increased 33 % in comparison to unreinforced laminated timber while the glass fiber textile reinforced laminated timber was increased 152 %. According to Double Cantilever Beam theory, the stress intensity factor was 1.08~1.38 for sheet glass fiber reinforced plastic reinforced laminated timber and 1.38~1.86 for glass fiber textile reinforced laminated timber, respectively. That was because, for the glass fiber textile reinforced laminated timber, the fiber array direction of glass fiber and laminated wood orthogonal to each other suppressed the split propagation in the wood.